Comparative Evaluation of Five Selective and Differential Media for the Detection and Enumeration of Coagulase-Positive Staphylococci in Foods.

摘要: Five selective media for the detection and enumeration of coagulase-positive staphylococci were evaluated their efficiency in recovery 17 strains from foods. They Staphylococcus Medium 110 (SM-110), tellurite-glycine-agar (TGA), egg-tellurite-glycine-pyruvate-agar (ETGPA), tellurite-egg-agar (TEA), tellurite-polymyxin-egg yolk-agar (TPEY). Statistical analysis by rank correlation method with which these recovered pure 24-hr Brain Heart Infusion cultures revealed following efficiencies descending order: (i) TPEY, (ii) ETGPA, (iii) TGA, (iv) TEA, (v) SM-110. Growth coagulase-negative cocci on showed approximate order inhibition to organisms: SM-110, TPEY. The appearance colonies various each medium was studied degree they could be confused strains. Nineteen food contaminants, including Proteus vulgaris, Bacillus sp., Escherichia coli, Erwinia fecal streptococci, others, also similarities ability grow media. influence five sterile homogenates (frozen chicken tuna pies, custard, smoked ham, raw whole egg) 1,500 enterotoxigenic (three strains) per milliliter determined statistical analysis. Three main effects (culture, media, food) three interactions (media food, cultures, culture) found significant. Recovery TPEY influenced less than other optimal eggs, ham. TGA well pie SM-110 TEA None outstanding recovering pie. recover ml foods presence 10 contaminating bacteria added at 0, 105, 106 levels analyzed statistically. Only factors significant under conditions—cultures, foods, interaction level contamination. Efficiency ETGPA not dependent upon decreased increases number contaminants. increased 105 level, but level. When Trypticase Soy Agar considered 100%, average percentage all experimental conditions determined.