Molecular screening of bovine raw milk for the presence of Shiga toxin-producing Escherichia coli (STEC) on dairy farms

Milkborne transmission of Shiga toxin- producing Escherichia coli (STEC) has raised considerable concern due to recent outbreaks worldwide and poses a threat to public health. The aim of this study was to develop a sensitive and specific multiplex PCR assay to detect the presence of STEC in bovine r...

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Detalles Bibliográficos
Autores: Vendramin,Tatiane, Kich,Débora Mara, Molina,Rachel Dias, Souza,Claucia Fernanda Volken de, Salvatori,Rosangela Uhrig, Pozzobon,Adriane, Bustamante-filho,Ivan Cunha
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2014
País:Brasil
Institución:Sociedade Brasileira de Ciência e Tecnologia de Alimentos (SBCTA)
Repositorio:Food Science and Technology (Campinas)
Idioma:inglés
OAI Identifier:oai:scielo:S0101-20612014000300025
Acceso en línea:http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612014000300025
Access Level:acceso abierto
Palabra clave:shiga-toxin
cattle
multiplex PCR
milk
Descripción
Sumario:Milkborne transmission of Shiga toxin- producing Escherichia coli (STEC) has raised considerable concern due to recent outbreaks worldwide and poses a threat to public health. The aim of this study was to develop a sensitive and specific multiplex PCR assay to detect the presence of STEC in bovine raw milk. To identify E. coli (ATCC 25922) contamination, the gene uspA was used, and PCR sensitivity and specificity were accessed by testing diluted samples ranging from 2 to 2.0 × 10(6) CFU/mL. To detect STEC, the stx1 and stx2 genes were selected as targets. After reaction standardization, the multiplex assay was tested in raw milk collected from 101 cows on dairy farms. PCR assay for E. coli detection had a specificity of 100% and sensitivity of 79% (P<0.0001), with a lower detection limit of 2 CFU/mL. Multiplex PCR assay had 100% sensitivity for E. coli positive raw milk samples, and 31.1% were contaminated with STEC, 28.3% of stx2, and 1.9% of stx1. The multiplex PCR assay described in the present study can be employed to identify and screen E. coli harboring stx1 and stx2 genes in raw milk on dairy farms and in industries.