title: Subtilase cytotoxin-encoding subAB2 variants in verotoxin-producing Escherichia coli strains isolated from goats and sheep.
abstract: Subtilase cytotoxin (SubAB) is a cytotoxin which might contribute to the virulence of verotoxin-producing Escherichia coli (VTEC) strains in humans. Three variants of SubAB encoding genes have been described (subAB1, subAB2-1, and subAB2-2) and it has been suggested that the strains positive for two variants of subAB may be more pathogenic for humans. In this study, 188 subAB2-positive VTEC strains isolated from goats and sheep were investigated for the presence of the subAB2-1 and subAB2-2 variants by PCR. Eighty-one of the 132 (61.4%) caprine strains and 36 of the 56 (64.3%) ovine strains possessed the subAB2-1 variant and all ovine and caprine strains, except one, were positive for the subAB2-2 variant. The results of this study show for first time that the subAB2-1 and subAB2-2 variants are found in caprine subAB2-positive VTEC strains and confirm that both subAB2 variants are detected in ovine subAB2-positive VTEC strains. Since no significant difference in the presence of both subAB2 variants was found among strains belonging to serotypes associated with severe illness in humans and strains not belonging to these serotypes, the occurrence of two subAB2 variants seems not to be associated with a higher risk of severe disease in humans.
authors.affiliation: Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense, 28040 Madrid, Spain. Electronic address: jaorden@vet.ucm.es.
authors.forename: José A
authors.initials: JA
authors.lastname: Orden
authors.affiliation: Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense, 28040 Madrid, Spain. Electronic address: gdbernal@vet.ucm.es.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Domínguez-Bernal
authors.affiliation: Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense, 28040 Madrid, Spain. Electronic address: rifuente@vet.ucm.es.
authors.forename: Ricardo
authors.initials: R
authors.lastname: de la Fuente
authors.affiliation: Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense, 28040 Madrid, Spain. Electronic address: fjcarrion@vet.ucm.es.
authors.forename: Javier
authors.initials: J
authors.lastname: Carrión
mesh_terms: D000818:Animals; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D014644:Genetic Variation; D015511:Goat Diseases / Q000382:microbiology*; D006041:Goats / Q000382:microbiology; D006801:Humans; D012756:Sheep / Q000382:microbiology; D012757:Sheep Diseases / Q000382:microbiology*; D054323:Shiga-Toxigenic Escherichia coli / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism*; D013381:Subtilisins / Q000235:genetics / Q000378:metabolism*; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics
chemical_list: D029968:Escherichia coli Proteins; D037521:Virulence Factors; D013381:Subtilisins; C527234:subtilase cytotoxin, E coli
keywords: Goats; Sheep; Subtilase cytotoxin; Verotoxin-producing Escherichia coli