Microbiological quality and antimicrobial resistance of Escherichia coli and Staphylococcus aureus isolated from conventional and organic �Arzuacutea-Ulloa� cheese
- Miranda, J.M.
- Mondragón, A.
- Vázquez Belda, Beatriz Isabel
- Fente Sampayo, Cristina A.
- Cepeda, A.
- Franco Abuín, Carlos Manuel
ISSN: 1947-6337, 1947-6345
Ano de publicación: 2009
Volume: 7
Número: 2
Páxinas: 103-110
Tipo: Artigo
Outras publicacións en: CyTA: Journal of food
Resumo
The presence of Escherichia coli, Staphylococcus aureus, Listeria monocytogenes and Salmonella spp. was tested in 184 cheese samples included in the Protected Designation of Origin "Arz a-Ulloa". From these samples, 57 were raw-milk conventional cheese (RCC), 67 were pasteurized-milk conventional cheese (PCC) and the remaining 60 were pasteurized-milk organic cheese (POC). From these samples, a total of 287 E. coli and 281 S. aureus isolates were analyzed by an agar disk diffusion assay for their resistance to 11 antimicrobial agents. No significant differences were seen in microbiological general acceptance according to European Regulation 2073/2005. Only L. monocytogenes showed unsatisfactorily high levels in RCC samples as compared to PCC (P = 0.0334) and POC (P = 0.0138) samples. Although it was found that both E. coli and S. aureus isolated from POC samples showed lower resistance to some antimicrobials than isolates from RCC and/or PCC, for other antimicrobials higher resistance rates were found for POC isolates than conventional ones. Thus, the differences in antimicrobial resistance were too ambiguous to recommend a higher use of antimicrobials in conventional dairy herds than in organic ones.