TABLE 1.
Comparison of PCR assay to culture on selective media for detecting gastrointestinal VRE colonization by perianal and rectal swaba
| Swab | Study swab
|
Previous phenotypec | Concordance (%) between the study genotype and previous phenotype | ||
|---|---|---|---|---|---|
| PCR genotypeb | Culture phenotype | Concordance (%) between the genotype and phenotype | |||
| Perianal swabs (n = 58)d | |||||
| PCR and culture positive (n = 11) | vanA (n = 9) | VanA (n = 9) | 100 | VanA (n = 10) | 100 |
| vanB (n = 3) | VanB (n = 2) | 100 | VanB (n = 2) | ||
| PCR positive and culture negative (n = 6) | vanA (n = 6) | VanA (n = 6) | 100 | ||
| VanB (n = 1) | |||||
| PCR negative and culture positive (n = 1) | VanA (n = 1) | VanA (n = 1) | |||
| PCR and culture negative (n = 40) | VanA (n = 30) | ||||
| VanB (n = 16) | |||||
| Rectal swabs (n = 46)e | |||||
| PCR and culture positive (n = 8) | vanA (n = 6) | VanA (n = 6) | 100 | VanA (n = 7) | 100 |
| vanB (n = 3) | VanB (n = 2) | 100 | VanB (n = 2) | ||
| PCR positive and culture negative (n = 12) | vanA (n = 5) | VanA (n = 11) | 50 | ||
| vanB (n = 8) | VanB (n = 4) | ||||
| PCR and culture negative (n = 26) | VanA (n = 19) | ||||
| VanB (n = 12) | |||||
a
Study genotypes and phenotypes and the previous culture phenotype are included.
b
Both vanA and vanB genetic elements detected from the same patient were counted for each category.
c
Both VanA and VanB phenotypes recovered from the same patient were counted for each category. The phenotype from the previous isolate was not available for one participant.
d
P = 0.059 by the McNemar test for paired samples.
e
P < 0.001 by the McNemar test for paired samples.