title: Relatedness of Vibrio cholerae O1/O139 isolates from patients and their household contacts, determined by multilocus variable-number tandem-repeat analysis.
abstract: The genetic relatedness of Vibrio cholerae O1/O139 isolates obtained from 100 patients and 146 of their household contacts in Dhaka, Bangladesh, between 2002 and 2005 was assessed by multilocus variable-number tandem-repeat analysis. Isolate genotypes were analyzed at five loci containing tandem repeats. Across the population, as well as within households, isolates with identical genotypes were clustered in time. Isolates from individuals within the same household were more likely to have similar or identical genotypes than were isolates from different households, but even within a household, isolates from different individuals often had different genotypes. When household contacts were sampled regularly for 3 weeks after the illness of the household index patient, isolates with genotypes related to the index patient appeared in contacts, on average, approximately 3 days after the index patient, while isolates with unrelated genotypes appeared in contacts approximately 6 days after. Limited data revealed that multiple isolates from the same individual collected within days of each other or even from a single stool sample may have identical, similar, or unrelated genotypes as well. Our results demonstrate that genetically related V. cholerae strains cluster in local outbreaks but also suggest that multiple distinct strains of V. cholerae O1 may circulate simultaneously within a household.
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh.
authors.forename: Emily A
authors.initials: EA
authors.lastname: Kendall
authors.forename: Fahima
authors.initials: F
authors.lastname: Chowdhury
authors.forename: Yasmin
authors.initials: Y
authors.lastname: Begum
authors.forename: Ashraful I
authors.initials: AI
authors.lastname: Khan
authors.forename: Shan
authors.initials: S
authors.lastname: Li
authors.forename: James H
authors.initials: JH
authors.lastname: Thierer
authors.forename: Jason
authors.initials: J
authors.lastname: Bailey
authors.forename: Kristen
authors.initials: K
authors.lastname: Kreisel
authors.forename: Carol O
authors.initials: CO
authors.lastname: Tacket
authors.forename: Regina C
authors.initials: RC
authors.lastname: LaRocque
authors.forename: Jason B
authors.initials: JB
authors.lastname: Harris
authors.forename: Edward T
authors.initials: ET
authors.lastname: Ryan
authors.forename: Firdausi
authors.initials: F
authors.lastname: Qadri
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Calderwood
authors.forename: O Colin
authors.initials: OC
authors.lastname: Stine
mesh_terms: D015373:Bacterial Typing Techniques; D001459:Bangladesh / Q000453:epidemiology; D002771:Cholera / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology; D016358:Contact Tracing; D004269:DNA, Bacterial / Q000032:analysis; D004196:Disease Outbreaks; D005191:Family Characteristics; D005838:Genotype; D006801:Humans; D018598:Minisatellite Repeats / Q000235:genetics*; 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