Husu J R
National Veterinary Institute, Department of Bacteriology and Serology, Helsinki, Finland.
Zentralbl Veterinarmed B. 1990 Jun;37(4):276-82. doi: 10.1111/j.1439-0450.1990.tb01059.x.
Seasonal variation in the fecal shedding of Listeria spp. in dairy cattle was examined by collecting a total of 3,878 fecal samples during a period of two years. The prevalences of Listeria spp. and L. monocytogenes were higher during the indoor season (12.7% and 9.2%, respectively) than in samples collected from the animals on pasture (5.3% and 3.1%, respectively). The highest frequencies of Listeria spp. (19.4%) and L. monocytogenes (16.1%) were detected in December. Listeriae were isolated from at least one of the dairy cows from 45.8% of the 249 herds examined. 2.9% of the 314 milk samples collected from the farm bulk tanks on 80 dairy farms on four different occasions yielded L. monocytogenes. The seasonal occurrence of these bacteria in milk reflected the frequencies of Listeria in the fecal material but not those in the main roughage used; grass silage and pasture grass. Fecal material is considered to be a potential source of contamination of raw milk by L. monocytogenes. Investigation of the numbers of viable Listeria organisms in different animal fodders is considered essential in further epidemiological studies of these bacteria.
通过在两年时间内总共采集3878份粪便样本，研究了奶牛粪便中李斯特菌属的季节性变化。李斯特菌属和单核细胞增生李斯特菌的流行率在室内饲养季节（分别为12.7%和9.2%）高于在牧场采集的样本（分别为5.3%和3.1%）。在12月检测到李斯特菌属（19.4%）和单核细胞增生李斯特菌（16.1%）的最高频率。在所检查的249个牛群中，45.8%的牛群至少有一头奶牛分离出李斯特菌。在四个不同场合从80个奶牛场的农场储奶罐中采集的314份牛奶样本中，2.9%检测出单核细胞增生李斯特菌。这些细菌在牛奶中的季节性出现反映了粪便中李斯特菌的频率，但与主要粗饲料（青贮草和牧草）中的频率无关。粪便被认为是生牛奶受单核细胞增生李斯特菌污染的潜在来源。在这些细菌的进一步流行病学研究中，调查不同动物饲料中李斯特菌活菌数量被认为至关重要。
