Chromagar™ requires secondary confirmation strategies to minimize false positive/negative results for detection of Staphylococcus aureus

Chromagar is a medium that is used in culture-based colonization studies of Staphylococcus aureus. We have found that S. aureus negative colonies often fit the color recommendations for S. aureus identification and can cause overestimation of colonization rates. Confirmation of suspect colonies is important to minimize false negative/positive results.