Journal of Food Safety · 1999 · 34 citations · 21 references
AgricultureFood ScienceMicrobiologyCheese ScienceFood MicrobiologyFood SafetyCheese MicrobiologyCheese RipeningFoodborne Pathogen DetectionMicrobial ContaminationMicrobial Spoilage Of CheesePathogen Detection In FoodsCheese Ripening MicrobiologyCheese Spoilage MicrobiologyFoodborne Pathogens In CheeseListeria DetectionListeria Monocytogenes ContaminationMicrobial Diversity In CheesePasteurized Milk ContaminationStreet Vendors
ABSTRACT The presence of Listeria was investigated in ripened cheeses (Chihuahua, Manchego) and fresh cheese (Panela) from street vendors and retail stores in Mexico City. Cheeses were tested for Listeria, pH, NaCl, moisture and fat. Listeria selective cold enrichment was used to recover Listeria from positive samples. Fresh cheese had the lowest pH and NaCl contents and the highest moisture Chihuahua and Manchego cheeses made with pasteurized milk were negative for Listeria. Panela cheese samples were the most contaminated. The presence of Listeria was 65% in fresh cheeses: Listeria murrayi 20% , Listeria inoccua 15% , Listeria grayi 15%, and Listeria monocytogenes 15%. L. monocytogenes serotypes 1/2a, 1/2b and 4b were isolated from positive samples.
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