title: First isolation of the enterohaemorrhagic Escherichia coli O145:H- from cattle in feedlot in Argentina.
abstract: BACKGROUND
  Enterohaemorrhagic Escherichia coli (EHEC) is considered to be common cause of haemorrhagic colitis (HC), thrombotic thrombocytopenic purpura and haemolytic uraemic syndrome (HUS) in humans. In a previous paper, we have demonstrated that EHEC are commonly found in the intestines of livestock. Infections in humans are, in part, a consequence of consumption of undercooked meat or raw milk. Argentina has one of the highest records of HUS (300-400 cases/year; 22/100,000 children under 4 years of age). The aim of this work is to communicate the first isolation of O145:H-from cattle in this country and characterize the virulence cassette, providing useful information to evaluate the risk of foodborne transmission of this emergent non-O157:H7 serotype.
  
  
  RESULTS
  EHEC O145:H- was isolated from cattle in an Argentinian feedlot. Pheno- and genotype of nine strains were characterized, corresponding to several virulence cassettes: VT2+eaeA+ Mp+ (n = 5), VT2+eaeA+ (n = 1), VT1+eaeA+ Mp+ (n = 2), and VT1+eaeA+ (n = 1). Strains isolated from the same animal were considered only when they showed a different virulence pattern. The clonal relationship was studied by RAPD. Strains were distributed in two RAPD profiles, which corresponded to the presence of either, VT1+ or VT2+ genotype. No difference was detected by RAPD analysis between Mp+ or Mp- strains.
  
  
  CONCLUSIONS
  This was the first isolation of EHEC O145:H- serotype in Argentina enlarging the list of non-O157:H7 serotypes isolated from cattle in this country by us. All O145:H-strains carried several virulence factors which allow us to predict their potential ability to develop haemolytic uraemic syndrome in humans.
authors.affiliation: Laboratorio de Inmunoquímica y Biotecnología, Animal Health Department, Universidad Nacional del Centro-CIC, 7000 Tandil, Argentina. nlpadola@vet.unicen.edu.ar
authors.forename: Nora L
authors.initials: NL
authors.lastname: Padola
authors.forename: Marcelo E
authors.initials: ME
authors.lastname: Sanz
authors.forename: Paula M A
authors.initials: PM
authors.lastname: Lucchesi
authors.forename: Jesús E
authors.initials: JE
authors.lastname: Blanco
authors.forename: Jorge
authors.initials: J
authors.lastname: Blanco
authors.forename: Miguel
authors.initials: M
authors.lastname: Blanco
authors.forename: Analía I
authors.initials: AI
authors.lastname: Etcheverría
authors.forename: Guillermo H
authors.initials: GH
authors.lastname: Arroyo
authors.forename: Alberto E
authors.initials: AE
authors.lastname: Parma
mesh_terms: D000821:Animal Feed / Q000382:microbiology*; D000818:Animals; D001118:Argentina; D002417:Cattle; D019453:Escherichia coli O157 / Q000276:immunology / Q000302:isolation & purification* / Q000378:metabolism / Q000472:pathogenicity; D006470:Hemorrhage / Q000382:microbiology*; D019105:Random Amplified Polymorphic DNA Technique; D012703:Serotyping; D022603:Shiga Toxins / Q000378:metabolism; D014774:Virulence
chemical_list: D022603:Shiga Toxins