Mohammed Hussni O, Stipetic Korana, McDonough Patrick L, Gonzalez Ruben N, Nydam Daryl V, Atwill Edward R
Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, NY 14853, USA.
Am J Vet Res. 2009 Mar;70(3):383-8. doi: 10.2460/ajvr.70.3.383.
To elucidate the ecology of Listeria monocytogenes on dairy cattle farms by determining the prevalence of the organism in various samples.
Dairy cattle operations in central New York State.
A repeated cross-sectional study design was used. Various samples were obtained from cattle (feces, composite udder milk, and udders), their environment (silage, feed bunks, water troughs, and floor bedding), inline milk filters, and bulk tank milk from 50 dairy farms. Samples were tested for L monocytogenes by use of a PCR assay with 2 steps of bacterial enrichment. Data were analyzed with mixed-effect logistic regression to control for the potential clustering of L monocytogenes on particular farms.
L monocytogenes was detected in composite milk, udder swab samples, and fecal samples at prevalences of 13%, 19%, and 43%, respectively. There was no significant clustering of the pathogen by farm. Listeria monocytogenes was more common in samples obtained from cattle and the environment during winter and summer versus the fall. The prevalence of L monocytogenes was twice as high in samples obtained from feed bunks, water troughs, and bedding, compared with that in samples obtained from silage (65%, 66%, 55%, and 30%, respectively).
L monocytogenes was more prevalent in samples obtained from dairy cattle and their environment than in milk samples. Strategies to control the pathogen in dairy operations should focus on cow hygiene and sanitary milk harvesting on the farm.
通过测定各种样本中该菌的流行率，阐明纽约州中部奶牛场中单核细胞增生李斯特菌的生态学特征。
纽约州中部的奶牛养殖场。
采用重复横断面研究设计。从50个奶牛场的牛（粪便、混合乳房乳和乳房）、其环境（青贮饲料、饲料槽、水槽和垫料）、在线牛奶过滤器和贮奶罐牛奶中采集各种样本。通过使用经过两步细菌富集的聚合酶链反应（PCR）检测法对样本进行单核细胞增生李斯特菌检测。采用混合效应逻辑回归分析数据，以控制特定农场中单核细胞增生李斯特菌的潜在聚集情况。
在混合乳、乳房拭子样本和粪便样本中分别检测到单核细胞增生李斯特菌，流行率分别为13%、19%和43%。该病原体在各农场之间无明显聚集现象。与秋季相比，冬季和夏季从牛及其环境中采集的样本中单核细胞增生李斯特菌更为常见。与青贮饲料样本相比，从饲料槽、水槽和垫料中采集的样本中单核细胞增生李斯特菌的流行率高出两倍（分别为65%、66%、55%和30%）。
单核细胞增生李斯特菌在从奶牛及其环境中采集的样本中比在牛奶样本中更为普遍。奶牛场控制该病原体的策略应侧重于奶牛卫生和农场牛奶的卫生采集。
