Fecal Shedding of Campylobacter and Arcobacter spp. in Dairy Cattle

Campylobacter jejuni, Campylobacter coli, and Arcobacter spp. were detected in feces of healthy dairy cows by highly specific multiplex-PCR assays. For C. jejuni, at this one-time sampling, cows from 80.6% of farm operations (n = 31) and 37.7% of individual dairy cattle fecal samples (n = 2,085) were positive. Farm management factors were correlated with prevalence in herds in which >25% of cows were positive for C. jejuni. Statistical significance was set at a P of 0.20. Using these criteria, application of manure with broadcast spreaders (P = 0.17), feeding of whole cottonseed or hulls (P = 0.17) or alfalfa (P = 0.15), and accessibility of feed to birds (P = 0.17) were identified as possible risk factors for C. jejuni infection. C. coli was detected in at least one animal in 19.4% of operations and 1.8% of individual cows (n = 2,085). At the herd level, use of broadcaster spreaders was not a risk factor for C. coli infection. For Arcobacter, cows from 71% of dairy operations (n = 31) and 14.3% of individual dairy cattle fecal samples (n = 1,682) were positive. At the herd level, for Arcobacter spp., feeding of alfalfa (P = 0.11) and use of individual waterers (P = 0.19) were protective. This is the first description of Arcobacter spp. in clinically healthy dairy cattle and the first attempt to correlate their presence with C. jejuni.

本研究通过高特异性多重聚合酶链式反应（multiplex-PCR）检测法，在健康泌乳奶牛的粪便样本中检出了空肠弯曲杆菌（Campylobacter jejuni）、结肠弯曲杆菌（Campylobacter coli）以及弓形杆菌属（Arcobacter spp.）。针对空肠弯曲杆菌，本次单次采样结果显示，31个受访养殖场中80.6%的牛场均检出阳性奶牛，且2085份个体泌乳奶牛粪便样本中37.7%呈阳性。针对空肠弯曲杆菌阳性率高于25%的牛群，本研究分析了养殖管理因素与该菌流行率的关联情况，并设定统计显著性阈值为P=0.20。基于此判定标准，经撒肥机施用粪肥（P=0.17）、饲喂全棉籽或棉籽壳（P=0.17）或苜蓿（P=0.15），以及饲料可被鸟类接触（P=0.17）被确定为空肠弯曲杆菌感染的潜在风险因素。19.4%的受访养殖场至少检出1头结肠弯曲杆菌阳性奶牛，2085份个体奶牛粪便样本中阳性率为1.8%。在牛群层面，撒肥机的使用并非结肠弯曲杆菌感染的风险因素。针对弓形杆菌属，31个受访养殖场中71%的牛场均检出阳性奶牛，1682份个体泌乳奶牛粪便样本中14.3%呈阳性。在牛群层面，饲喂苜蓿（P=0.11）及使用个体饮水器（P=0.19）为弓形杆菌属感染的保护性因素。本研究首次在临床健康的泌乳奶牛中检出弓形杆菌属，同时首次尝试将该菌的检出情况与空肠弯曲杆菌的感染状态进行关联分析。