Centro para la Calidad de los Alimentos, INIA, José Tudela s/n, 42004 Soria, Spain.
Departamento de Tecnología de Alimentos, INIA, Carretera de La Coruña Km 7, 28040 Madrid, Spain.
Food Microbiol. 2020 Dec;92:103581. doi: 10.1016/j.fm.2020.103581. Epub 2020 Jun 28.
The majority of cases of listeriosis are associated with the consumption of contaminated food. Some strains of Listeria monocytogenes can persist over months or years in meat processing plants increasing the risk of product contamination. The presence of L. monocytogenes was examined in 10 dry-cured ham processing facilities. A total of 1801 samples were collected from environment and equipment, during processing (1095) and after cleaning and disinfection (706). These samples were taken from non-food contact (736) and food contact (1065) surfaces. In addition, 204 samples from ham surfaces were also analysed. Prevalence varied from 6% to 34% among facilities, and was higher during processing than after cleaning and disinfection (24.8% vs 11.0%) and from non-food than from food contact surfaces (22.6% vs 17.4%). L. monocytogenes serotype 1/2a was predominant (53.9%), followed by 1/2c (26.0%) and 1/2b (15.3%) and less frequently 4b (4.8%). A total of 142 different pulsotypes were registered. Potential persistent L.monocytogenes strains were isolated in 9 out the 10 facilities, with no more than 6 pulsotypes in a given plant. Two pulsotypes were common in different installations, detected before and after cleaning and disinfection, highlighting the importance of monitoring the presence of this pathogen in dry-cured ham processing environments.
李斯特菌病的大多数病例与食用受污染的食物有关。某些单核细胞增生李斯特菌菌株可以在肉类加工工厂中持续存在数月或数年，增加了产品污染的风险。在 10 个干腌火腿加工设施中检查了单核细胞增生李斯特菌的存在。从环境和设备、加工过程中（1095 个）以及清洁和消毒后（706 个）共采集了 1801 个样本。这些样本取自非食品接触面（736 个）和食品接触面（1065 个）。此外，还分析了 204 个来自火腿表面的样本。设施之间的流行率从 6%到 34%不等，且加工过程中的流行率高于清洁和消毒后（24.8%比 11.0%），非食品接触面的流行率高于食品接触面（22.6%比 17.4%）。1/2a 血清型李斯特菌占优势（53.9%），其次是 1/2c（26.0%）和 1/2b（15.3%），4b 型较少见（4.8%）。共登记了 142 种不同的脉冲型。在 10 个设施中的 9 个中分离到了潜在的持续存在的李斯特菌菌株，每个工厂的脉冲型不超过 6 种。两种脉冲型在不同的装置中都很常见，在清洁和消毒前后都有检测到，这突出了监测干腌火腿加工环境中这种病原体存在的重要性。
