TABLE 1.
Summary of method comparison results for detection of carbapenem-resistant organisms from rectal swabs
| Parameter | No. (%) bya: |
|||||
|---|---|---|---|---|---|---|
| CDC | CDC + Vanco | Direct MAC | chromID CARBA | Check-Direct CPE screen | Total | |
| Broth enrichment | ||||||
| Cultures with turbid broths | 157 (73.7) | 72 (33.8) | NA | NA | NA | NA |
| Cultures with growth on subculture from turbid broth to MacConkey plate with ertapenem disk | 71 (33.3) | 35 (16.4) | NA | NA | NA | NA |
| Direct selective culture | ||||||
| Cultures with any growth on plates after inoculation with specimen | NA | NA | 146 (68.5) | 29 (13.6) | NA | NA |
| Recovered organisms by culture-based methods | ||||||
| Cultures positive with GNB recovered that required further workupb | 27 (12.7) | 21 (9.9) | 36 (16.9) | 26 (12.2) | NA | 41 (19.2) |
| Cultures positive with CROs | 11 (5.2) | 8 (3.8) | 18 (8.5) | 15 (7.0) | NA | 20 (9.4) |
| Cultures positive with CPOs | 2 (0.9) | 1 (0.5) | 4 (1.9) | 5 (2.3) | NA | 5 (2.3) |
| Check-Direct CPE screen molecular results | ||||||
| Swabs carbapenemase gene positive | NA | NA | NA | NA | 10 (4.7) | 10 (4.7) |
a
See Table S1 in the supplemental material for expanded Table 1 results summarizing the organisms recovered. CDC, CDC broth enrichment method; CDC + vanco, CDC broth enrichment method with the addition of a vancomycin disk; Direct MAC, direct MacConkey plate with ertapenem disks; NA, not applicable.
b
Criteria for further workup included recovery of Gram-negative bacilli (GNB) that grew within 27 mm of the ertapenem disk for the CDC, CDC + Vanco, and Direct MAC methods or growth on chromID CARBA medium.