1. Examples of changes in colony morphology that can occur with hVISA and VISA strains.
Examples of changes in colony morphology that can occur with hVISA and VISA strains. (A) Mixed-colony morphologies from a pure culture of S. aureus from a bile specimen demonstrate remarkable heterogeneity in colony size and hemolytic activity. The small colonies were VISA, while the larger colonies were VSSA. (Reprinted from reference 197 with permission.) (B) Mixed-colony pigmentation in a pure culture of S. aureus, where the yellow colonies were VISA and the gray colonies were VSSA. The different morphologies were identical by pulsed-field gel electrophoresis. (C and D) Subtle changes in colony morphology that occur in VISA strains compared to parental VSSA strains. JKD6009 (C) is a VSSA strain, and JKD6008 (D) is a VISA strain isolated from the same patient after failed vancomycin therapy. The pulsed-field gel electrophoresis patterns were also identical for JKD6008 and JKD6009.
Benjamin P. Howden et al. Clin. Microbiol. Rev. 2010; doi: /CMR