title: Detection of Vibrio cholerae O1 and O139 in environmental water samples by an immunofluorescent-aggregation assay.
abstract: Environmental waters are an important reservoir for Vibrio cholerae, and effective surveillance of the pathogen can help to warn of and prevent infection with this potentially fatal pathogen. An immunofluorescent-aggregation (IFAG) assay to detect V. cholerae O1 and O139 was established and evaluated with estuarine water samples. The practical application of this assay was compared with the conventional culture method and real-time PCR. The IFAG method had a sensitivity of 10(3) CFU/ml for detection of V. cholerae O1 and O139 strains in a suspension containing 10 different species of enterobacterial strains (total, 10(5) CFU/ml). Ten fluorescent bacterial aggregate colonies were randomly picked and tested positive in serum agglutination tests for the V. cholerae O1 and O139 strains, showing a high specificity. The enrichment broths of 146 samples of estuarine water were tested, and the percentage positive by the IFAG assay was 19.9% (29/146), which was significantly higher than that of the conventional culture method (10.3%, 15/146; P < 0.01) but lower than that of real-time PCR (29.5%, 43/146; P < 0.01). The coincidence rates of real-time PCR and IFAG detection were decreased with the reduction of the V. cholerae concentration. The IFAG method, with a high specificity and a relatively high sensitivity, may be used for detection and isolation of V. cholerae in environmental water samples.
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Changping, Beijing, China.
authors.forename: Duochun
authors.initials: D
authors.lastname: Wang
authors.forename: Xuebin
authors.initials: X
authors.lastname: Xu
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Deng
authors.forename: Changyi
authors.initials: C
authors.lastname: Chen
authors.forename: Baisheng
authors.initials: B
authors.lastname: Li
authors.forename: Hailing
authors.initials: H
authors.lastname: Tan
authors.forename: Haibo
authors.initials: H
authors.lastname: Wang
authors.forename: Song
authors.initials: S
authors.lastname: Tang
authors.forename: Haiyan
authors.initials: H
authors.lastname: Qiu
authors.forename: Jingdiao
authors.initials: J
authors.lastname: Chen
authors.forename: Bixia
authors.initials: B
authors.lastname: Ke
authors.forename: Changwen
authors.initials: C
authors.lastname: Ke
authors.forename: Biao
authors.initials: B
authors.lastname: Kan
mesh_terms: D001431:Bacteriological Techniques / Q000379:methods*; D007118:Immunoassay / Q000379:methods; D016133:Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity; D014734:Vibrio cholerae / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D014871:Water Microbiology