title: Performance of chromID Clostridium difficile agar compared with BBL C. difficile selective agar for detection of C. difficile in stool specimens.
abstract: We evaluated the performance of a new chromogenic medium for detection of Clostridium difficile, chromID C. difficile agar (CDIF; bioMérieux, France), by comparison with BBL C. difficile Selective Agar (CDSA; Becton Dickinson and Company, USA). After heat pre-treatment (80℃, 5 min), 185 diarrheal stool samples were inoculated onto the two media types and incubated anaerobically for 24 hr and 48 hr for CDIF and for 48 hr and 72 hr for CDSA. All typical colonies on each medium were examined by Gram staining, and the gram-positive rods confirmed to contain the tpi gene by PCR were identified as C. difficile. C. difficile was recovered from 36 samples by using a combination of the two media. The sensitivity with CDIF 48 hr was highest (100%) and was significantly higher than that with CDIF 24 hr (58.3%; P<0.001), because samples with a low burden of C. difficile tended to require prolonged incubation up to 48 hr (P<0.001). The specificity of CDIF 24 hr and CDIF 48 hr (99.3% and 90.6%, respectively) was significantly higher than that of CDSA 48 hr and CDSA 72 hr (72.5% and 67.1%, respectively; P<0.001). CDIF was effective for detecting C. difficile in heat-pretreated stool specimens, thus reducing unnecessary testing for toxin production in non-C. difficile isolates and turnaround time.
authors.affiliation: Department of Laboratory Medicine, Yeouido St. Mary's Hospital, Seoul, Korea.
authors.forename: Sang Bong
authors.initials: SB
authors.lastname: Han
authors.affiliation: Department of Laboratory Medicine, Seoul St. Mary's Hospital, Seoul, Korea.
authors.forename: Jiyoung
authors.initials: J
authors.lastname: Chang
authors.affiliation: Department of Laboratory Medicine, Seoul St. Mary's Hospital, Seoul, Korea.
authors.forename: Sang Hyun
authors.initials: SH
authors.lastname: Shin
authors.affiliation: Department of Laboratory Medicine, Seoul St. Mary's Hospital, Seoul, Korea.
authors.forename: Kang Gyun
authors.initials: KG
authors.lastname: Park
authors.affiliation: Department of Laboratory Medicine, Seoul St. Mary's Hospital, Seoul, Korea.
authors.forename: Gun Dong
authors.initials: GD
authors.lastname: Lee
authors.affiliation: Department of Biostatistics, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Yong Gyu
authors.initials: YG
authors.lastname: Park
authors.affiliation: Department of Laboratory Medicine, Seoul St. Mary's Hospital, Seoul, Korea.
authors.forename: Yeon-Joon
authors.initials: YJ
authors.lastname: Park
mesh_terms: D000362:Agar / Q000737:chemistry; D001426:Bacterial Proteins / Q000235:genetics; D001431:Bacteriological Techniques / Q000379:methods*; D002863:Chromogenic Compounds / Q000737:chemistry / Q000378:metabolism; D016360:Clostridioides difficile / Q000235:genetics / Q000302:isolation & purification*; D003470:Culture Media / Q000737:chemistry; D004269:DNA, Bacterial / Q000032:analysis / Q000378:metabolism; D003967:Diarrhea / Q000382:microbiology / Q000473:pathology; D005243:Feces / Q000382:microbiology*; D006801:Humans; D016133:Polymerase Chain Reaction; D013997:Time Factors
chemical_list: D001426:Bacterial Proteins; D002863:Chromogenic Compounds; D003470:Culture Media; D004269:DNA, Bacterial; D000362:Agar
keywords: ChromID C. difficile agar; Chromogenic agar; Clostridium difficile; Performance; Toxigenic culture