title: Detection, isolation, and molecular subtyping of Escherichia coli O157:H7 and Campylobacter jejuni associated with a large waterborne outbreak.
abstract: The largest reported outbreak of waterborne Escherichia coli O157:H7 in the United States occurred in upstate New York following a county fair in August 1999. Culture methods were used to isolate E. coli O157:H7 from specimens from 128 of 775 patients with suspected infections. Campylobacter jejuni was also isolated from stools of 44 persons who developed diarrheal illness after attending this fair. There was one case of a confirmed coinfection with E. coli O157:H7 and C. jejuni. Molecular detection of stx(1) and stx(2) Shiga toxin genes, immunomagnetic separation (IMS), and selective culture enrichment were utilized to detect and isolate E. coli O157:H7 from an unchlorinated well and its distribution points, a dry well, and a nearby septic tank. PCR for stx(1) and stx(2) was shown to provide a useful screen for toxin-producing E. coli O157:H7, and IMS subculture improved recovery. Pulsed-field gel electrophoresis (PFGE) was used to compare patient and environmental E. coli O157:H7 isolates. Among patient isolates, 117 of 128 (91.5%) were type 1 or 1a (three or fewer bands different). Among the water distribution system isolates, 13 of 19 (68%) were type 1 or 1a. Additionally, PFGE of C. jejuni isolates revealed that 29 of 35 (83%) had indistinguishable PFGE patterns. The PFGE results implicated the water distribution system as the main source of the E. coli O157:H7 outbreak. This investigation demonstrates the potential for outbreaks involving more than one pathogen and the importance of analyzing isolates from multiple patients and environmental samples to develop a better understanding of bacterial transmission during an outbreak.
authors.affiliation: Wadsworth Center, New York State Department of Health, Albany, New York 12201, USA.
authors.forename: Dianna J
authors.initials: DJ
authors.lastname: Bopp
authors.forename: Brian D
authors.initials: BD
authors.lastname: Sauders
authors.forename: Alfred L
authors.initials: AL
authors.lastname: Waring
authors.forename: Joel
authors.initials: J
authors.lastname: Ackelsberg
authors.forename: Nellie
authors.initials: N
authors.lastname: Dumas
authors.forename: Ellen
authors.initials: E
authors.lastname: Braun-Howland
authors.forename: David
authors.initials: D
authors.lastname: Dziewulski
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Wallace
authors.forename: Molly
authors.initials: M
authors.lastname: Kelly
authors.forename: Tanya
authors.initials: T
authors.lastname: Halse
authors.forename: Kimberlee Aruda
authors.initials: KA
authors.lastname: Musser
authors.forename: Perry F
authors.initials: PF
authors.lastname: Smith
authors.forename: Dale L
authors.initials: DL
authors.lastname: Morse
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Limberger
mesh_terms: D002169:Campylobacter Infections / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission; D016123:Campylobacter jejuni / Q000235:genetics / Q000302:isolation & purification*; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission; D019453:Escherichia coli O157 / Q000235:genetics / Q000302:isolation & purification*; D005618:Fresh Water / Q000382:microbiology*; D006801:Humans; D016133:Polymerase Chain Reaction; D022622:Shiga Toxin 1 / Q000032:analysis / Q000235:genetics; D022641:Shiga Toxin 2 / Q000032:analysis / Q000235:genetics; D014481:United States / Q000453:epidemiology
chemical_list: D022622:Shiga Toxin 1; D022641:Shiga Toxin 2