Multiplex PCR detection of Shiga toxin-producing Escherichia coli strains belonging to serogroups O157, O103, O91, O113, O145, O111, and O26 experimentally inoculated in beef carcass swabs, beef trim, and ground beef.
J Food Prot
; 74(2): 228-39, 2011 Feb.
Article
em En
| MEDLINE
| ID: mdl-21333142
ABSTRACT
Numerous foodborne outbreaks are attributed to Shiga toxin-producing Escherichia coli (STEC) and have been recognized for causing gastrointestinal disease in humans. Beef products have been considered the principal source of STEC. A multiplex PCR assay enabling simultaneous detection of STEC O103, O91, O113, O145, O111, O157, and O26 was developed and evaluated in artificially contaminated beef carcass swabs, beef trim, and ground beef after overnight enrichment. Individual serogroups were experimentally inoculated at low (1 to 10 CFU/ml) and high (11 to 100 CFU/ml) levels, and with a cocktail of strains belonging to two, four, and six serogroups. There was no significant difference in detecting single STEC strains under the different conditions. Only when strains were combined were there significant differences in detection of all cocktail isolates in some of the beef products. To address this issue, four serogroups were experimentally inoculated together at three different estimated levels (10, 10(2), and 10(3) CFU/ml) in all three beef products. Results yielded no significant difference in detecting STEC at the three inoculation levels (10, 10(2), and 10(3) CFU/ml) in trim and carcass swabs, but there was a significant difference in detecting STEC at the lowest levels (10 and 10(2) CFU/ml) in the 8020 nonirradiated ground beef, and in the detection of STEC in irradiated ground beef. The findings from this study could provide industry and government agencies with a tool to evaluate the prevalence and incidence of STEC in beef products and their processing environments.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Bovinos
/
Reação em Cadeia da Polimerase
/
Escherichia coli Shiga Toxigênica
/
Carne
Tipo de estudo:
Diagnostic_studies
/
Risk_factors_studies
Limite:
Animals
/
Humans
Idioma:
En
Revista:
J Food Prot
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Estados Unidos