s aureus visa strains  (ATCC)

Journal: Antibiotics (Basel, Switzerland)

Article Title: Detection of Vancomycin Resistance among Methicillin-Resistant Staphylococcus aureus Strains Recovered from Children with Invasive Diseases in a Reference Pediatric Hospital.

doi: 10.3390/antibiotics13040298

Figure Lengend Snippet: Figure 3. Cell wall thickness of the 3 studied strains by transmission electron microscopy. From left to right, S. aureus 1: ATCC 259213 (vancomycin-susceptible control strain); hVISA #7: strain (recovered in this study); and S. aureus 2: VISA strain Mu50 ATCC 700699 (VISA control strain). The lines indicate the sector of the cell wall that was measured, and the labels show the measurement value in nm.

Article Snippet: From left to right, S. aureus 1: ATCC 259213 (vancomycin-susceptible control strain); hVISA #7: strain (recovered in this study); and S. aureus 2: VISA strain Mu50 ATCC 700699 (VISA control strain).

Techniques: Transmission Assay, Electron Microscopy, Control

Journal: bioRxiv

Article Title: High-throughput single-cell phenotypic profiling and backtracing exposes and predicts clinically relevant subpopulations in isogenic Staphylococcus aureus communities

doi: 10.1101/2023.11.02.562170

Figure Lengend Snippet: A) Schematic overview of the CPPT setup for comparative analysis of VISA strain Mu50 and a VSSA control. Cells were labelled with Vancomycin-BFL and PI. PI (+) -cells are depicted in gray, PI (-) -cells with different degrees of Vanco-BFL-labeling are indicated in light and dark green. PI (-) -cells were sorted onto Mueller-Hinton Agar (MHA) supplemented with different concentrations of vancomycin and colony formation was observed at different time points and for individual plates by time-lapse imaging. For VISA cells growth on a 0.25x MIC plate was used for cell fate determination (growth, no growth, and colony size variant (CSV), i.e. smaller colonies) prior to phenotypic backtracing of the ancestral phenotypic signatures in the flow cytometry dot plot. B) Flow cytometry histogram showing the fluorescence signal in the FITC-A channel of unstained and Vanco-BFL-labelled VSSA (blue) and VISA cells (red) ’. C) Percentage of sorted events that gave rise to colonies on agar plates with different concentrations of vancomycin. (D) Violin plot showing the cellular Vanco-BFL signal intensity of VISA cells for the different cell fate groups determined after growth on 0.25xMIC vancomycin. The graph shows pooled events derived from 2 independent cultures (pre-sorting) with 96 sorted events each. Statistical significance testing was performed by Kruskal Wallis test in combination with Dunn’s multiple comparisons test. (E) Colony growth dynamics of sorted VISA cells in the presence (0.25xMIC) and absence of vancomycin as analyzed by time-lapse imaging analysis. Growth (Y-axis) was measured as contour size on the edge of the colony and is plotted against cultivation time. The figure was created with BioRender.

Article Snippet: Single colonies (3 biological replicates) of the vancomycin susceptible S. aureus strain ATCC 29213 and representative clinical MRSA-VISA strain Mu50 (ATCC 700699) were grown overnight in Tryptic Soy Broth (TSB) at 37°C.

Techniques: Control, Labeling, Imaging, Variant Assay, Flow Cytometry, Fluorescence, Derivative Assay