Characterization of Shiga-toxin producing Escherichia coli isolated from meat products sold in San Luis, Argentina

Shiga toxin-producing Escherichia coli (STEC) in meat products was studied by four procedures which combined enrichment, immunomagnetic separation (IMS), plating, and a stx screening polymerase chain reaction. A total of 167 samples (57 ground beef, 58 fresh sausages, and 52 precooked sausages) were collected from retail markets in San Luis, Argentina. The number of stx-positive samples represented 11.4% of the total (19/167) distributed as follows: seven for raw ground beef (12.3%), six for precooked sausages (11.5%), and six for fresh sausages (10.3%). The stx-positive sample rate increased when IMS was included in detection protocols. The stx2 gene (16/19) was more frequently detected than stx1 (4/19). The eae, rfbEO157, and fliCh7 genes were also investigated in stx-positive samples. Three non-O157 STEC strains were isolated from one precooked sausage and one fresh sausage (1.2%, 2/167). Their potential pathogenicity, antimicrobial susceptibility, and genetic diversity were determined. This study highlights meat products as possible vehicles for transmission of STEC in this Argentine region. Practical applications: Meat products intended for human consumption can be vehicles for the transmission of Shiga toxin-producing Escherichia coli (STEC) in this region. STEC strains isolated from sausages in this work represent a hazard for consumers. Further research to continue the STEC surveillance in meat products from this region in Argentina and to improve the STEC detection procedures in these foods and other possible transmission vehicles of this pathogen is required. Additionally, livestock control programs as well as good practices for slaughtering, processing, and manufacturing plants should be implemented to reduce STEC spreading in the food chain. Adequate cooking of ground beef and fresh and precooked sausages is recommended to consumers.Fil: Salinas Ibañez, Angel Gabriel. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; ArgentinaFil: Lucero Estrada, Cecilia Stella Marys. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Favier, Gabriela Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; ArgentinaFil: Vega, Alba Edith. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; ArgentinaFil: Stagnitta, Patricia Virginia. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; ArgentinaFil: Mattar Domínguez, María Aída. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; ArgentinaFil: Zolezzi, Gisela. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”; ArgentinaFil: Carbonari, Claudia Carolina. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”; ArgentinaFil: Miliwebsky, Elizabeth. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”; ArgentinaFil: Cortiñas, Teresa Inés. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; ArgentinaFil: Escudero, María Esther. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; Argentin