Lumbriculus (Clitellata: Lumbriculidae), as we present a case for revisiting the use of an annelid model system for the study of regeneration. We hope that this review will provide a primer to Lumbriculus biology not only for regeneration researchers but also for STEM teachers and their students.The mechanisms supporting regeneration and successful recovery of function have fascinated scientists and the general public for quite some time, with the earliest description of regeneration occurring in the 8th century BC through the Greek mythological story of Prometheus. While most animals demonstrate the capacity for wound-healing, the ability to initiate a developmental process that leads to a partial or complete replacement of a lost structure varies widely among animal taxa. Variation also occurs within single species based on the nature and location of the wound and the developmental stage or age of the individual. Comparative studies of cellular and molecular changes that occur both during, and following, wound healing may point to conserved genomic pathways among animals of different regenerative capacity. Such insights could revolutionize studies within the field of regenerative medicine. In this review, we focus on several closely related species of  Regeneration—the ability to regrow body parts lost to injury—has fascinated scientists and the general public at least since the 8th century BC, as shown by the Greek myths of the Lernaean Hydra or Prometheus and his continuously regenerating liver. Although most animals demonstrate capacity for wound-healing, the ability to initiate a developmental process leading to partial or complete replacement of a lost structure varies widely among animal taxa . Given tDrosophila fruit flies, Mus mice, C. elegans nematodes) served as good regenerative models, prompting the need for the development of alternative models to study this biologically and medically important phenomenon. Along with planarians, cnidarians, arthropods and amphibians, marine, freshwater, and terrestrial annelids have been a traditional alternative to study regeneration, and they still provide an excellent platform for this purpose. Many annelid lineages show amazing abilities to regrow an entire new body from a single fragment, while others (sometimes closely related) find themselves incapable of regenerating heads, or even tails . Also known as blackworms, they are taxonomically related to leeches and other mud-dwelling clitellates. Some species can regenerate an entirely new body from a fragment only 1/50th the size of the original animal. Such remarkable regenerative capabilities include the ability to recover structure and function along most of the anterior-posterior body axis. In addition, Lumbriculus worms subjected to long-term deprivation of nutrients will still direct resources to regeneration following amputation, further attesting to the high regenerative capacity of this annelid  advised by the renowned embryologist E. B. Wilson, and later at the University of Zürich (Switzerland) helped by A. Lang. Her results were published in a seminal pair of publications, in which she proposed that several mesodermal structures in the regenerate derived from segmentally iterated reserve mesodermal stem cells, which she named neoblasts, that laid dormant on the peritoneal epithelium, lateral to the ventral nerve cord  and posterior (tail) regeneration . After tImmediately after amputation, body wall circular muscles located adjacent to the cut site contract quickly to close off the coelomic cavity and minimize contact with the external medium. Sometimes, this fast movement closes the body wall around the cut end of the gut, which is left protruding; if this happens, the gut withdraws or pinches off the exposed end. Usually, epithelial cells from the epidermis at the edges of the cut extend to cover and seal the wound, and the same happens with the gut epithelium, which closes forming a blind end; in some cases, the edges of the epidermis and gut come into contact and fuse directly instead, closing out the wound and restoring a posterior opening . At thisSoon after wound healing, neurites originating in nerves from the ventral nerve cord and peripheral nerves invade the wound site . Around After accreting, the blastemal mass begins to differentiate into distal non-segmental regions: a cone-shaped prostomium in anterior regenerates  and an aIn posterior regenerates, ventral epidermal proliferation, and cell ingression, potentially along with the neoblast progeny, give rise to the primordia of the new posterior growth zone, along with the posterior ventral nerve cord ganglia . At the de novo .This results in a taxonomic dilemma, as the ploidy of the type species described by ructures . Others mic keys  provide Lumbriculus when exposed to a variety of environmental stresses?The occurrence of both diploid and polyploid populations imposes a taxonomic challenge, but also provides unique opportunities for investigations of regeneration within these contexts. Since ploidy levels impact physiology, gene expression, response to environmental stresses, and rates of cell proliferation, comparative studies could be conducted, examining the impact of chromosome numbers on wound healing and downstream events occurring during regeneration. What potential differences are there in the regeneration process between diploid and polyploid forms of the worms? Are there differences in the regenerative capacity of a diploid, sexually mature worm producing cocoons compared to that of polyploid asexually reproducing worm? What differences in responses might be observed through comparative transcriptomics between diploid and polyploid Lumbriculus, the role of these cells has been hotly debated. Lumbriculus were exposed to x-rays to inhibit mitosis. Non-irradiated tissues, through histological analysis, showed proliferation of ectodermal cells that were linked to regeneration of nerve ganglia and the ventral nerve cord. Other cells thought to be neoblasts appeared to migrate to the wound site where they proliferated and gave rise to blood vessels and muscle cells in the regenerating tissue. Lumbriculus were treated with colchicine and vinblastine, inhibitors of cell proliferation, prevented regeneration of heads and tails  is still unclear.Despite a long history of study, definitive evidence of neoblast migration is still scarce: wound-directed migration of neoblast-like cells has only recently been directly observed using time-lapse imaging in the freshwater clitellate a leidyi . HoweverThe oligochaete central nervous system (CNS) generally consists of a cerebral ganglion  which is located in prostomium and is connected to the subesophageal ganglion and subsequently a ventral nerve cord (VNC) via two circumesophageal connectives . In lumbLumbriculus exhibits anterior-posterior gradients in behavior that are easily monitored  are mediated by the giant fiber pathways. Activation of these giant fibers via sensory stimuli (e.g. tactile or photic) results in the rapid conduction of nerve impulses down the length of the fiber that, in turn, activate motor neurons, which impinge upon longitudinal muscles responsible for body shortening . MoreoveLumbriculus: regeneration occurs only in the presence of a cut end of the VNC, and the blastema begins to form next to the VNC end; furthermore, extirpation of fragments of the VNC results in the formation of ectopic lateral regenerates, adopting anterior (head) or posterior (tail) morphologies depending on the facing of the cut VNC end  , and genLumbriculus research into the modern molecular era. Gene expression analyses are powerful tools for screening of genes that may be involved in regeneration. Thus, the development of techniques for gene expression analysis is of utmost importance. A step toward this work is the optimization of real-time PCR protocols by the Martinez Acosta and Gillen labs which will reliably quantify expression of genes of interest , which regulate sexual development, differentially expressed in tissues from sexually reproducing worms? How similar or different are they to DM proteins from other animals? Characterization of these proteins would provide insights into mechanisms leading to sexual versus asexual modes of reproduction in Lumbriculus.Culturing of r months . The Drer months . Access Lumbriculus research beyond correlation and shift the focus of future work toward demonstrating the functional significance of gene expression changes. In particular, successful application of reverse genetic techniques such as RNA interference (RNAi) and the CRISPR-Cas endonuclease system would allow assessing gene function and drastically change the playing field for Lumbriculus regeneration studies. Work aimed to develop these techniques is already ongoing in several labs, and this research has benefited from fluid communication, data and resource exchange, and collaborative work.Further development of genomic methods will move Lumbriculus variegatus , which has been implicated in regeneration in mammals , Eastern Aquatics , and Aquarem , that sell them as blackworms or mudworms for use in aquaculture. Various biological stores sell Lumbriculus for educational purposes, providing supporting curriculum kits directly to K-12 biology teachers, like Carolina Biological  and Flinn Scientific . Lumbriculus can also be obtained from the Environmental Protection Agency (EPA) Laboratory in Duluth, MN, United States where a culture has been maintained since the 1980s. All of these sources of Lumbriculus derive from polyploid populations, with chromosome counts compatible with at least 11-ploid to 12-ploid worms . Microbes in the cultures also serve as a source of nutrition. Strips of brown paper towels are added to mimic the leaf litter of natural habitats. For bioaccumulation experiments, sandy or other fine sediment types can be added to the cultures  found that salt provokes release of ectoparasites from the surface of the worms. Overall, the general culturing of Lumbriculus is carried out with ease, thus providing a reliable source for experimentation.Whether obtained commercially or collected from the environment, cultures . Some laneration . As the Lumbriculus was first proposed by Charles Lumbriculus. Through detailed supply lists, descriptions of techniques, and examples of experimental design, Drewes described how students could generate and maintain worm fragments in the teaching lab. Through observations of regenerating fragments, students then learn about morphallaxis, the developmental process of reorganization that occurs as Lumbriculus regenerates anterior segments. As restoration of tissues and anatomical structures such as blood vessels are monitored, anterior regeneration is compared to posterior regeneration. Students also explore the influence of amputation location along the anterior-posterior axis and fragment size on numbers of regenerated segments. Generation in the laboratory of worm fragments by amputation severs the ventral nerve cord, disrupting the locomotory responses typical of anterior and posterior regions of Lumbriculus. As students monitor the fragments for recovery of different locomotory functions such as swimming, crawling, reversal behaviors, the role of the nervous system in the regenerative process can be explored , we think that the advantages of this organism—ease of procurement and culture, fast and robust regenerative abilities, rich research history, considerable ecological and genetic diversity, and a large spectrum of open questions with significant biological and biomedical relevance—render it a superb organism for regeneration research, either in a science research lab or in elementary, middle and undergraduate classrooms. We hope this review article will foster further work on Lumbriculus regeneration in research labs and encourage expanded use of these worms in the teaching labs; in turn, the work and questions of students are bound to spark new ideas for the research lab. Two heads are better than one.Thanks to the work of past and present researchers working on


Recent years have witnessed a dramatic increase in the use of theoretical and computational approaches in the study and development of molecular imprinting systems. These tools are being used to either improve understanding of the mechanisms underlying the function of molecular imprinting systems or for the design of new systems. Here, we present an overview of the literature describing the application of theoretical and computational techniques to the different stages of the molecular imprinting process , along with an analysis of trends within and the current status of this aspect of the molecular imprinting field. Molecular imprinting has been defined as: “The construction of ligand selective recognition sites in synthetic polymers where a template  is employed in order to facilitate recognition site formation during the covalent assembly of the bulk phase by a polymerization or polycondensation process, with subsequent removal of some or all of the template being necessary for recognition to occur in the spaces vacated by the templating species” .The most central feature of the molecular imprinting concept ,2,3,4,5 Consequently, the molecular and physical characteristics of recognition sites in MIPs result directly from the various interactions possible in the pre-polymerization mixture, e.g., template–monomer, monomer–monomer, solvent–template/monomer, etc. An appreciation of the physical rules governing the formation of these complexes is therefore crucial for understanding the complexity of the imprinting process. If we are to achieve true rational design of molecularly imprinted systems for producing materials with predetermined recognition properties, suitable tools that can provide insight into the molecular recognition processes are needed.Although classical thermodynamic models  in theorGbind) is the combined energy changes associated with the loss of translational and rotational freedom (ΔGt+r), restriction of rotors upon complexation (ΔGr), hydrophobic interactions (ΔGh), residual soft vibrational modes (ΔGvib), the sum of interacting polar group contributions (∑ΔGp), adverse conformational changes (ΔGconf) and unfavorable van der Waals interactions (ΔGvdW).The physical factors underlying molecular interaction have attracted the interest of researchers for several decades. Jenck’s paradigms ,11, the Gbind. The position of this equilibrium dictates the number and heterogeneity of the resulting binding sites. Stronger and more regular template-functional monomer complexes are thus expected to lead to a larger number of sites with higher fidelity. The degree of template complexation by a functional monomer and the degree of heterogeneity are determined by the chemical nature of the pre-polymerization mixture and the polymerization conditions (temperature and pressure).The recognition properties of MIPs result from pre-polymerization complexation between template and functional monomer, an equilibrium process governed by the free energy of binding, ΔAn investigation of changes in NMR chemical shifts and line broadening with increasing functional monomer concentration offered the first direct verification of the formation of non-covalent template-functional monomer complexes . This stGt+r, associated with the loss of translational and rotational freedom. Higher-order complexes, expected to produce higher-fidelity binding sites, thus have a larger energy barrier. It follows that using a functional monomer capable of multiple simultaneous interactions should produce increased concentrations of complexed template, compared to an increased concentration of a single-point monomer. Although multi-dentate monomers are not as easily available and often require synthesis, examples of their use in MIPs have been reported [Complex formation between a template and a functional monomer carries with it an entropic penalty, Δreported ,30,31,32Gt+r, the ΔGr term is the penalty for restricted internal bond rotation upon complexation. Thus, interactions with rigid templates are entropically favored and the resultant MIPs tend to exhibit higher selectivity than those prepared with less rigid structures. In addition, a rigid structure can adopt fewer solution conformations, which leads to a narrower site distribution. Consequently, high MIP–ligand affinities have been observed for rigid templates, such as the alkaloids morphine [Similar to Δmorphine  and yohimorphine .Gp term. Examples have been reported where selectivity was enhanced by using more strongly interacting monomers [MIPs have traditionally been prepared in non-polar organic media, thus relying on polar interactions to drive the equilibrium towards complexation, as reflected in the ∑Δmonomers ,36,37,38monomers . In addimonomers ,42,43,44Gh term of Equation (1). This enables functional monomers with hydrophobic moieties to facilitate template complexation through the hydrophobic effect. Some interesting examples have been reported where polymerizable cyclodextrins were used as monomers [When the analyte of interest is water-soluble or otherwise incompatible with the commonly used non-polar organic solvents, other methodologies are required. For many important classes of analytes, e.g., peptides, proteins, oligonucleotides and sugars, the use of water as the porogen (solvent of polymerization) places a strong influence on the Δmonomers ,47,48,49Gbind, as defined by the different thermodynamic terms in Equation (1). The magnitudes of the individual terms are determined by the chemical nature of all components in the mixture as well as the physical conditions during polymerization. Thus, the conceptually simple process of molecular imprinting is based on a complex series of highly interdependent equilibria, inevitably leading to polymers with heterogenous distributions of recognition sites. The same thermodynamic principles, of course, also apply to interactions between the polymer and its analyte/target in the intended application, further complicating the link from pre-polymerization conditions, over polymerization and work-up, to final use. Accordingly, there is a need for methodologies to study and understand the complexity of pre-polymerization events, to correlate these events with MIP performance and to optimize all stages of MIP synthesis.In summary, for non-covalently imprinted polymers, the selectivity and affinity of the MIP is controlled by the various equilibria present in the pre-polymerization mixture. The positions of these equilibria are, in turn, governed by ΔDriven by the rapid development of molecular imprinting and its applications, several tools for in silico studies of the above-mentioned stages of MIP design and synthesis have been adopted. These tools can offer atomistic insights on aspects ranging from events in the pre-polymerization mixture to polymer–ligand interactions and even polymer morphology. Since the first applications of computational strategies to study aspects of molecular imprinting in the beginning of the 21st century, the field has grown steadily, and particularly over the last decade . This deIn the past, knowledge of the molecular events underlying MIP behavior has been extracted from empirical studies of polymer–ligand interactions. Thermodynamic models ,17,50,51The major reason behind the recent increase in the use of computational strategies in MIP technology is likely related to increased affordability of computational power and access to appropriate software ,56,57,58The use of computational methods based on electronic structure calculations, e.g., ab initio, semi-empirical and density functional theory (DFT) strategies, for the design and evaluation of MIPs is increasing. This class of computational methods, collectively termed quantum chemistry, aims to solve the electronic Schrödinger equation based on the atomic coordinates and number of electrons of the system studied. This is impossible for systems with more than a few electrons, and therefore approximations are necessary. Ab initio methods approximate the electronic wavefunction, whereas semi-empirical and DFT methods instead approximate the Hamiltonian operator. The accuracy, and computational demand, increases from semi-empirical methods  to DFT , and finally ab initio methods. Different strategies, basis sets and parameters are chosen to provide an acceptable approximation of the system studied within a reasonable timeframe. Typically, comparing quantum chemical calculations for isolated molecules and molecular complexes can provide information regarding interaction strength and type, and consequently, these methods are very often used for evaluation of different template–monomer combinations.Although the development of modern MD methodology was closely intertwined with that of Monte Carlo simulations ,61,62,63In comparison to electronic structure methods, MD simulations require less computational resources when treating systems of comparable size. This enables studies of much larger multimolecular systems, including MIP pre-polymerization mixtures containing thousands of molecules, with reasonable demands on both hardware resources and time. However, since electrons are not explicitly considered, MD simulations are unable to account for processes involving the movement of electrons, such as bond breaking or formation. Nevertheless, important information can be attained regarding the multitude of non-covalent interactions taking place in pre-polymerization mixtures as well as in MIP binding site models .Molecular imprinting and its applications, with nearly infinite combinations of pre-polymerization components, polymerization conditions, polymer workup, evaluation parameters and analytic responses, lends itself well to multivariate analysis ,92,93. TApplication of multivariate methods usually begins with determining which parameters to study and then choosing an experimental design that allows for simultaneous evaluation of these parameters. Often, a pilot or training set of experiments is performed to determine which of the variables have the largest effect on the outcome, followed by a more focused, second experimental design in order to produce models for prediction or optimization. Common experimental designs include full or fractional factorial, Box-Behnken, Placket-Burman, Doehlert and central composite designs .The experimental data can be calibrated, or fitted, to mathematical models using a number of methods. In MIP studies, the most common are principal component analysis (PCA), partial least squares regression (PLSR), multiple linear regression (MLR) and artificial neural networks (ANN).As seen in Demands on hardware resources and simulation time both increase rapidly with the size of the system under investigation. Accordingly, the most common use of electronic structure-determining methods in MIP studies for characterization of template–monomer complexes, as discussed above, is to find the most suitable functional monomer and often also the optimal stoichiometry. Of the electronic structure-determining methods, semi-empirical strategies are less demanding on computational resources, and the two most commonly used semi-empirical methods for MIP development are AM1 ,105,106 The more computationally demanding ab initio and DFT methods provide higher accuracy. Investigations involving template–monomer complex studies have employed different methods, basis sets and levels of theories on several occasions. The majority of these studies employed DFT methods ,296,297,The growing accessibility of computational power has been accompanied by an increasing frequency of reports in the literature including quantum chemical calculations in the design and characterization of MIPs. Due to relatively high resource requirements associated with these calculations, most studies have focused primarily on subsets of pre-polymerization mixtures, restricted sets of interactions or isolated non-solvated molecular complexes in vacuo. With seemingly ever-increasing availability of computational power and emergence of novel mixed approaches combining electronic structure and MD simulations, increased use of electronic structure methods in the design and study of molecular imprinting systems is expected.The nature of MD simulations makes them highly suited for studies of liquid systems, and with the assumption that MIP recognition properties originate from pre-polymerization interactions ,326,327,In a method introduced by Piletsky et al., 20 functional monomers were initially assessed for their interaction energy with the template ephedrine in both charged and neutral states . SelecteDespite the dramatic development of computer hardware and software, multimolecular simulations involving multiple copies of monomers, template and explicit solvent are still not feasible for electronic structure methods alone. However, several examples report the combined use of quantum chemical calculations and MD simulations to study different aspects of pre-polymerization mixtures ,393,394.The growing number of MD studies of systems containing all MIP components and with experimental stoichiometries have highlighted the importance of these more comprehensive treatments of pre-polymerization mixtures for delineating underlying mechanisms ,412,413.MD-based investigations of other aspects of the pre-polymerization stage include studies of the structural stability of protein epitopes for template screening ,415, mapTraditionally, analysis and optimization of MIPs have been univariate in nature. This involves evaluation and optimization of one parameter with the results carried forward for optimization of the next, and so forth. This may not always be ideal as identified optima may turn out to be local or false . The inhThe polymerization reaction is the least studied aspect of molecular imprinting in general as well as in the context of computational treatment b. The imAlthough this class of computational methods can accurately describe the movement of electrons and the breaking and formation of chemical bonds, the number of molecules required for a meaningful representation of the polymerization process of a MIP would lead to unreasonable computational demands. Hopefully, the technical development will eventually allow such calculations, yet to the best of our knowledge, no examples have been published.A few attempts have been made to apply MD to the study of MIP polymerization. Yungerman and Srebnik used a coarse-grained Monte Carlo procedure to study the formation of binding site imperfections in MIPs . MonomerThe application of multivariate strategies in order to optimize polymerization conditions has been rare so far. Examples include studies of optimum polymerization temperature when comparing polymerization in bulk and surface molecular imprinting to study the role of insulin-imprinted magnetic nanoparticles , investiThe bulk of the computational studies of MIP properties post-polymerization use multivariate analysis, though a handful of reports using quantum chemical calculations or MD simulations have also been presented d–f. ThisElectronic structure methods have been used in a few instances to study aspects of MIP–template recognition. These include PM3 calculations of a binding site model for nicotinamide , AM1 calAttempts at simulating aspects of the rebinding of a template or ligand to a MIP using force field-based methods have also been reported. In several studies, polymer models have been approximated by equilibrating templates with linear chains of functional monomers, followed by analysis of binding energies and other aspects of recognition ,514,515 The experimental conditions employed when evaluating or applying MIPs have a major influence on the performance of the polymer. Similar to the situation in the pre-polymerization mixture, the possible combinations of experimental parameters  are nearly endless, making this an area highly suited for multivariate optimization. Thus, different combinations of experimental designs and response surface modeling have been used for optimization of parameters when using MIPs in adsorption, separation or sensing applications ,633,634.In other cases, multivariate methods have been used to reveal correlations hidden in the data obtained when evaluating MIPs. Different combinations of PCA and PLSR methods have been applied for interpretation of MIP binding data obtained from SERS (surface-enhanced Raman spectroscopy) ,643,644,A separate branch of multivariate analysis of chemical data is called chemometrics, in which large numbers of structure-derived properties, molecular descriptors, are generated for a set of molecules and then correlated with other properties of interest. Thus, a number of studies have been reported attempting to correlate molecular descriptors with MIP binding data using a range of multivariate tools. Rossetti et al. employed PLS models to correlate molecular descriptors with solid-phase extraction retention data for a series of biomarker pro-gastrin-releasing peptides in order to elucidate the recognition mechanism . Liu et The significant growth in the number of literature reports describing computational studies of molecular imprinting systems has followed the development, availability and affordability of both hardware and software. In turn, this has enabled the use of these tools in both prognostic and diagnostic capacities in the development of molecularly imprinted materials. This development and the growing awareness of the value of the use of these tools is reinforced through validation using experimental studies. Accordingly, the combination of ready access to these computational tools and the value of the insights gained from their use should see further increases in the prevalence of their use in the molecular imprinting field.


Hedgehogs have a sensitive olfaction, but little is known about their vomeronasal organ, which detects specific chemicals such as pheromones. This is the first study to reveal the morphological and histological features of the vomeronasal organ in the African pygmy hedgehog. Notably, unlike other mammals, the hedgehog has a large, well-developed serous gland in the vomeronasal organ. This gland seems to allow flushing out odorous substances from the vomeronasal organ and might be favorable for subsequent stimulus reception.The vomeronasal organ (VNO) detects specific chemicals such as pheromones and kairomones. Hedgehogs (Eulipotyphla: Erinaceidae) have a well-developed accessory olfactory bulb that receives projections from the VNO, but little is known about the hedgehog VNO. Here, we studied the histological features of the VNO in five individual African pygmy hedgehogs by hematoxylin-eosin, periodic acid-Schiff, and Alcian blue stains. The hedgehog VNO comprises a hyaline cartilage capsule, soft tissue and epithelial lumen, and it branches from the site just before the incisive duct opening into the nasal cavity. The soft tissues contain several small mucous (or mucoserous) glands and a large serous gland, and many venous sinuses all around the lumen. The VNO lumen is round to oval throughout the hedgehog VNO, and the sensory epithelium lines almost the entire rostral part and medial wall of the middle part. These findings indicate that the VNO is functional and plays an important role in the hedgehog. Notably, the VNO apparently has a characteristic flushing mechanism with serous secretions like those of gustatory glands, which the hedgehog might frequently use to recognize the external environment. Most mammals detect environmental chemicals using main olfactory and vomeronasal systems. The vomeronasal organ (VNO) detects specific chemicals that benefit animals, such as pheromones and kairomones, which are respectively released by the same and other species .The mammalian VNO composes a cartilage (or bone) capsule, highly glandular and vascular soft tissue, and an epithelial lumen with a blind end at the caudal side, and a species-specific rostral orifice ,3. The lAtelerix albiventris ) inhabit the savannah and steppe regions of central and eastern Africa and they are bred as pets. They have a sensitive olfactory system, and olfaction seems to play key roles in behavioral navigation, food and predator detection, and conspecific communication [Hemiechinus auritus) [Hedgehogs  are most closely related to shrews (family Soricidae) . Wild Afnication . Hedgehonication , and thenication , indicatnication  describeauritus) . To veriAtelerix albiventris ) were studied. The heads of three males (age 2.5–3.5 years) and two females (age 2 and 3.5 years), all mature, were obtained from sacrificed control animals of the other experiment not related to this study, approved by the Animal Care and Use Committee of Obihiro University of Agriculture and Veterinary Medicine (OUAVM) . The heads were fixed in 15% neutral-buffered formalin for 3–7 days at room temperature, then used in the following procedures. The Animal Care and Use Committee of OUAVM was notified of the experimental protocol (notification numbers: 21–8), and the study proceeded according to Institutional Regulations on the Management and Operation of Animal Experiments.A total of five African pygmy hedgehogs (n = 1 each) were processed for macroscopic anatomical assessment of the VNO before the histological process described below, to confirm the location and length. The left lateral and basal walls composing the maxilla, palatine, and nasal bones were removed. Images of the left VNO attached to the nasal septum, in addition to the rostral part of the palate, were acquired using a STYLUS TG-3 Tough digital camera .Male and female heads  located at the basal part of the nasal septum. The VNO started at the first incisor in the longitudinal direction and ended near the first premolar A. The inThe vomeronasal cartilage continued from that covering the incisive duct D–F, and Two types of secretory glands were associated with the hedgehog VNO. Several small glands were located immediately below non-sensory epithelium in the lateral portion of the middle area C, and acThe lumen was round-to-oval in the cross section throughout the VNO . The lumSensory epithelium was pseudostratified and comprised receptor, supporting and basal cells A. The nuThe present findings of the hedgehog VNO, described above, are summarized as The histological features of the sensory epithelium in African pygmy hedgehog VNO are similar to those in other mammals that depend on the vomeronasal system . This fiThe hedgehog VNO connects to the incisive duct just before the nasal cavity. The VNO of most carnivores ,15,16,17The vomeronasal capsule consists of cartilage in most mammalian species, including carnivores ,16,17, uThe hedgehog VNO contains several small mucous glands and a well-developed serous gland. The VNO of brown bears also has two types of glands, but both are mucous . Glands The most notable finding in this study is the well-developed serous gland associated with the hedgehog VNO. Reports indicated some serous-type cells in the mammalian vomeronasal glands ,39,40, bCryptomys hottentotus and Fukomys damarensis, have venous sinuses that widely surround the lumen, whereas venous sinuses in Heterocephalus glaber mole rats with a crescent-shaped lumen are limited to the lateral region of the VNO [The lumen of the VNO is round-to-oval throughout its entire length in the African pygmy hedgehog. It is also oval in common marmosets  and some the VNO . These fThis is the first study to reveal the morphological features of the VNO in the African pygmy hedgehog. Unlike other mammals, the hedgehog has a well-developed serous vomeronasal gland in the VNO. The lumen of the hedgehog VNO is oval, like secretory gland ducts, and the venous sinuses around the lumen appear to pump against it. These morphological features seem to allow the removal of odorous substances from the VNO and might be favorable for receiving subsequent stimuli.


The gut microbiota is composed of several microbial strains, with diverse and variable combinations in healthy and sick persons, changing at different stages of life. A healthy balance between host and gut microorganisms must be maintained in order to perform the normal physiological, metabolic, and immune functions and prevent disease development. Disturbances in the balance of the gut microbiota by diverse reasons initiate several health issues and promote the progression of certain diseases. This review is based on published research and reports that describe the role of probiotic microorganisms in the sustainability of health and the alleviation of certain diseases. Information is presented on the GRAS strains that are used as probiotics in the food industry for the production of fermented milk, yogurt, fermented food, functional foods, and probiotic drinks. To maintain a healthy microbiota, probiotic supplements in the form of freeze-dried live cells of probiotic strains are also available in different forms to consumers. The health benefits of lactic acid bacteria and other microorganisms and their role in the control of certain diseases such as gut inflammation, diabetes, and bowel cancer and in the safeguarding of the gut epithelial permeability from the invasion of pathogens are discussed. Gut microbiota or gut microbiome is a collective term for those microorganisms that live in all vertebrates’ gastrointestinal tract (GIT). In humans, the gut is the main site for the survival of the human microbiota. The microbiota in the gut consists of several strains of bacteria and yeasts. With its diversity, its composition fluctuates at different stages of life and varies in healthy and sick persons . The relAn individual’s microbiota plays a vital role in the sustainability of health and the development of diseases ,4. Many Natural or processed foods that contain biologically active ingredients are termed functional foods. These, also known as nutraceuticals, can be defined as food containing additives that provide nutritional value with extra health benefits. Several reports established that the gut microbiota can be targeted and manipulated by suitable dietary means to prevent several temporary health issues and alleviate some diseases . ResearcLactobacillus, Levilactobacillus, Lacticaseibacillus, Limosilactobacillus, Lactococcus, Pediococcus, Enterococcus, Leuconostoc, Oenococcus, Streptococcus, Tetragenococcus, Aerococcus, Carnobacterium, Weissella, Alloiococcus, Symbiobacterium, and Vagococcus) and more than 300 species [The definition of probiotics according to the Food and Agriculture Organization/World Health Organization is “Live microorganisms which when administered in adequate amounts confer a health benefit on the host” ,12. Prob species ,15. Tabl2. All these metabolites can play a role in the competition of LAB with other microorganisms during fermentation [Lactococcus and Lactobacillus have been given a GRAS status, the LAB genus Streptococcus and certain other species have been granted a GRAS/QPS status, whereas none of the species of the genus Enterococcus have been granted a GRAS/QPS status yet [The microbial strains that are widely used in the food fermentation industry are mostly LAB . Their centation . Due to atus yet , since tatus yet .Foods containing an active live population of probiotics along with prebiotics are categorized as functional foods and have gained extensive popularity and acceptance in the health sector .Global consumers have become aware of the importance of consuming a healthy diet to improve their health and sustain the quality of their lives . SelecteThrough the consumption of functional food, probiotics stimulate a microbial balance in the gastrointestinal tract of the host. Extensive studies have established the beneficial effects of probiotics in the prevention of intestinal disorders, the protection against cancer, the activation of the immune function, the reduction of symptoms of irritable bowel syndrome (IBS), the lowering of cholesterol level, and in other processes, as summarized in An active probiotic microbiota exerts several biological effects through diverse mechanisms. For example, for their survival in the GIT, they compete for nutrients and by doing so they prevent pathogenic microorganisms from adhering to the epithelial cells in the GIT. Secondarily, LAB produce antagonistic compounds like short-chain fatty acids (SCFA), bacteriocins, and organic acids, that inhibit pathogens’ growth and hinder the colonization of opportunistic microorganisms. Other health-promoting activities exerted by LAB are the regulation of the immune system by the stimulation of immunoglobulin production, the increase in the cytotoxicity of natural killer cells, and the modulation of cytokine secretion . TherefoLAB have been used as live cultures in artisanal food fermentation for a long time. They have been extensively used in the food industry as starter cultures due to the several desired characteristics linked to their metabolic activities that they impart to the final food products . Their sA healthier version of “sourdough” bread has gained consumers’ interest. It is a slow-fermented bread prepared by a combination of LAB and yeast cultures. This bread is different from common bread because a live culture is used as a sourdough starter, which acts as a natural leavening agent. From a health perspective, this special bread has several properties compared to unfermented supermarket loaves. The naturally produced acids during slow and long fermentations help to break down the gluten present in the flour. This process makes this sourdough bread more digestible and easier for the body to absorb compared to unfermented normal bread ,31. ProbClostridium spp. remain one of the main concerns causing economic, nutritional, and microbiological problems in the dairy industry. Clostridium sporogenes and Cl. tepidium strains with late blowing characteristics were detected in traditional cheese samples. They cause the swelling of cheese during aging. This phenomenon often affects hard-pressed cheeses and usually occurs from a few weeks to months of the aging process. Traditional Swiss-style cheeses are essentially meant to undergo late-blowing. This effect can be caused by several types of bacteria that are able to consume lactose, lactic acid, and remaining nutrient, and produce many different byproducts, including CO2, which causes gas bubble formation and holes in the mass of the cheese. Butyric acid fermentation is one of the frequent defects of hard or semi-hard cheeses, causing safety and economic problems [Clostridium is an anaerobic Gram-positive spore-forming and gas-producing bacterium that is considered as the main agent causing late-blowing in cheeses [Clostridium spp. in a variety of Turkish Kashar cheese, LAB strains were tested for their anti-clostridial activity. L. plantarum Y48 and Lc. lactis subsp. lactis PY91K were found to be effective in in vitro experiments, and then their dual effect as adjunct cultures was tested for the inhibition of Clostridium spp. in the production of Kashar cheese to prevent the undesirable late-blowing effect [LAB have also proved their activity to control food-spoiling microorganisms. problems . Clostri cheeses . To contg effect .LAB have proved their ability to synthesize many metabolites with pharmaceutical properties beneficial to health ,40,41. TThe antimicrobial properties of probiotic cultures may be due to their competition with foodborne pathogens for scavenging nutrients for their colonization in the GIT of the host. A variety of important compounds that they produce, such as organic acids , hydrogen peroxide, exopolysaccharides, bacteriocins, and similar inhibitory substances, possess antagonistic activity against many undesirable and pathogenic microorganisms . BacteriThe disturbance of healthy gut microbes is a common condition due to the short- or long-term usage of antibiotics by patients. In such cases, the diets of patients after a prescribed course of antibiotics can be supplemented with probiotics . Some poLactobacillus paracasei subsp. paracasei BGSJ2-8 was studied for its adhesion to intestinal epithelial cells and was shown to help decrease Escherichia coli’s association with Caco-2 cells. Researchers reported the presence of EPS on the surface of Lactobacilli could enhance the communication between bacterial cells and the intestinal epithelium, through the adhesion of probiotic cells necessary for their gut colonization [S-layer proteins (isolated from Lactobacillus helveticus) significantly enhanced the adhesion of liposomes to the GIT [Lactobacillus cultured in milk supplemented with lactophospholipin could boost the adhesion of Lactobacillus to Caco-2 cells. This biochemical activity required the expression of the genes EF-TU and Cnb related to lactobacillus adhesion [A few studies have confirmed that some organic compounds and functional natural ingredients can specifically improve the adhesion of bacterial strains or stimulate the expression of intestinal cell adhesion proteins. The contribution of exopolysaccharide (EPS) secreted by a LAB strain isolated from dairy nization . Wang et the GIT . A reporadhesion .Lactobacillus plantarum is a lactic acid bacterium found in animal and human mucosae, as well as in the nutritive-rich environments of several fermented food items [od items . EPS areod items . In addiod items . EPS areod items .The health benefits offered by LAB are also nutritionally-therapeutic and include their role in vitamin production, allergies, and immunoregulation , the relAntibiotic therapy is a common practice for the treatment of microbial infections, but as a result, the gut microbiota is disturbed, and in some patients this causes the initiation of diarrhea. Consumption of probiotic fermented foods with live LAB or commercially available probiotic preparations may prevent gastrointestinal disruption during and after antibiotic therapy by helping to re-establish the normal microbiota of the intestine ,58,59.Lactobacillus gasseri has been reported to exert anti-inflammatory effects in mouse colitis models, where it was able to maintain the integrity of the gut barrier. Hence, results suggested the protective role of this strain of probiotic against the progression of inflammatory intestinal diseases, such as IBD [The disruption in GIT microbiome also disrupts the physical and microbial barriers of the intestine, which affects the intestinal permeability and, in due course, may favor inflammation and systemic diseases . IBD is h as IBD .L. plantarum, and observations showed their effectiveness in enhancing the adhesion rate of L. paracasei cells to Caco-2 cells. Researchers claimed that previous works indicated that only a small number of prebiotics act as connectors between probiotics and GIT cells in the host, whereas most prebiotics do not influence the adhesion of probiotics [Studies have confirmed that EPS secreted by LAB have exclusive properties in modifying the gut microbiota . EPS alsobiotics ,66,67. Robiotics .Lipopolysaccharides (LPS), also often called endotoxins, are lipid-soluble outer-membrane components mainly secreted by Gram-negative bacteria. LPS levels have been found to be significantly increased in many studies of inflammatory diseases and diabetes ,70,71. LLactobacillus plantarum on the adhesion of cells of another LAB, Lactobacillus paracasei, was studied [The gut microbiota has also been indicated to be associated with the development of diabetes, probably through its role in regulating the immune response, because the abundance and composition of the gut microbiota vary with the quality of diet and imbalanced nutrition. Because of their exceptional advantages, probiotics have been extensively studied in T2D disease models. Disturbances in the gut microbiota can aggravate Type 2 Diabetes (T2D); however, the gut microbiota could also be affected in a patient with T2D. In a recently published report, the effect of exopolysaccharides synthesized by a strain of probiotic bacteria  studied .L. plantarum was used in in vivo experiments. The results showed the adhesion of L. paracasei cells to Caco-2 cells was two-fold, and thereby, the cells of L. paracasei could maintain their propagation. The change in intestinal microbiota due to L. plantarum activities was beneficial in supporting the balance of desired strains of Bifidobacterium and Faecalibaculum. Additionally, their activities inhibited the colonization of other strains of bacteria involved in energy metabolism, such as Muribaculaceae, Firmicutes, and Lachnospiraceae. Researchers indicated that the correction in the microbiota improved the intestinal barrier, which was essential for the secretion of the gut hormones peptide YY and glucagon-like peptide-1 [EPS produced by eptide-1 .A report by Zhao et al.  indicateKluyveromyces marxianus and Saccharomyces cerevisiae var. boulardii have been reported to act as cancer chemo-preventive and antiproliferative and showed superoxide anion scavenging properties [With a better awareness of the role of the microbiome in the pathogenesis of cancer, the potential of microbiota-based therapeutics has become an increasingly researched topic in the treatment of cancer. Probiotics are microorganisms providing health benefits to the host by restoring or improving the gut microbiota when they are consumed in the required amount . They exoperties . Probiotoperties . It is woperties ,88.Bacteroides massiliensis was detected in samples of patients suffering from prostate cancer, suggesting the potential role of these bacteria in the expansion of prostate cancer [Bacteroides fragilis toxin was shown to activate a pro-carcinogenic inflammatory pathway in colonic epithelial cells. The gut microbiome has also been shown to be involved in the carcinogenesis of colorectal cancer, with Bacteroides fragilis, Fusobacterium nucleatum, and Peptostreptococcus anaerobius being highlighted as potential players in its development [F. nucleatum-positive colorectal cancer, suggesting that the intestinal microbiome could be an important mediator in the interaction of diet and colorectal cancer [A high number of e cancer . In a ste cancer , a Bacteelopment . A diet l cancer ,93.Saccharomyces boulardii, a variety of S. cerevisiae, is used as a probiotic yeast in the food and drug industries. However, S. boulardii is an opportunistic pathogen, but the culture supernatant of S. boulardii contains different compounds with health benefits and without pathogenic and toxicity activities. The supernatant of this organism has been recommended for its health-promoting benefits. S. boulardii is commonly used as a therapeutic agent to prevent or treat diarrhea and other GI disorders in neonates and adults occasionally [S. boulardii supernatant (SBS) on cell viability have been described, with the induction of apoptosis and the suppression of survivin gene expression in MCF-7 and MCF-7/MX cells,non-drug-resistant and multidrug-resistant breast cancer cells, respectively. SBS is suggested as a prospective anticancer drug to be administered in addition to standard treatments like surgery and chemotherapy to treat human breast carcinoma [sionally . The effarcinoma . The oveEscherichia coli Nissle 1917 is well studied as a versatile probiotic strain and has a long track record of safety in humans. Therefore, it has been used as a popular starting point for engineered therapeutic microbe efforts because of its compatibility with canonical genetic engineering techniques for bacteria [E. coli Nissle 1917 as a cellular chassis for probiotic-associated therapeutic curli hybrids. Engineered E. coli Nissle 1917 was used for the delivery of matrix-tethered therapeutic domains to the gut [bacteria . This stbacteria . Studiesbacteria . Researc the gut .Clostridioides difficile infection causing acute diarrhea, where there is the concern that introducing probiotics using this process will delay the return to a normal microbiota. FMT has been widely accepted as an attempt to establish the microbiome’s pivotal role in gut dysbiosis-related disease models and as a new disease-altering therapy. Regardless of the potential beneficial results of FMT reported in various disease models, there is a discrepancy in the procedural agreement for performing FMT reported by different research groups. Even though there are many studies using FMT to test the causal links between the microbiome and diseases, a large number of variables of FMT procedures differ between studies, and there is no scientific agreement on a standard methodology [In this review, all cited published work mainly deals with scientific data on the influence of diets and supplements in controlling and restoring the disturbed gut microbiota and, consequently, its therapeutic effect. The introduction of probiotic bacteria in the GIT through the consumption of fermented food and drinks, as a source of nutrients and probiotics, is not expected to cause disturbances in the normal microbiota. We have not discussed Fecal Microbiota Transplantation (FMT), the process of transferring fecal bacteria and other microbes from a healthy individual into a sick individual. FMT has been suggested as an effective treatment for hodology .In the last few decades, there has been a rise in the number of studies on the gut microbiome, and the focus of research has begun to move towards clinical and therapeutic studies to understand how the microbiome can influence human health and be effective in the alleviation of several diseases . Neverth


Child health services remain one of the most cost-effective strategies in reducing child mortality which is still disturbingly high in sub-Saharan Africa (SSA). Efforts by governments and other stakeholders in response to the COVID-19 pandemic have inadvertently disrupted the provision of other essential health services including those focusing on children. This comes at the backdrop of the World Health Organization´s guidelines for countries to sustain priority services while fighting the COVID-19 pandemic. Underpinned by the Socio-Ecological Model (SEM), we propose population-based interventions which could help in sustaining child health services in the midst of COVID-19 in SSA. At the intrapersonal and interpersonal levels, educating mothers during routine community outreach services, during child welfare clinics, and in church/mosques could be useful. Education and sensitization of male partners could also be an important intervention. At the institutional and community levels, we recommend the allocation of more funds to other essential health services including child health services. The training and deployment of more general nurses, community health nurses/officers, and public health officers is imperative. The provision and adherence to COVID-19 preventive protocols at health facilities are also recommended at these levels. At the public policy level, insurance and tax relief packages for frontline professionals providing child health services and micro-credit facilities at reduced interest rates for women could be implemented towards sustaining the utilisation of child health services. It is, rch 2020 . The modIndividual and Interpersonal levels: these levels of the SEM comprise the individual and those they have direct contacts with such as family, close friends, neighbourhood, work, school, church, and neighbourhood [bourhood . With thbourhood . Other cInstitutional and community levels: the institutional and community levels of the SEM include societal, religious, and cultural values and influences [fluences . These lfluences . As resufluences . The panWhile the primary effects of the pandemic on children appear to be limited, children are highly susceptible to the indirect secondary effects of the pandemic. The preventive measures such as lockdowns, social distancing, the conversion of facilities into COVID-19 treatment and isolation centres, diversion of limited resources for COVID-19 management, reassignment of health professionals for the management of the pandemic have led to a reduction in the utilisation of basic child health services such as immunization . The panPublic policy level: this level of the SEM includes the influence of public policy on child health services utilisation amidst the COVID-19 pandemic. Policy strategies implemented by nations globally to tackle COVID-19 upon its emergence were purposed at providing adequate care for all patients while minimizing the effects of the pandemic on other health services including child health services . GovernmSustaining child health services is very crucial for SSA countries in reducing child mortality levels to as low as 25 per 1,000 live births by the year 2030. While SSA countries are putting all essential measures in place to fight COVID-19, effort should also be made to sustain child health services utilisation. At the intrapersonal and interpersonal levels, educating mothers during routine community outreach services, during child welfare clinics, and in church/mosques could be useful. Education and sensitization of male partners could also be an important intervention. At the institutional and community levels, we recommend the allocation of more funds to other essential health services including child health services. The training and deployment of more general nurses, community health nurses/officers, and public health officers is an imperative. The provision and adherence to COVID-19 preventive protocols at health facilities are also recommended at these levels. At the public policy level, insurance and tax relief packages for frontline professionals providing child health services and micro-credit facilities at reduced interest rates for women could be implemented towards sustaining the utilisation of child health services.


Brain damage as a result of ischemic stroke and trauma, following injury, or in neurodegenerative disease generates severe consequences leading to impairments in motor and cognitive functions. Although neuroplasticity persists in the adult human brain, the reorganization and self-repair are limited and recovery from most diseases is far from certain. Recent discoveries point to repair strategies of the adult injured or diseased human brain that require approaches targeting neuron replacement, angiogenesis, gliogenesis, and enhancing synaptic plasticity. To achieve an efficient regenerative response, the orchestration of scar formation, cleaning debris of damaged cells and integrating newborn neurons into existing circuitries is of importance. Knowledge of the various steps and the underlying neurochemical processes supporting cell genesis and integration, provides valuable insights of signaling pathway management that might lead to new therapeutic strategies in tissue repair.Chiareli et al.) and their reprograming potential following spinal cord injury  or cortical brain damage . Thereby, two articles highlight the reprogramming capacity of reactive astrocytes in vitro that involves Galectin-3 triggering of Notch1 signaling in response to damage-facilitating nuclear translocation of Notch intracellular domain . Excitingly, Puls et al. reveal an in vivo astrocyte-to-neuron conversion, whereby reactive astrocytes covert into functional neurons via the NeuroD1 pathway that may improve neurorepair processes following spinal cord injury.For this special issue, we collected review articles and original research reports summarizing and discussing repair strategies for the rodent and human brain. The studies specifically focus on glial cells in the repair process, and examine the new exciting role of astrocytes .Besides astrocytes, gliogenesis of microglia and oligodendrocyte precursor cells (OPCs) in the adult brain promote repair processes and enhance signaling pathways that in turn contribute to neuroplasticity. Specifically, Neuron-Glia (NG) 2-positive OPCs constitute the main proliferating cell population outside the neurogenic niches, and display an endogenous source with multipotent potential. Importantly, demyelinating diseases require oligodendrocytes; and the review by Turkin et al.). Apolipoprotein E (APOE) is an important factor in the brain vasculature and also associated with an increased risk to develop AD by affecting cerebral vascular integrity, brain metabolism, synaptic plasticity, and neuroinflammation. In this issue, two studies present their findings and discuss the autocrine functions of apoE genotype in the modulation of basal phenotypic state of brain endothelial cells, the role of APOE4 in increased inflammation , and in promoting tonic-clonic seizures .Microglia take part in neuroplasticity of the healthy rodent hippocampus and may be a potential therapeutic model in the maintenance of mood. In pathology, dysfunctional microglia contribute to late-stage development of Alzheimer's Disease (AD) inducing cell death and the release of brain-derived neurotrophic factor  bioscaffolds and the creation of cell platforms providing the basis for tissue engineering .The review by In conclusion, the present collection of articles reflects the complexity of the central nervous system and thus the varies repair strategies and mechanisms involved in the neurorepair process. Collectively, our studies provide an overview and explore different strategic approaches including gliogenesis, angiogenesis, neurogenesis, and targeting synaptic plasticity following distinct types of brain damage. Our approach in summarizing the specific findings in this edition is to encourage new young scientists to discover novel pathways, to inspire researchers to go new innovative ways—facilitating neurorepair process and leading to the development of novel solutions that improve the quality of life of patients following injury and in neurological disease.FK, FS, and MP have made a substantial, direct and intellectual contribution to this editorial, and all authors have approved it for publication.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


The COVID-19 pandemic impacted meat production, supply chain, and meat prices that caused a severe socio-economic crisis worldwide. Initially, meat and meat products' prices increased due to less production and increased demand because of panic buying. Whereas, later on, both meat production and demand were significantly decreased due to lockdown restrictions and lower purchasing power of the consumers that results in a decrease in meat prices. In early April 2020, meat packing facilities started to shut down due to the rapid spread of the COVID-19 virus among workers. Furthermore, meat producers and processors faced difficulty in harvesting and shipment of the products due to lockdown situations, decrease in labor force, restrictions in movement of animals within and across the country and change in legislation of local and international export market. These conditions adversely impacted the meat industry due to decrease in meat production, processing and distribution facilities. It is suggested that the integration among all the meat industry stakeholders is quite essential for the sustainability of the industry's supply chain to cope with such devastating conditions the future may hold. This review aimed to discuss different aspects of the meat industry and supply chain during the COVID-19 pandemic and proposed some future directions. The COVID-19 pandemic adversely affected many sectors of life, taking a huge toll not only on the economy but the livestock industry, such as global meat production and supply chain. Several countries' preventive measures included travel restrictions, border controls, and country lockdowns, developed harsh consequences affecting production and supply chain. Meat production and processing were compromised due to difficulty of purchasing production inputs such as feed for animals, restrictions of transportation of live animals including seasonal border crossing restrictions, accessing professional services and workforce, and restrictions in supplying meat and meat products to the markets . These pThe COVID-19 virus rapidly spread among meat plant workers due to prolonged contact with infected co-workers, inability to follow social distancing at the workplace, shared working areas, and common transportation methods to and from work. These infected workers caused the spread of illness at community levels . TherefoThe prices of meat and meat products also fluctuated due to a gap in demand and supply, mainly due to panic buying and lockdown restrictions. Therefore, this review aimed to highlight the impact of COVID-19 on meat production, supply chain, and price fluctuations. This will be helpful to formulate future recommendations to ensure a stable meat supply chain. It will also help livestock farmers, animal health professionals, slaughterhouse workers, meat processors, traders, and policymakers to effectively combat worse situations in the future.The SARS-CoV-2 is a newly identified virus that caused the outbreak of pneumonia in Wuhan, China, in December 2019. Within no time, SARS-CoV-2 was isolated on January 7, 2020, and complete sequencing was performed. Initially, the World Health Organization (WHO) named the coronavirus as the 2019-novel coronavirus (COVID-19) on January 12, 2020. It was reported that the genome sequence of COVID-19 is quite similar to a bat CoV RaTG13 and has 96.2% identity and 79.5% similarity to SARS-CoV as well. After studying the genome sequence results and evolutionary analysis, bats were assumed to be the virus's natural hosts. Additionally, it was also assumed that SARS CoV-2 might be transmitted from bats via unknown intermediate hosts and finally infecting the human race . The closure of the educational institutes and restaurants showed an adverse effect on the supply and distribution of meat and its products . FurtherThe pandemic outbreak also interrupted the routine life of the people. Staying at home for longer durations resulted in higher consumptions of carbohydrates, fat, and proteins. The stress of quarantine measures pushed the people toward using more sugar-based diets for feeling motivated and positive because the food items increase the production of serotonin to combat stress . The demConsumers also started to stock items that have longer shelf life during COVID-19. They also experienced the reduced availability of certain types of food items. In European countries, flour is the product that attained more attention due to home-cooking, which lead to its shortage in the market during the initial few months of the pandemic. The prices of the staple items were also increased due to the panic buying. Consumers preferred take-out or home delivery options rather than having a meal in restaurants due to lockdowns . ConsumeThe meat products prices increased due to demand and supply issues; panic buying resulted in empty shelves. The producers were unable to supply enough products due to the closure of meat processing plants . Akter  presenteIn a recent study , highligIn contrast , reporteThe rapidly evolving nature of the COVID-19 virus created many problems for the meat industry. The limitations on animal exportation, logistics restrictions, and the shutting down of slaughterhouses, restaurants, and food services adversely affected all stages of the meat supply chain. Farmers were unable to find a suitable market to sell their live animals. Meat processing capacity also decreased due to the closure of the processing plants. The availability of meat and its products for the consumers was also compromised due to plant closures and panic buying, resulting in fluctuations in prices. Therefore, the following suggestions are proposed to maintain the different stages of the supply chain in order to combat such drastic situations in the future:In the future, the following precautionary measures and practical recommendations should be followed to reduce the impact of such devastating pandemic situations and ensure continuity of meat production and supply chain: (1) livestock farmers should (i) communicate with suppliers of consumables, feed distributors and professionals such as veterinarians and meat processors to find solutions to secure inputs supply, farm services, and meat supply chain; (ii) talk with farmers associations to reach out the policymakers for getting the compulsory exemptions for transportation of feed, animals, and personnel; (ii) adopt strict precautionary and management measures at farms to avoid disease spread. (2) Professionals should (i) secure continuous services at farms to ensure animal health; (ii) up to date with the knowledge about the pandemic and aid farmers to ensure farm biosecurity. (3) Meat processors should (i) adopt online business models for a continuous supply of meat under such conditions; (ii) introduce modern automation at the plant to reduce labor involvement for sustainable meat production. (4) Policymakers should (i) develop the policies to reduce the effect of such pandemic on meat production and supply chain; (ii) communicate with the government to ensure continuous normal flow of inputs and outputs of the meat production system; (iii) review the existing animal disease prevention and control policies; (iv) take steps to control the food and meat prices in the market; (v) communicate with across the border governments to facilitate the controlled transportation or import and export of animals and farm inputs. (5) Meat scientists should look forward to developing cultured meat and plant-based alternatives to overcome food insecurity under such worst situations.MI compiled the review materials, drafted the manuscript, contributed to the abstract, introduction, conclusions, future recommendations and involved in the review, and editing of the manuscript. MY contributed to the impacts of COVID-19 on meat supply chains, changes in consumer behavior, and contributed to review and editing of the manuscript. IB contributed to impact of COVID-19 on overall meat production and contributed to review and editing of the manuscript. SA contributed to the illness among workers, meat plant as hotspot, and contributed to review and editing of the manuscript. MSI wrote the meat price fluctuations, and contributed to review and editing of the manuscript. MJ and ZH involved in writing-review of the first draft and contributed in revision of the manuscript. AS contributed to shutdowns of meat plants, concerns of farmers and processors, and contributed to review and editing of the manuscript. SU contributed to the origin of COVID-19 and contributed to review and editing of the manuscript. DG-R helped to improve the grammar, sentence structures of the manuscript, and contributed to review and editing of the manuscript. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Vaccine acceptance and hesitancy among the general population and health care workers play an important role in successfully controlling the Coronavirus Disease (COVID)-19 pandemic. While there is evidence for vaccine hesitancy across the globe, wide variation in factors influencing vaccine acceptance has been reported, mainly from High-Income Countries (HIC). However, the evidence from Low- and Middle-Income Countries (LMICs) remains unclear. The objective of this review was to describe the determinants of vaccine acceptance and strategies to address those in an LMIC context.The World Health Organization’s (WHO) Measuring Behavioral and Social Drivers of Vaccination (BeSD) Increasing Vaccination Model was employed to identify factors that influenced vaccine acceptance. All evidence related to supply-side and demand-side determinants and social and health system processes were examined. A comprehensive search for published literature was conducted in three databases and grey literature in relevant websites of government, multinational agencies, and COVID-19 resource aggregators, followed by a narrative synthesis.Overall, the results showed that the vaccine acceptance rates differed across LMICs, with a wide variety of reasons cited for vaccine hesitancy. Vaccine acceptance was reportedly greater among males, those with higher education, elevated socio-economic status, the unmarried, those employed as health care workers. Evidence suggested that exposure to misinformation about COVID-19 vaccines and public concerns over the safety of vaccines may contribute to lower acceptance rates. Strategies to increase vaccine acceptance rates included direct engagement with communities through influencers, including community leaders and health experts; clear and transparent communication about COVID-19 vaccines, financial and non-financial incentives; and strong endorsement from health care workers. Trust in government was identified as a significant enabler of vaccine acceptance.There is a need for measures to address public acceptability, trust and concern over the safety and benefit of approved vaccines. Local context is essential to consider while developing programs to promote vaccine uptake. The governments worldwide also need to strategize to develop plans to address the anxiety and vaccine related concerns of community regarding vaccine hesitancy. There is a need for further research to evaluate strategies to address vaccine hesitancy in LMIC. The COVID-19 pandemic has caused significant morbidity and mortality globally, with more than 3 million deaths reported worldwide as of May 2021 .The success of the COVID-19 vaccination programme will depend on the proportion of the population willing to be vaccinated, and recent estimates suggest that up to 70% of the population may require vaccination to bring an end to the current pandemic . Thus, hVaccine hesitancy has been reported in a few surveys, although the prevalence of this phenomenon remains to be rigorously studied in LMIC -8,13,14.The Rapid Evidence Synthesis team at the George Institute for Global Health (TGI), India, and the Knowledge Management Division (KMD) of the National Health Systems Resource Centre (NHSRC), India, collaborated to identify evidence on; i) the determinants of vaccine acceptance and hesitancy, and ii) interventions that can promote vaccine acceptance. Additionally, the team reviewed relevant literature that contextualises evidence relevant to LMIC context.An initial scoping of the literature was conducted. Following this, the World Health Organization’s (WHO’s) Measuring Behavioral and Social Drivers of Vaccination (BeSD) Increasing Vaccination Model  independently at the title and abstract screening stage in Rayyan database , and at the full text screening stage. Disagreements on inclusion and exclusion of studies were resolved by consensus between the two reviewers or in consultation with a third reviewer. Multiple types and levels of evidence were considered to inform decision making to plan and develop resources for COVID-19 vaccine acceptance and uptake.A pre-designed data extraction template was used, and a narrative synthesis was undertaken for the findings of the review. Data were extracted by an independent reviewer  using a predesigned data extraction form and an experienced reviewer  assessed the correctness of the data by selecting 25% of the studies randomly. Relevant data on country/region, sample characteristics, study designs, determinants, strategies, and results were extracted. The evidence was structured and organised by sections corresponding to the study framework. Details on search strategies and a list of websites searched are provided in Appendix S1 and S2 in the https://www.medrxiv.org/) relevant to the LMIC context, however, these were not included as these were not peer-reviewed and therefore, could not be used to inform or guide decision-making. However, a brief summary of the studies relevant to the LMIC context has been provided . Existing diagnostic and outreach facilities may be utilised for vaccine registration. Other strategies may include clear, consistent, and transparent communication regarding service availability, risks, and benefits of vaccines through general and intensive campaigns ,20,28. MOur review has some limitations. Studies retrieved from electronic databases may not provide current public opinions due to the journal publication process. However, this approach was undertaken to provide a concise summary of the evidence on COVID-19 vaccine hesitancy in the LMIC context within a short timeframe. Due to the rapid nature of the review, the inclusion of studies may not be exhaustive. The methodological quality of the included studies was not evaluated, which may have impacted the reliability of the conclusions. The included studies mainly were cross-sectional surveys that provided snapshots of vaccine hesitancy in different LMICs, which also showed that different approaches were used to evaluate the willingness to accept COVID-19 vaccines in multiple studies. Some surveys used a Likert scale and some binary response of yes/No. An in-depth comparison of differences in vaccine acceptance rates and the reasons for them between different studies was not done and can be considered as one of the limitations.However, despite the limitations of the review, the consistency of the findings from the included studies provides an understanding of COVID-19 vaccine acceptance and hesitancy across different regions in LMIC. There is a lack of evidence on formal evaluation of strategies to address vaccine acceptance and hesitancy. There is a need to test strategies using pre-and post-test studies to address vaccine hesitancy and increase vaccine uptake in LMICs.This rapid review contributes to the evidence base for vaccine acceptance and hesitancy, with some policy implications for the LMIC context. Decision-makers should consider determinants for reluctance in the relevant context and tailor appropriate and feasible solutions to the target population. Studies suggest high acceptance for the most part; localised strategies to address concerns and misinformation are required to engage the community and are based on broader trust-building and vaccine delivery system-strengthening activities. Further inquiry into best practices for this and adaptation of known strategies and approaches from different LMICs are recommended.


South Africa became one of the first African countries to receive the COVID-19 vaccine. As the rest of Africa prepares to receive COVID-19 vaccines, most countries in Africa have set up national-level coordination committees for developing national vaccination deployment plans. While the main focus of these committees has been on setting up strategies that facilitate the swift distribution of COVID-19 vaccines once they are available, the role of effective public health awareness should not be ignored. Countries must devise strategies on how best to enhance public understanding and curb misinformation about the vaccines. With this viewpoint, we unpack the threat of COVID-19 vaccine hesitancy and offer recommendations for COVID-19 vaccine communication strategies in the South African and Zimbabwean contexts. In December 2019, a pneumonia-like illness of unknown origin was detected in Wuhan, China. The causative agent was identified and named severe respiratory coronavirus 2 (SARS-CoV 2) by early February 2020 , airbornIn Sub-Saharan Africa, COVID-19 has resulted in additional pressure to already strained health systems characterized by poor health outcomes with high mortality rates linked to a triple burden of disease  . In an eVaccination has been reported as one of the top notable public health achievements to have occurred during the 1900s. Vaccination has resulted in the eradication of smallpox and control of poliomyelitis, measles, rubella, tetanus, diphtheria, and other infectious diseases . DespiteThere has been global competition to procure COVID-19 vaccines, and African countries have been substantially less successful than richer countries in securing supplies. According to the Secretary General of the United Nations, 75% of all COVID-19 vaccines have been administered in just 10 countries . AccordiMost African countries are expecting to obtain the COVID-19 vaccine through the COVAX facility. COVAX was launched in April 2020 by the World Health Organization, the European Commission, and France as a global response strategy to the COVID-19 pandemic . COVAX wOn 1 February 2021, South Africa became one of the first African countries to receive a COVID-19 vaccine. The country received a million doses of the AstraZeneca/Oxford COVID-19 vaccine, produced by AstraZeneca-SK Bioscience (AZ-SKBio) and the Serum Institute of India (AZ-SII) . The rolZimbabwe received its first delivery of a COVID-19 vaccine on the 15th of February 2021 with the roll-out of the vaccination program beginning 18th February 2021 . At the Herd immunity, which offers some protection to unvaccinated individuals, is compromised when widespread vaccine acceptance is not achieved, and disease outbreaks result . More thSeveral communities in Africa have always resisted vaccines, irrespective of the type and form of vaccination. For instance, in Zimbabwe, the Apostolic Faith community religious group, which makes up a third of the population, is historically known to have poor health-seeking behavior, including vaccine uptake ,37,38. RThe halt in South Africa’s roll out of the AstraZeneca/Oxford vaccine described above  may furtThe sources of health- and vaccination-related information play vital roles in the choices people make about vaccinations, with current research pointing to information overload , misinfoThe ongoing global discussion on treatment options for COVID-19 may potentially leave communities undecided on whether to trust the treatment option versus the vaccination option. In Zimbabwe, debate among scientists and researchers has been raging recently about the efficacy of ivermectin in the treatment of COVID-19. Some medical doctors have been widely advocating for its use. This discussion has the potential to swerve communities towards the treatment options versus vaccines. In South Africa, some health workers have started to question the efficacy of the COVID-19 vaccine . SimilarAs noted by polio vaccination hesitancy research in northern Nigerian states, failure by the governments to deliver on key areas of their mandate such as security, water, sanitation, and food security may breed mistrust in other areas such as vaccines ,50. In tThe threat of vaccine hesitancy is not restricted to our study context alone . In FranMapping the journey that each individual or communities goes through in their quest to seek good health is important in improving community preparedness and addressing fears towards the COVID-19 vaccine. By looking at the lives of specific target groups and following their health-seeking behavior, policy makers will be able to tailor messaging to meet the needs of each target audience . ContinuThe low effect at a personal level of COVID-19 in its first wave in Africa contributed to a widespread belief that COVID-19 is overwhelmingly not an African problem . HoweverA strong healthcare brand position communicates the brand’s value position with consistency, clarity, conviction, and credibility in a way that has meaning for consumers and is unmatched by others . Clear pThe second wave of COVID-19 has seen Zimbabwe go through another intense total lockdown, with a ban on all informal trade, in a country where a large proportion of the population largely lives from “hand to mouth”. In this instance, the COVID-19 vaccine should be positioned as an opportunity that can enable small to medium traders to get their lives back and once again trade as normal. Correctly positioning the emotional and immediate economic benefits of the COVID-19 vaccine to the individual will likely sway their acceptance of the vaccine.An analogy can be made withthe Voluntary Medical Male Circumcision program in Zimbabwe where initially the intervention was positioned as a medical program that would help reduce the chances of men contracting HIV by 60% . DespiteConducting social “market” research will allow the unearthing of critical issues such as underlying barriers and facilitators for COVID-19 vaccine compliance in the target group. Social “market” research goes beyond the traditional demographic methods of segmenting audiences, and digs deeper into the psychographic issues, enabling comprehensive segmenting of the audience members and instituting appropriate and targeted messaging and interventions for each segment. This research into COVID-19 vaccine attitudes in the two countries can help design communications and enhance understanding of the target audience’s characteristics, attitudes, beliefs, values, behaviors, and determinants, benefits, and barriers to behavior.Most countries in Africa have set up national-level coordination committees for developing national vaccination deployment plans. While the main focus of these committees has been on setting up strategies that facilitate the swift distribution of COVID-19 vaccines once they are available, the role of public health awareness should not be ignored.For COVID-19 vaccine communication strategies, firstly, we recommend joint efforts between government agencies and civil society to reach the communities. Civil society Organizations (CSOs) have historically been pivotal in mobilizing the support of the public through working directly with vulnerable populations and the invaluable access and reach they have, particularly to some of the hard-to-reach communities, whether they are in remote rural villages or urban settings. Further, CSOs will play an important role because of their ability to establish trust at the grassroots level, with communities, families, and individuals . When enSecondly, governments should utilize popular online social media platforms, such as WhatsApp and Twitter, to raise public awareness of the benefits of the COVID-19 vaccine. Whilst social media is dominant in certain population groups, it is imperative to note that different audiences have varied preferences for receiving credible information about personal health. Therefore, the development of public health campaign materials specifically tailored to social media platforms and their users while increasing the use of emotive language and imagery that is common to social media may also help raise COVID-19 vaccine awareness . To furtThirdly, traditional media platforms will play a key role in public approval of the COVID-19 vaccinations. Traditional media includes television, radio, newspapers, magazines, medical journals, books, and pamphlets. This type of media and mass communication was available before the advent of digital media and still has substantial value in reaching the population in both South Africa and Zimbabwe. The impact of how the media constructs and frames messages about vaccination programs has been well elaborated elsewhere . We callFourthly, the engagement of popular, influential individuals in society, such as musicians and/or the clergy, should also be explored ,67,68. ZFinally, building on already existing channels, communication strategies should engage representatives of community groups affected by COVID-19. In this way, all stakeholders would have clear guidelines to communicate scientifically sound messages to the public, communicated in simplified language easily understood by the communities. The engagement of representatives of community groups would also allow for feedback mechanisms for the acknowledgement of community efforts in previous health interventions  to encouFor COVID-19 vaccination in South Africa and Zimbabwe to be successful, approximately 65–80% of each country’s population has to be vaccinated to achieve herd immunity. The threat of vaccine hesitancy cannot be ignored. The factors contributing to vaccine hesitancy in the two countries are multifaceted and thus require equally complex strategies to be addressed. We note that community vaccine hesitancy should be understood and respected. The strategies to overcome it must be guided by the provision of sufficient information using the correct message delivery approaches to the community to allay any concerns they may have regarding the vaccines. The public needs to be aware of all issues concerning COVID-19 vaccines to have the confidence that they are safe. COVID-19 vaccine roll-out programs must be done in a manner that encourages discussions with and engagement of all stakeholders to address and ensure that communities get the correct information to make the correct decision. The national COVID-19 vaccination programs of both South Africa and Zimbabwe could benefit from champions such as artists, politicians, and religious leaders providing the correct information to raise community awareness and ensure vaccine acceptance.The views expressed in this piece are of the authors and do not reflect the official positions of their institutions.