Lundén Janne M, Autio Tiina J, Korkeala Hannu J
Department of Food and Environmental Hygiene, Faculty of Veterinary Medicine, University of Helsinki, Finland.
J Food Prot. 2002 Jul;65(7):1129-33. doi: 10.4315/0362-028x-65.7.1129.
The possibility of the transfer of persistent Listeria monocytogenes contamination from one plant to another with a dicing machine was evaluated, and possible reasons for persistent contamination were analyzed. A dicing machine that diced cooked meat products was transferred from plant A to plant B and then to plant C. After the transfer of the dicing machine, L. monocytogenes PFGE type I, originally found in plant A, was soon also found in plants B and C. This L. monocytogenes PFGE type I caused persistent contamination of the dicing lines in plants B and C. The persistent L. monocytogenes strain and three nonpersistent L. monocytogenes strains found in the dicing line of plant C were tested for adherence to stainless steel surfaces and minimal inhibitory concentrations of a quaternary ammonium compound and sodium hypochlorite, disinfectants widely used in the dicing lines. The persistent strain showed significantly higher adherence to stainless steel surfaces than did the nonpersistent strains. The minimal inhibitory concentrations of sodium hypochlorite were similar for all strains, and the minimal inhibitory concentrations of the quaternary ammonium compound for three of the L. monocytogenes PFGE types, including the persistent PFGE type, were high. All persistent L. monocytogenes PFGE type I isolates were found in an area with high hygienic standards, with the dicing machine being the first point of contamination. These observations show that the dicing machine sustained the contamination and suggest that the dicing machine transferred the persistent L. monocytogenes PFGE type from one plant to another.
评估了用切丁机将持续性单核细胞增生李斯特菌污染从一个工厂转移到另一个工厂的可能性，并分析了持续性污染的可能原因。一台用于切割熟肉制品的切丁机从工厂A转移到工厂B，然后再转移到工厂C。在切丁机转移后，最初在工厂A发现的单核细胞增生李斯特菌PFGE I型很快也在工厂B和C中被发现。这种单核细胞增生李斯特菌PFGE I型导致了工厂B和C中切丁生产线的持续性污染。对在工厂C的切丁生产线中发现的持续性单核细胞增生李斯特菌菌株和三种非持续性单核细胞增生李斯特菌菌株进行了不锈钢表面黏附性测试以及季铵化合物和次氯酸钠（切丁生产线中广泛使用的消毒剂）的最低抑菌浓度测试。持续性菌株对不锈钢表面的黏附性明显高于非持续性菌株。所有菌株的次氯酸钠最低抑菌浓度相似，包括持续性PFGE型在内的三种单核细胞增生李斯特菌PFGE型的季铵化合物最低抑菌浓度较高。所有持续性单核细胞增生李斯特菌PFGE I型分离株都在卫生标准较高的区域被发现，切丁机是第一个污染点。这些观察结果表明，切丁机维持了污染，并表明切丁机将持续性单核细胞增生李斯特菌PFGE型从一个工厂转移到了另一个工厂。
