Staphylococcus aureus is a major pathogenic bacterium found in clinical specimens and in food industry products. Staph. aureus is a commensal human germ (50% of the population hosting S.aureus) but can be an opportunistic agent due to its pyogenic and toxinogenic behaviour. It represents a major public health problem.
- Easy to read: compared to Blood Agar, CHROMagar Staph aureus allows easy differentiation of mauve from blue or white colonies and is of considerable help in identifying suspect colonies.
- Higher sensitivity (exceeds 99%*) than Blood Agar, especially in specimens heavily loaded with gram negative flora competing with and inhibiting S.aureus. *Specificity and sensibility from scientific study: “Evaluation of CHROMagar Staph aureus, a new chromogenic medium, for isolation and presumptive identification of Staphylococcus aureus from human clinical specimens.” Gaillot O. et al. 2001. Journal of Clinical Microbiology, 38: 1587-1591.
- Better selectivity and sensitivity compared to the conventional media, Mannitol Salt Agar (called Chapman Agar in Europe), which is showing an excessive rate of false positives and of false negatives.
- Lower workload: Blood Agar, another conventional medium for detecting Staphylococcus aureus, requires tedious and costly examination with immunological tests of 5-10 colonies per suspected sample. With CHROMagar Staph aureus, testing a single colony with typical colour for further identification will generally be sufficient for high probability detection of Staphylococcus aureus.