Isolation and identification of potential probiotic Lactobacillus species from feces of infants in southwest Iran.
OBJECTIVES
To evaluate the potential probiotic properties of Lactobacillus strains isolated from feces of infants and also to determine their antimicrobial activity against some enteropathogenic bacteria.


METHODS
The Fecal samples were prepared from 120 infants aged less than 24 months. In total, 105 Lactobacillus strains were identified by phenotypic tests. Thirty isolates were randomly selected to study their potential probiotic properties. These isolates were examined for resistance to acid (pH: 2.5, 2 h) and bile (oxgall 0.3%, 8 h), adhesion to HT-29 cells, antibiotic susceptibility, and antimicrobial activities.


RESULTS
On basis of 16S rRNA sequencing, 30 isolates identified as Lactobacillus fermentum (n = 11; 36.7%), Lactobacillus plantarum (n = 9; 30%), Lactobacillus rhamnosus (n = 6; 20%), and Lactobacillus paracasei (n = 4; 13.3%). All tested strains survived at acid and bile conditions. Six Lactobacillus strains revealed high adherence to HT-29 cells. Three strains including the L. fermentum (N2, N7), and the L. plantarum (N20) showed good probiotic potential and inhibited the growth of Yersinia enterocolitica ATCC 23715, Shigella flexneri ATCC 12022, Salmonella enterica ATCC 9270, and enteropathogenic Escherichia coli (EPEC) ATCC 43887. The antibiotic resistance test showed that all the isolates were susceptible to tetracycline, and chloramphenicol.


CONCLUSIONS
Lactobacillus strains like L. fermentum (N2, N7), and the L. plantarum (N20), could be potential probiotic, but further in vitro and in vivo studies on these probiotic strains are still required.
['Jomehzadeh|Nabi|N|', 'Javaherizadeh|Hazhir|H|', 'Amin|Mansour|M|', 'Saki|Morteza|M|', 'Al-Ouqaili|Mushtak T S|MTS|', 'Hamidi|Hajar|H|', 'Seyedmahmoudi|Maryam|M|', 'Gorjian|Zahra|Z|']
D000900:Anti-Bacterial Agents D001422:Bacterial Adhesion D002675:Child, Preschool D005243:Feces D005260:Female D006801:Humans D007223:Infant D007492:Iran D007778:Lactobacillus D008297:Male D019936:Probiotics D012336:RNA, Ribosomal, 16S D015008:Yersinia enterocolitica
Probiotic Lactobacillus Enteropathogens Adhesion