Prospective, multicenter evaluation of the BD GeneOhm VanR assay for direct, rapid detection of vancomycin-resistant Enterococcus species in perianal and rectal specimens.
The BD GeneOhm VanR assay (BD Diagnostics, San Diego, CA), a qualitative test for the rapid detection of vancomycin-resistant enterococci (VRE) from rectal and/or perianal swabs, combines integrated nucleic acid extraction and automated polymerase chain reaction for the detection of vanA and/or vanB gene sequences. We studied 1,027 perianal and rectal swab specimens from 3 geographically distinct US sites (prevalence rates, 13.1%-25.8%). Direct swab specimens were tested by the assay and compared with direct culture. The sensitivity, specificity, and positive and negative predictive values of the assay were 93.2%, 81.9%, 54.4%, and 98.1%, respectively. The specificity was limited largely due to false-positives in the vanB portion of the assay. Specificity with perianal swabs was significantly greater than with rectal swabs, 87.1% vs 74.7%, respectively (P < .0001). When used only to detect resistance conferred by vanA, the assay was 88.3% (158/179) sensitive and 95.8% (802/837) specific, with positive and negative predictive values of 81.9% and 97.4%, respectively. The assay is a simple, rapid, and acceptable method for screening for VRE in a variety of populations in which vanA is the predominant genotype. Samples positive for the vanB genotype should be confirmed by culture owing to the apparent high number of false-positive results.
Usacheva
Elena A
EA
Microbiology and Infectious Diseases Research, NorthShore University HealthSystem, Evanston, IL 60201-1781, USA.
Ginocchio
Christine C
CC
Morgan
Margie
M
Maglanoc
Geronimo
G
Mehta
Maitry S
MS
Tremblay
Sebastien
S
Karchmer
Tobi B
TB
Peterson
Lance R
LR
D001003:Anal Canal / Q000382:microbiology*; D001426:Bacterial Proteins / Q000302:isolation & purification; D019729:Carbon-Oxygen Ligases / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000032:analysis; D016983:Enterococcus / Q000302:isolation & purification*; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008297:Male; D016133:Polymerase Chain Reaction / Q000379:methods*; D015995:Prevalence; D011933:Reagent Kits, Diagnostic; D012007:Rectum / Q000382:microbiology*; D012680:Sensitivity and Specificity; D020713:Vancomycin Resistance
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D011933:Reagent Kits, Diagnostic; C071437:VanA ligase, Bacteria; C079913:VanB protein, Enterococcus; D019729:Carbon-Oxygen Ligases