title: Frequency of Shiga toxin-producing Escherichia coli (STEC) isolates among diarrheic and non-diarrheic calves in Brazil.
abstract: The occurrence of Shiga toxin (Stx) gene sequences was examined in 344 fecal samples from diarrheic (n=139) and non-diarrheic (n=205) calves from 12 beef farms in São Paulo State, Brazil to study the prevalence of Shiga toxin-producing Escherichia coli (STEC) strains. Forty-four (12.7%) animals were found to be positive for stx. The frequency of carriage of stx was higher in diarrheic calves (28/139, 20%) than in non-diarrheic animals (16/205, 7.8%) (P<0.001). Among the 24 STEC strains recovered from the animals, 12 isolates carried stx1, four stx2, and 8 carried both stx1 and stx2 genes. The eae and the enterohaemolysin (Ehly) gene sequences occurred at high frequencies in these STEC strains (41.6 and 50.0%, respectively). A total of 16 serotypes were identified. The serotypes O111:NM (four isolates), O111:H8 (two) and O118:H16 (one), currently described as enterohaemorrhagic E. coli (EHEC), were isolated from cattle in Brazil for the first time. These findings reinforce the importance of cattle as a reservoir of EHEC strains in Brazil.
authors.affiliation: Departamento de Microbiologia, Instituto de Ciências Biomédicas II, Universidade de São Paulo, 05508-900 Sao Paulo, SP, Brazil.
authors.forename: L
authors.initials: L
authors.lastname: Leomil
authors.forename: L
authors.initials: L
authors.lastname: Aidar-Ugrinovich
authors.forename: B E C
authors.initials: BE
authors.lastname: Guth
authors.forename: K
authors.initials: K
authors.lastname: Irino
authors.forename: M P
authors.initials: MP
authors.lastname: Vettorato
authors.forename: D L
authors.initials: DL
authors.lastname: Onuma
authors.forename: A F P
authors.initials: AF
authors.lastname: de Castro
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000378:metabolism; D001427:Bacterial Toxins / Q000235:genetics / Q000378:metabolism; D001938:Brazil / Q000453:epidemiology; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000382:microbiology*; D002522:Chlorocebus aethiops; D003601:Cytotoxicity Tests, Immunologic; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D003967:Diarrhea / Q000382:microbiology / Q000662:veterinary; D004926:Escherichia coli / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D029968:Escherichia coli Proteins; D005243:Feces / Q000382:microbiology; D019081:O Antigens / Q000378:metabolism; D016133:Polymerase Chain Reaction; D015995:Prevalence; D022603:Shiga Toxins / Q000096:biosynthesis* / Q000235:genetics; D014709:Vero Cells
chemical_list: D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D004269:DNA, Bacterial; C097321:EHEC-hlyA protein, E coli; D029968:Escherichia coli Proteins; C022863:H antigen; D019081:O Antigens; D022603:Shiga Toxins