Bĕrziņs Aivars, Terentjeva Margarita, Korkeala Hannu
Department of Food and Environmental Hygiene, Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 66, FI-00014 Helsinki, Finland.
J Food Prot. 2009 Jun;72(6):1283-7. doi: 10.4315/0362-028x-72.6.1283.
Nine groups of different retail ready-to-eat vacuum-packaged meat products from 10 Baltic meat processing plants were analyzed for presence and numbers of Listeria monocytogenes at the end of shelf life. A total of 38 (18%) of 211 samples tested positive for L. monocytogenes serotype 1/2a (88%) or 1/2c (12%). The prevalence of L. monocytogenes in cold-smoked, sliced, vacuum-packaged beef and pork products (42%) was significantly higher than in cooked, sliced, vacuum-packaged meat products (0.8%) (P < 0.001). Enumeration of L. monocytogenes showed that 84% of the positive samples contained <100 CFU/g upon expiry of product shelf life. The numbers of L. monocytogenes exceeded 100 CFU/g only in cold-smoked, sliced, vacuum-packaged beef products. Identical pulsed-field gel electrophoresis types were recovered from different production lots of cold-smoked vacuum-packaged beef and pork products produced by the same meat processing plant, demonstrating L. monocytogenes contamination as a recurrent problem within one meat processing plant.
对来自10家波罗的海肉类加工厂的9组不同的零售即食真空包装肉类产品在保质期结束时进行了单核细胞增生李斯特菌的存在情况和数量分析。在211份样本中，共有38份（18%）检测出单核细胞增生李斯特菌1/2a血清型（88%）或1/2c血清型（12%）呈阳性。冷熏切片真空包装牛肉和猪肉产品中单核细胞增生李斯特菌的患病率（42%）显著高于熟切片真空包装肉类产品（0.8%）（P < 0.001）。单核细胞增生李斯特菌的计数显示，在产品保质期结束时，84%的阳性样本中每克含菌量<100 CFU。单核细胞增生李斯特菌数量超过100 CFU/g的情况仅出现在冷熏切片真空包装牛肉产品中。从同一肉类加工厂生产的不同批次冷熏真空包装牛肉和猪肉产品中分离出相同的脉冲场凝胶电泳类型，表明单核细胞增生李斯特菌污染是肉类加工厂内反复出现的问题。
