TABLE 1.
Results obtained by standard growth-based and molecular assays with a collection of 93 MRSA and 89 MSSA isolatesa
| Assay or protocol | Sensitivity | Specificity | Positive predictive value | Negative predictive value |
|---|---|---|---|---|
| Culture | 1 | 1 | 1 | 1 |
| qMRSA | 1 | 1 | 1 | 1 |
| BD | 0.94 | 0.64 | 0.71 | 0.92 |
| Hain 1 | 0.90 | 0.53 | 0.66 | 0.84 |
| Hain 2 | 0.67 | 0.57 | 0.61 | 0.63 |
a
Three MRSA strains from our collection were found to be negative by qMRSA after they were thawed. These isolates were tested by standard growth-based methods and identified as MSSA. The excision of the mecA gene obviously yields negative results when this gene is targeted. These isolates generated false-positive results when they were tested by the two other molecular assays. The data for these three isolates were therefore not included in the analysis presented here.