title: Perirectal swab surveillance for Clostridium difficile by use of selective broth preamplification and real-time PCR detection of tcdB.
abstract: Active surveillance testing to identify and isolate asymptomatic carriers of toxigenic Clostridium difficile has been limited by the lack of a test that is sensitive, specific, and timely enough to serve as an infection control tool. We tested DNA preamplified from perirectal surveillance specimens in a liquid medium selective for C. difficile by using a modified commercial real-time PCR assay. All fermenting specimens were subcultured, and isolates were tested for toxigenicity. Culture-positive toxigenic isolates served as the gold standard for comparison with the broth preamplification/PCR assay. The limit of detection for the assay was 1 CFU. Relative to toxigenic anaerobic culture, the sensitivity, specificity, and positive and negative predictive values of this assay were 70/70 (100.0%), 422/426 (99.1%), 70/74 (94.6%), and 422/422 (100.0%), respectively. These data demonstrate that selective broth preamplification and real-time PCR of perirectal swab specimens constitute a practical approach to the detection of asymptomatic C. difficile carriage.
authors: Division of Infectious Diseases, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA. currysr@upmc.edu
authors: Scott R
authors: SR
authors: Curry
authors: Jessica L
authors: JL
authors: Schlackman
authors: Travis M
authors: TM
authors: Hamilton
authors: Tatianna K
authors: TK
authors: Henderson
authors: Nakita T
authors: NT
authors: Brown
authors: Jane W
authors: JW
authors: Marsh
authors: Kathleen A
authors: KA
authors: Shutt
authors: Maria M
authors: MM
authors: Brooks
authors: A William
authors: AW
authors: Pasculle
authors: Carlene A
authors: CA
authors: Muto
authors: Lee H
authors: LH
authors: Harrison
mesh_terms: D001003:Anal Canal / Q000382:microbiology*; D001426:Bacterial Proteins / Q000235:genetics*; D001427:Bacterial Toxins / Q000235:genetics*; D001431:Bacteriological Techniques / Q000379:methods; D002353:Carrier State / Q000175:diagnosis* / Q000382:microbiology; D016360:Clostridioides difficile / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D003015:Clostridium Infections / Q000175:diagnosis* / Q000382:microbiology; D006801:Humans; D010502:Perineum / Q000382:microbiology*; D011237:Predictive Value of Tests; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D018571:Sentinel Surveillance
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; C031815:toxB protein, Clostridium difficile