Klaeboe Halvdan, Rosef Olav, Fortes Esther, Wiedmann Martin
Department of Environmental and Health Studies, Telemark University College, Telemark, Norway.
Int J Environ Health Res. 2006 Oct;16(5):375-83. doi: 10.1080/09603120600869406.
The purpose of this study was to use automated ribotyping procedure to track Listeria monocytogenes transmission in the cold smoked fish production chain and to characterize L. monocytogenes subtypes associated with the salmon processing industry. A total of 104 isolates, which had previously been obtained from a raw fish slaughter and processing plant (plant B) and an adjacent, downstream, salmon smoking operation (plant A), were characterized. These isolates had been obtained through a longitudinal study on Listeria presence, which covered a 31-week period, in both plants. Isolates had been obtained from samples taken from different machinery used throughout the production process. In addition, six isolates obtained from products produced in plant A two years after the initial study were included, so that a total of 110 isolates were characterized. Automated ribotyping was performed using both the restriction enzymes EcoRI and PvuII to increase the discriminatory power. The 110 L. monocytogenes isolates could be divided into 11 EcoRI ribotypes; PvuII ribotype data yielded multiple subtypes within 7 EcoRI ribotypes for a total of 21 subtypes based on both EcoRI and PvuII ribotyping. A total of three EcoRI ribotypes (DUP-1023C, DUP-1045B, and DUP-1053E) were isolated at multiple sampling times from both plants. In addition, one subtype (DUP-1053B) was isolated at multiple sampling times in only plant A, the salmon smoking operation. These data not only support that L. monocytogenes can persist throughout the salmon production system, but also showed that L. monocytogenes may be transmitted between slaughter and smoking operations or may be unique to smoking operations. While the majority of subtypes isolated have been rarely or never linked to human listeriosis cases, some subtypes have previously caused human listeriosis outbreaks and cases. Molecular subtyping thus is critical to identify L. monocytogenes transmission and niches in order to allow design and implementation of control strategies at the appropriate stage of production and in order to reduce the prevalence of L. monocytogenes linked to human disease.
本研究的目的是使用自动化核糖体分型程序追踪冷熏鱼生产链中单核细胞增生李斯特菌的传播，并对与鲑鱼加工业相关的单核细胞增生李斯特菌亚型进行特征分析。对总共104株分离株进行了特征分析，这些分离株先前从一家生鱼屠宰和加工厂（工厂B）以及相邻的下游鲑鱼烟熏加工厂（工厂A）获得。这些分离株是通过一项关于李斯特菌存在情况的纵向研究获得的，该研究在两家工厂覆盖了31周的时间。分离株取自整个生产过程中使用的不同机器的样本。此外，纳入了在初始研究两年后从工厂A生产的产品中获得的6株分离株，因此总共对110株分离株进行了特征分析。使用限制性内切酶EcoRI和PvuII进行自动化核糖体分型，以提高鉴别力。110株单核细胞增生李斯特菌分离株可分为11种EcoRI核糖体分型；基于EcoRI和PvuII核糖体分型，PvuII核糖体分型数据在7种EcoRI核糖体分型中产生了多个亚型，总共21个亚型。在两个工厂的多个采样时间共分离出三种EcoRI核糖体分型（DUP-1023C、DUP-1045B和DUP-1053E）。此外，仅在鲑鱼烟熏加工厂工厂A的多个采样时间分离出一种亚型（DUP-1053B）。这些数据不仅支持单核细胞增生李斯特菌可在整个鲑鱼生产系统中持续存在，还表明单核细胞增生李斯特菌可能在屠宰和烟熏操作之间传播，或者可能是烟熏操作所特有的。虽然分离出的大多数亚型很少或从未与人类李斯特菌病病例相关联，但一些亚型此前曾导致人类李斯特菌病暴发和病例。因此，分子分型对于识别单核细胞增生李斯特菌的传播和生态位至关重要，以便在生产的适当阶段设计和实施控制策略，并降低与人类疾病相关的单核细胞增生李斯特菌的流行率。
