title: Molecular subtyping of Vibrio cholerae O1 and O139 by pulsed-field gel electrophoresis in Hong Kong: correlation with epidemiological events from 1994 to 2002.
abstract: Two hundred twenty isolates of Vibrio cholerae O1 and O139 collected from 1994 to 2002 in Hong Kong were analyzed by pulsed-field gel electrophoresis (PFGE). Chromosomal DNAs from all V. cholerae isolates in agarose plugs were digested with the restriction enzyme NotI, resulting in 20 to 27 bands. Sixty distinctive PFGE patterns in the range of 10 to 300 kb were noted among 213 isolates typeable by PFGE. By comparing the common PFGE patterns obtained from four well-defined outbreaks of V. cholerae O1 and O139 with those obtained from other, epidemiologically unrelated isolates during the study period, indistinguishable and similar PFGE patterns were identified, indicating their close relatedness, in agreement with the results of epidemiological investigations. Heterogeneous PFGE patterns (with four to six banding differences), however, were identified among strains that were imported from other parts of Asia, including Indonesia, India, and Pakistan. Correlations with epidemiological information further support the usefulness of PFGE as an epidemiological tool in laboratory investigations of suspected outbreaks. Standardization of PFGE methodology will allow international comparison of fingerprint patterns and will form the basis of a laboratory network for tracking V. cholerae.
authors.affiliation: Public Health Laboratories, Public Health Laboratory Centre, Hong Kong Department of Health, Shek Kip Mei, Kowloon, Hong Kong. kmkam@dh.gov.hk
authors.forename: Kai Man
authors.initials: KM
authors.lastname: Kam
authors.forename: Cindy Kit Yee
authors.initials: CK
authors.lastname: Luey
authors.forename: Yee Man
authors.initials: YM
authors.lastname: Tsang
authors.forename: Choi Ping
authors.initials: CP
authors.lastname: Law
authors.forename: Man Yu
authors.initials: MY
authors.lastname: Chu
authors.forename: Tze Leung
authors.initials: TL
authors.lastname: Cheung
authors.forename: Agatha Wai Huen
authors.initials: AW
authors.lastname: Chiu
mesh_terms: D015373:Bacterial Typing Techniques; D002771:Cholera / Q000453:epidemiology* / Q000382:microbiology; D004269:DNA, Bacterial / Q000032:analysis; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D016521:Electrophoresis, Gel, Pulsed-Field; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D041241:Vibrio cholerae O1 / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D041242:Vibrio cholerae O139 / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial; D015252:Deoxyribonucleases, Type II Site-Specific; C038565:GCGGCCGC-specific type II deoxyribonucleases