title: Isolation of verocytotoxin-producing Escherichia coli from milk filters in south-western Ontario.
abstract: A total of 1012 milk filters collected from 498 dairy farms in south-western Ontario during three study periods (December 1985-March 1986) were tested for the presence of verocytotoxin-producing Escherichia coli (VTEC). VTEC were detected and isolated using a Vero cell assay. Supernatants from 20 of the milk filter cultures had verocytotoxic activity and 7 VTEC strains were isolated from these positive samples. The prevalence of VTEC in the samples in each of the three study periods were 0.44, 0.65 and 0.99% respectively. All seven VTEC strains isolated were sensitive to commonly used antimicrobial agents. The serotypes of these strains were O 26.H11, O43.H2, O 153.H25, O ?. H8, O? .H19, O ?. non-motile, and Orough.H19. Two of these serotypes (O 153.H25 and O 26.H11) have previously been associated with disease in humans.
authors.affiliation: Health of Animals Laboratory, Agriculture Canada, Guelph, Ontario.
authors.forename: R C
authors.initials: RC
authors.lastname: Clarke
authors.forename: S A
authors.initials: SA
authors.lastname: McEwen
authors.forename: V P
authors.initials: VP
authors.lastname: Gannon
authors.forename: H
authors.initials: H
authors.lastname: Lior
authors.forename: C L
authors.initials: CL
authors.lastname: Gyles
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000096:biosynthesis*; D015373:Bacterial Typing Techniques; D003612:Dairying / Q000295:instrumentation; D004926:Escherichia coli / Q000145:classification / Q000302:isolation & purification* / Q000378:metabolism; D005374:Filtration / Q000295:instrumentation; D008892:Milk / Q000382:microbiology*; D009864:Ontario; D012703:Serotyping; D022622:Shiga Toxin 1
chemical_list: D001427:Bacterial Toxins; D022622:Shiga Toxin 1