A CHROMagar screening grows pink colonies. What is the recommended next step?

Prepare for the CAMLPR Microbiology Test. Utilize flashcards and engaging multiple-choice questions, each equipped with descriptions and explanations. Ready yourself for an excellent performance!

Pink colonies on a CHROMagar VRE screen point to vanC-type Enterococcus, such as E. casseliflavus or E. gallinarum, which have intrinsic vancomycin resistance but are not the same as the high-risk vanA/vanB VRE. The appropriate next step is to confirm and characterize these isolates with a vancomycin-supplemented culture and then identify the species. Streak the pink colonies onto brain heart infusion agar with vancomycin and onto a control plate. If the organism grows with vancomycin, report to the nursing floor and proceed with species differentiation. Use pigment testing to see if pigment production is present (points to E. casseliflavus); if pigment is not present, perform a rapid xylose test (a positive result supports E. gallinarum). Additional testing such as MGP helps confirm VanC-associated Enterococcus, guiding infection-control actions and avoiding unnecessary escalation for vanA/B-type VRE. Ignoring the pink colonies or treating empirically with vancomycin would be inappropriate because confirmation and accurate speciation determine the correct clinical and infection-control response.