Shiga toxin-producing Escherichia coli in healthy young beef steers from Argentina: prevalence and virulence properties

• Autores: Meichtri, Lelis; Miliwebsky, Elizabeth; Gioffré, Andrea; Chinen, Isabel; Baschkier, Ariela; Chillemi, Germán; Guth, Beatriz E C; Masana, Marcelo; Cataldi, A.; Rodríguez, H; Rivas, Marta
• Año de publicación: 2004
• Idioma: inglés
• Tipo de recurso: artículo
• Fuente: International Journal of Food Microbiology 2004; 96(2):189-98.
• Materia: Toxina Shiga; Escherichia coli; Argentina
• Institución: Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos G. Malbrán"

Fil: Meichtri, Lelis. Instituto Tecnologı́a de Alimentos, Centro de Investigación de Agroindustria, Instituto Nacional de Tecnologı́a Agropecuaria, Argentina, C.C. 77. C.P. (B1708WAB), Morón, Buenos Aires; Argentina.
Fil: Miliwebsky, Elizabeth. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio Fisiopatogenia; Argentina.
Fil: Gioffré, Andrea. Instituto de Biotecnologı́a, Centro de Investigación de Ciencias Veterinarias y Agronómicas, Instituto Nacional de Tecnologı́a Agropecuaria, Argentina. Los Reseros y Las Cabañas, (1712) Castelar, Buenos Aires; Argentina.
Fil: Chinen, Isabel. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio Fisiopatogenia; Argentina.
Fil: Baschkier, Ariela. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio Fisiopatogenia; Argentina.
Fil: Chillemi, Germán. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio Fisiopatogenia; Argentina.
Fil: Guth, Beatriz E C. Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo. Rua Botucatu, 862-3 andar, Vila Clementino, São Paulo; Brasil.
Fil: Masana, Marcelo. Instituto Tecnologı́a de Alimentos, Centro de Investigación de Agroindustria, Instituto Nacional de Tecnologı́a Agropecuaria, Argentina, C.C. 77. C.P. (B1708WAB), Morón, Buenos Aires; Argentina.
Fil: Cataldi, A. Instituto de Biotecnologı́a, Centro de Investigación de Ciencias Veterinarias y Agronómicas, Instituto Nacional de Tecnologı́a Agropecuaria, Argentina. Los Reseros y Las Cabañas, (1712) Castelar, Buenos Aires; Argentina.
Fil: Rodríguez, H. Instituto Tecnologı́a de Alimentos, Centro de Investigación de Agroindustria, Instituto Nacional de Tecnologı́a Agropecuaria, Argentina, C.C. 77. C.P. (B1708WAB), Morón, Buenos Aires; Argentina.
Fil: Rivas, Marta. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio Fisiopatogenia; Argentina.
Between July 1999 and December 2000, the prevalence of Shiga toxin-producing Escherichia coli (STEC) was established in 200 Argentine healthy young beef steers (14-16 months old) grown under local production systems with a feed grain period of 3-4 months, and the STEC strains isolated were examined in regard to their phenotypic and genotypic characteristics. Stool samples (n = 70) and rectal swabs (n = 130) were taken at the slaughterhouse level. By polymerase chain reaction (PCR), Shiga toxin (stx) gene sequences were detected in 69% of the samples. Eighty-six STEC strains were isolated from 39% of the animals. Serogroups identified, in order of frequency, were: O8 (16 strains), O113 (14), O103 (5), O91 (4), O171 (3), O174 (3), O25 (2), O112 (2), O145 (2), O2, O11, O104, O121, O128, O143, O146, O157. The most frequent serotype isolated was O8:H19 (12.9%). A total of 17 serotypes, including E. coli O157:H7 found in one animal (0.5%), have been previously associated with hemolytic uremic syndrome (HUS), bloody and non-bloody diarrhea in different countries, including Argentina. The prevalent genotype isolated was stx2 (51 of 86, 59.3%). Subtyping of stx2 variants showed the prevalence of stx2vh-b (25.6%) and stx2vh-a types (24.4%), and revealed the presence of an atypical stx2-v. Only 7.0% of STEC strains carried eae, and 33.7% harbored EHEC-hlyA gene. The full virulent genotype (stx/eae/EHEC-hlyA) was found to be present in 4 of the 86 (4.7%) STEC strains isolated. This research indicates that young steers from the main beef-producing area of Argentina are an important reservoir of STEC strains; however, its importance as agents of human diseases in our country has still to be established.