Different Vancomycin-Intermediate Staphylococcus aureus Phenotypes Selected from the Same ST100-hVISA Parental Strain.
The aim of this study is to characterize the factors related to peptidoglycan metabolism in isogenic hVISA/VISA ST100 strains. Recently, we reported the increase in IS256 transposition in invasive hVISA ST100 clinical strains isolated from the same patient (D1 and D2) before and after vancomycin treatment and two laboratory VISA mutants (D23C9 and D2P11) selected from D2 in independent experiments. High performance liquid chromatography-mass spectrometry (HPLC-MS) analysis of peptidoglycan muropeptides showed increased proportion of monomeric muropeptides and a concomitant decrease in the proportion of tetrameric muropeptide in D2 and derived mutants when compared to the original strain D1. In addition, strain D2 and its derived mutants showed an increase in cell wall thickness with increased pbp2 gene expression. The VISA phenotype was not stable in D2P11 and showed a reduced autolysis profile. On the other hand, the mutant D23C9 differentiates from D2 and D2P11 in the autolysis profile, and pbp4 transcription profile. D2-derived mutants exhibited differences in the susceptibility to other antimicrobials. Our results highlight the possibility of selection of different VISA phenotypes from a single hVISA-ST100 genetic background.
['Di Gregorio|Sabrina|S|', 'Fernandez|Silvina|S|', 'Cuirolo|Arabela|A|', 'Verlaine|Olivier|O|', 'Amoroso|Ana|A|', 'Mengin-Lecreulx|Dominique|D|', 'Famiglietti|Angela|A|', 'Joris|Bernard|B|', 'Mollerach|Marta|M|']
D000900:Anti-Bacterial Agents D001426:Bacterial Proteins D002473:Cell Wall D004251:DNA Transposable Elements D015870:Gene Expression D006801:Humans D008826:Microbial Sensitivity Tests D009154:Mutation D046915:Penicillin-Binding Proteins D010457:Peptidoglycan D010641:Phenotype D012641:Selection, Genetic D013203:Staphylococcal Infections D013211:Staphylococcus aureus D014640:Vancomycin D020713:Vancomycin Resistance
Staphylococcus aureus hVISA VISA ST100 vancomycin MRSA