Virulence genes and intimin types of Shiga-toxin-producing Escherichia coli isolated from cattle and beef products in Argentina
- Miguel Blanco 1
- Nora L. Padola 2
- Alejandra Krüger 2
- Marcelo E. Sanz 2
- Jesús E. Blanco 1
- Enrique A. González 1
- Ghizlane Dahbi 1
- Azucena Mora Gutierrez 1
- Isabel Bernárdez Hermida 1
- Analía I. Etcheverría 2
- Guillermo H. Arroyo 2
- Paula M.A. Lucchesi 2
- Alberto E. Parma 2
- Jorge Blanco Álvarez 1
- 1 E. coli Reference Laboratory (LREC), Department of Microbiology and Parasitology, Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain
- 2 Laboratory of Immunochemistry and Biotechnology, Faculty of Veterinary Sciences, University Nacional del Centro PBA, Tandil, Argentina
ISSN: 1618-1905
Ano de publicación: 2004
Volume: 7
Número: 4
Páxinas: 269-276
Tipo: Artigo
Outras publicacións en: International microbiology: official journal of the Spanish Society for Microbiology
Resumo
A total of 153 Shiga-toxin-producing Escherichia coli (STEC) isolates from feces of cattle and beef products (hamburgers and ground beef) in Argentina were characterized in this study. PCR showed that 22 (14%) isolates carried stx1 genes, 113 (74%) possessed stx2 genes and 18 (12%) both stx1 and stx2. Intimin (eae), enterohemolysin (ehxA), and STEC autoagglutinating adhesin (saa) virulence genes were detected in 36 (24%), 70 (46%) and in 34 (22%) of the isolates, respectively. None of 34 saa-positive isolates carried the gene eae, and 31 were ehxA-positive. Fourteen (7 of serotype O26:H11 and 4 of serotype O5:H-) isolates had intimin β1, 16 isolates possessed intimin γ1 (11 of serotype O145:Hand 5 of serotype O157:H7), 5 isolates had intimin type ε1 (4 of serotypes O103:Hand O103:H2), and one isolate O111:H- showed intimin type θ/γ2. Although the 153 STEC isolates belonged to 63 different seropathotypes, only 12 accounted for 58% of isolates. Seropathotype ONT:H- stx2 (18 isolates) was the most common, followed by O171:H2 stx2 (12 isolates), etc. The majority (84%) of STEC isolates belonged to serotypes previously found in human STEC and 56% to serotypes associated with STEC isolated from patients with hemolytic uremic syndrome (HUS). Thus, this study confirms that cattle are a major reservoir of STEC pathogenic for humans. To our knowledge, this is the first study that described the presence of saa gene in STEC of serotypes O20:H19, O39:H49, O74:H28, O79:H19, O116:H21, O120:H19, O141:H7, O141:H8, O174:H21, and ONT:H21. The serotypes O120:H19 and O185:H7 were not previously reported in bovine STEC. [Int Microbiol 2004; 7(4):269-276]