TABLE 1.
Performance of chromogenic agar culture with and without broth enrichment compared to that of Xpert MRSA PCRa
| Methods compared | % Sensitivity (95% CI) | % Specificity (95% CI) | PPV | NPV |
|---|---|---|---|---|
| MS for 24 h vs CA for 48 h | 97.1 (91.9-99.0) | 99.2 (97.8-99.7) | 97.1 | 99.2 |
| MS for 24 h vs TSB enrichment with MS subculture | 90.3 (83.4-94.5) | 100 (99.0-100) | 100 | 97.2 |
| Broth enrichment with MS subculture vs Xpert MRSA PCRb | 84.3 (77.2-89.5) | 100 (98.9 -100) | 100 | 94.5 |
a
A contingency table depicts the performance of chromogenic agar, broth enrichment, and Xpert MRSA for a convenience sample of hospitalized patients (n = 498). PPV, positive predictive value; NPV, negative predictive value.
b
Nine PCR-positive/MRSA-negative samples grew only MSSA by TSB enrichment. Testing for the presence of SCCmec variants was not performed.