Prospective, Multicenter Evaluation of the BD GeneOhm VanR Assay for Direct, Rapid Detection of Vancomycin-Resistant Enterococcus Species in Perianal and Rectal Specimens

• Published in: American journal of clinical pathology Vol. 134; no. 2; pp. 219 - 226
• Main Authors: USACHEVA, Elena A, GINOCCHIO, Christine C, MORGAN, Margie, MAGLANOC, Geronimo, MEHTA, Maitry S, TREMBLAY, Sebastien, KARCHMER, Tobi B, PETERSON, Lance R
• Format: Journal Article
• Language: English
• Published: Chicago, IL American Society of Clinical Pathologists 01.08.2010
• Subjects: Anal Canal - microbiology; Bacterial Proteins - isolation & purification; Biological and medical sciences; Carbon-Oxygen Ligases - isolation & purification; DNA, Bacterial - analysis; Enterococcus; Enterococcus - isolation & purification; False Positive Reactions; Female; Humans; Investigative techniques, diagnostic techniques (general aspects); Male; Medical sciences; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Polymerase Chain Reaction - methods; Prevalence; Reagent Kits, Diagnostic; Rectum - microbiology; Sensitivity and Specificity; Vancomycin Resistance; Enterococcus; Evaluation; Multicenter study; VRE; Infection control; Assay; Infection; Direct method; Prospective; Streptococcaceae; Anatomic pathology; Rapid technique; Surveillance; Perianal; Rectum; Bacteria; Micrococcales; Species; Real time polymerase chain reaction; Real-time polymerase chain reaction; Vancomycin-resistant enterococci
• ISSN: 0002-9173; 1943-7722
• DOI: 10.1309/AJCPR1K0QFLBJSNH

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.