RESUMO
The automated method for enumeration of Escherichia coli, TEMPO EC, in foods uses a dehydrated culture medium and enumeration card containing 48 wells across three different dilutions for the automatic determination of the most probable number (MPN). The alternative method was compared in a multilaboratory collaborative study to AOAC Official Method 966.24. Six food types were artificially contaminated with E. coli: raw ground beef, bagged lettuce, cooked chicken, pasteurized crabmeat, frozen green beans, and pasteurized whole milk. All foods were analyzed for E. coli counts by 11 collaborating laboratories throughout the United States. Test portions from the six food types each contaminated at four different contamination levels were evaluated. The study demonstrated that the TEMPO EC method is a reliable, automated assay for the enumeration of E. coli in foods.
Assuntos
Contagem de Colônia Microbiana/métodos , Escherichia coli/metabolismo , Contaminação de Alimentos , Microbiologia de Alimentos , Animais , Automação , Bovinos , Galinhas/microbiologia , Análise de Alimentos , Laboratórios/normas , Carne/microbiologia , Reprodutibilidade dos Testes , Projetos de Pesquisa , Alimentos Marinhos/microbiologia , Verduras/microbiologiaRESUMO
The automated system for enumeration of total viable count (TVC) in foods, TEMPO TVC, uses a dehydrated culture medium and an enumeration card containing 48 wells across 3 different dilutions for the automatic determination of the most probable number (MPN). The alternative method was compared in a multilaboratory collaborative study to AOAC Method 966.23 for determination of aerobic plate count for nondairy products and the Standard Methods for the Examination of Dairy Products (SMEDP) Standard Plate Count for dairy products. Five food types, raw ground beef, raw ground chicken, cooked whitefish fillets, bagged lettuce, and milk, were analyzed for TVC by 14 collaborating laboratories throughout the United States and Canada. Three lots of naturally contaminated food products representing a wide range of counts were tested for each of the 5 food types. The study demonstrated that the overall repeatability, reproducibility, and mean log counts of the TEMPO TVC method were statistically comparable to those of the 2 standard methods at the 5% level.
