Table 1.
Performance of Verigene BC-GP assay, compared with standard procedures, in positive clinical blood cultures
| Organism | No. of organisms in BC-GP panel isolated |
No. (%) of isolates correctly identifieda |
No. (%) of isolates incorrectly identified |
No. (%) of isolates not detectedb |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| CHOPc | CMCD | Total | CHOP | CMCD | Total | CHOP | CMCD | Total | CHOP | CMCD | Total | |
| S. aureus | ||||||||||||
| Methicillin-susceptible | 61 | 24 | 85 | 61/61 (100) | 23/24d (96) | 84/85 (99) | 0 (0) | 1/24 (4) | 1/85 (1) | 0 (0) | 0 (0) | 0 (0) |
| Methicillin-resistant | 10 | 11 | 21 | 10/10 (100) | 11/11 (100) | 21/21 (100) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) |
| S. epidermidis | ||||||||||||
| Methicillin-susceptible | 4 | 1 | 5 | 4/4 (100) | 0/1 (0) | 4/5 (80) | 0 (0) | 0 (0) | 0 (0) | 1/1 (100) | 1/5 (20) | |
| Methicillin-resistant | 50 | 6 | 56 | 48/50e (96) | 6/6 (100) | 54/56 (96) | 1/50 (2) | 0 (0) | 1/56 (2) | 1/50 (2) | 0 (0) | 1/56 (2) |
| Other CoNS | 15 | 2 | 17 | 14/15f (93) | 2/2 (100) | 16/17 (94) | 0 (0) | 0 (0) | 1/15 (7) | 0 (0) | 1/17 (6) | |
| E. faecium | ||||||||||||
| Vancomycin-susceptible | 1 | 3 | 4 | 1/1 (100) | 3/3 (100) | 4/4 (100) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) |
| Vancomycin-resistant | 1 | 0 | 1 | 1/1 (100) | 1/1 (100) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | |||
| E. faecalis, vancomycin-susceptible | 7 | 8 | 15 | 7/7 (100) | 7/8g (88) | 14/15 (93) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 1/8 (12) | 1/15 (7) |
| S. pneumoniae | 3 | 6 | 9 | 3/3 (100) | 6/6 (100) | 9/9 (100) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) |
| S. anginosus group | 1 | 1 | 1/1 (100) | 1/1 (100) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | ||||
| Other viridans group streptococci | 5 | 10 | 15 | 2/5 (40) | 8/10 (80) | 10/15h (66) | 3/5 (60) | 2/10 (20) | 5/15 (33) | 0 (0) | 0 (0) | 0 (0) |
| S. pyogenes | 0 | 1 | 1 | 1/1 (100) | 1/1 (100) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | ||
| S. agalactiae | 0 | 3 | 3 | 1/3 (33) | 1/3 (66) | 1/3 (33) | 1/3 (33) | 1/3 (33) | 1/3 (33) | |||
| Listeria monocytogenes | 0 | 1 | 1 | 1/1 (100) | 1/1 (100) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | |||
| Other Gram-positive organismsi | 11 | 6 | 17 | 7/11 (63) | 5/6 (83) | 12/17 (69) | 0 (0) | 0 (0) | 0 (0) | 4/11 (36) | 1/6 (17) | 5/17 (29) |
| Total | 168 | 83 | 251 | 158/166 (94) | 75/83 (90) | 233/251 (93) | 4/168 (2) | 4/83 (5) | 8/251 (3) | 6/168 (4) | 4/83 (5) | 10/251 (4) |
“Corrected identified” by BC-GP was defined as concordance between standard procedure results and BC-GP results for genus, species, and mecA or vanA/vanB status for S. aureus, S. epidermidis, E. faecium, and E. faecalis, genus and species for S. pneumoniae, S. anginosus group, S. pyogenes, S. agalactiae, and S. lugdunensis, “Staphylococcus spp.” for other coagulase-negative Staphylococcus spp., “Streptococcus spp.” for other viridans group Streptococcus spp., and “Listeria spp.” for L. monocytogenes.
“Not detected” by BC-GP was defined as a BC-GP result that was negative or “no call” due to internal control failure or signal variation.
CHOP, The Children's Hospital of Philadelphia; CMCD, Children's Medical Center of Dallas.
Standard procedures yielded methicillin-susceptible S. aureus, S. saprophyticus, and S. hominis. BC-GP reported mecA-positive S. aureus.
Standard procedures yielded methicillin-resistant S. epidermidis. BC-GP reported “Staphylococcus” (coagulase-negative Staphylococcus) in one case and no call due to internal control failure in the other.
Standard procedures yielded identification of S. warneri. BC-GP reported no call due to signal variation.
Standard procedures yielded a mixed culture with E. faecalis and E. faecium (both vancomycin susceptible). BC-GP reported E. faecium but not E. faecalis.
Standard procedures yielded identification of S. mitis/oralis. BC-GP reported S. pneumoniae.
Other Gram-positive organisms included Bacillus (1 isolate), Corynebacterium spp. (2 isolates), Micrococcus spp. (9 isolates), Rothia spp. (3 isolates), E. gallinarum (1 isolate), and Abiotrophia sp. (1 isolate).