title: Evaluation of PCR-based screening for vancomycin-resistant enterococci compared with a chromogenic agar-based culture method.
abstract: Rapid detection of vancomycin-resistant enterococci (VRE) infection is very important for control and prevention of nosocomial spread of these bacteria. A multiplex PCR method for rapid screening of VRE has recently been developed. We performed a prospective study of VRE screening tests to compare the performance of PCR to that of a chromogenic agar-based culture method. From January to December 2009, a total of 8815 rectal swab specimens were tested simultaneously for VRE by VRE selective culture and by PCR. The specimens were inoculated onto ChromID VRE agar containing 8 µg vancomycin ml⁻¹ and examined after 24 and 48 h of incubation. Identification and antibiotic susceptibility tests were performed using the automated VITEK-2 system and a supplementary E-test and disk diffusion test. Detection of the vanA and vanB genes was performed with the Seeplex VRE detection kit. Specimens were inoculated in enterococcosel broth for 16-24 h before PCR for enrichment of VRE. VRE were isolated from 741 of the 8815 specimens by chromogenic agar-based culture (8.4 %). vanA and vanB genotypes were detected in 758 (8.6 %) and 3 (0.03 %) specimens, respectively, by multiplex PCR. Sensitivity, specificity, positive predictive value and negative predictive value of PCR for detection of VRE were 98.2 %, 99.6 %, 95.7 %, and 99.8 %. No VRE were isolated from vanB-positive specimens. The overall performance of PCR is comparable to that of a chromogenic agar-based culture method for screening of VRE, so PCR could be an alternative or supportive method for effective control of nosocomial VRE infection.
authors: Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors: Ja Young
authors: JY
authors: Seo
authors: Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors: Pyung-Whan
authors: PW
authors: Kim
authors: Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors: Jang-Ho
authors: JH
authors: Lee
authors: Division of Infectious Disease, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors: Jae-Hoon
authors: JH
authors: Song
authors: Division of Infectious Disease, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors: Kyong-Ran
authors: KR
authors: Peck
authors: Division of Infectious Disease, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors: Doo-Ryeon
authors: DR
authors: Chung
authors: Division of Infectious Disease, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors: Cheol-In
authors: CI
authors: Kang
authors: Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors: Chang-Seok
authors: CS
authors: Ki
authors: Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors: Nam Yong
authors: NY
authors: Lee
mesh_terms: D000362:Agar / Q000737:chemistry; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001431:Bacteriological Techniques; D002863:Chromogenic Compounds; D016983:Enterococcus / Q000187:drug effects* / Q000302:isolation & purification*; D016908:Gram-Positive Bacterial Infections / Q000175:diagnosis / Q000382:microbiology; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods*; D011446:Prospective Studies; D014640:Vancomycin / Q000494:pharmacology*; D020713:Vancomycin Resistance
chemical_list: D000900:Anti-Bacterial Agents; D002863:Chromogenic Compounds; D014640:Vancomycin; D000362:Agar