Food Microbiology and Safety Laboratory, Department of Food Science, Faculty of Agriculture, Mu'tah University, Karak, Jordan, 71610.
J Food Prot. 2010 Mar;73(3):535-40. doi: 10.4315/0362-028x-73.3.535.
The objective of the present study was to investigate the incidence and contamination levels of different Listeria monocytogenes serovars in ready-to-eat meat products (RTE-MP) collected from different outlets and processing plants in Jordan in order (i) to provide information to Jordanian health authorities on the incidence of L. monocytogenes in RTE-MP sold and consumed in Jordan and (ii) to ascertain the risks of these products for consumers. Two hundred forty RTE-MP samples, 120 beef and 120 poultry, were analyzed. European International Organization for Standardization (EN ISO) 11290-1 and -2 standard protocols were used for detection and enumeration of L. monocytogenes. The identity of suspected L. monocytogenes was confirmed using PCR. Three Listeria spp., L. monocytogenes, L. innocua, and L. welshimeri, were isolated. L. innocua and L. welshimeri were the most and least frequently isolated with 56 and 36 samples, respectively. L. monocytogenes was isolated from 41 samples (17.1%): 23 from beef and 18 from poultry samples. The contamination levels of L. monocytogenes were <or=100 CFU/g in 97.5% (40 samples) of the positive samples. Only one beef sample with a count of >100 CFU/g was found. The L. monocytogenes strains isolated fell into two serotypes (1 and 4) and four different serovars (1/2a, 1/2b, 1/2c, and 4b).
本研究旨在调查约旦不同销售点和加工厂生产的即食肉类产品（RTE-MP）中不同李斯特菌血清型的发生率和污染水平，目的在于：(i) 为约旦卫生当局提供约旦销售和消费的 RTE-MP 中李斯特菌的发生率信息；(ii) 确定这些产品对消费者的风险。共分析了 240 份 RTE-MP 样本，其中 120 份来自牛肉，120 份来自禽肉。采用欧洲国际标准化组织（EN ISO）11290-1 和 -2 标准方案来检测和计数李斯特菌。使用 PCR 来确认疑似李斯特菌的身份。分离出三种李斯特菌，即李斯特菌、无害李斯特菌和威尔斯李斯特菌。无害李斯特菌和威尔斯李斯特菌的分离频率最高和最低，分别为 56 份和 36 份。41 份样本（17.1%）中分离出李斯特菌：23 份来自牛肉样本，18 份来自禽肉样本。97.5%（40 个样本）的阳性样本中李斯特菌的污染水平<或=100 CFU/g。仅发现一份牛肉样本的计数>100 CFU/g。分离出的李斯特菌株分为两种血清型（1 和 4）和四种不同的血清型（1/2a、1/2b、1/2c 和 4b）。
