Fluorescent protein-marked Escherichia coli biotype I strains as surrogates for enteric pathogens in validation of beef carcass interventions.
J Food Prot
; 72(2): 295-303, 2009 Feb.
Article
en En
| MEDLINE
| ID: mdl-19350974
ABSTRACT
The efficacy of antimicrobial interventions implemented in slaughter establishments to reduce enteric pathogens on beef carcasses should optimally be validated under commercial operation conditions. This study was conducted to identify surrogate organisms for enteric pathogens that could be used to validate beef carcass interventions. The growth, resistance, and attachment properties of nonpathogenic fluorescent protein-marked Escherichia coli strains were compared with those of E. coli O157H7 and Salmonella strains. Growth curves were obtained based on growth in tryptic soy broth at 37 degrees C. In general, growth parameters were not different among potential surrogates and target pathogens (P > 0.05). Thermal resistance was compared in phosphate-buffered saline (pH 7.4) at 55, 60, and 65 degrees C, and D-values of potential surrogates were not different (P > 0.05) or were higher (P < 0.05) than those of the target pathogens. Acid resistance was tested in phosphate-buffered saline acidified with L-lactic acid at pH 2.5, 3.0, and 3.5, and log reductions (CFU per milliliter) were not different (P > 0.05) among potential surrogates and E. coli O157H7 strains; however, some Salmonella serotypes were less acid resistant than were surrogates (P < 0.05). The cell surface hydrophobicity was different (P < 0.05) among surrogates and some E. coli O157H7 strains, but the strength of attachment to beef carcasses was not different (P > 0.05) among all microorganisms. Log reductions (CFU per square centimeter) after application of hot water washes and 2% L-lactic acid sprays on beef carcasses were not different (P > 0.05) among surrogates and pathogens. The nonpathogenic E. coli strains evaluated in this study could be used as surrogates for E. coli O157H7 and Salmonella to validate hot water and lactic acid interventions on beef carcasses.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Salmonella
/
Bovinos
/
Contaminación de Alimentos
/
Escherichia coli O157
/
Escherichia coli
Tipo de estudio:
Etiology_studies
/
Prognostic_studies
/
Risk_factors_studies
Límite:
Animals
Idioma:
En
Revista:
J Food Prot
Año:
2009
Tipo del documento:
Article
País de afiliación:
Estados Unidos