Department for Food and Environmental Safety, Veterinary Laboratories Agency-Weybridge, Addlestone, Surrey, United Kingdom.
Appl Environ Microbiol. 2011 Jan;77(1):98-107. doi: 10.1128/AEM.01388-10. Epub 2010 Oct 29.
Improved understanding of the ecology and epidemiology of Campylobacter in the poultry farm environment is key to developing appropriate farm-based strategies for preventing flock colonization. The sources of Campylobacter causing broiler flock colonization were investigated on one poultry farm and its environment, from which samples were obtained on three occasions during each of 15 crop cycles. The farm was adjacent to a dairy farm, with which there was a shared concreted area and secondary entrance. There was considerable variation in the Campylobacter status of flocks at the various sampling times, at median ages of 20, 26, and 35 days, with 3 of the 15 flocks remaining negative at slaughter. Campylobacters were recoverable from various locations around the farm, even while the flock was Campylobacter negative, but the degree of environmental contamination increased substantially once the flock was positive. Molecular typing showed that strains from house surroundings and the dairy farm were similar to those subsequently detected in the flock and that several strains intermittently persisted through multiple crop cycles. The longitudinal nature of the study suggested that bovine fecal Campylobacter strains, initially recovered from the dairy yard, may subsequently colonize poultry. One such strain, despite being repeatedly recovered from the dairy areas, failed to colonize the concomitant flock during later crop cycles. The possibility of host adaptation of this strain was investigated with 16-day-old chickens experimentally exposed to this strain naturally present in, or spiked into, bovine feces. Although the birds became colonized by this infection model, the strain may preferentially infect cattle. The presence of Campylobacter genotypes in the external environment of the poultry farm, prior to their detection in broiler chickens, confirms the horizontal transmission of these bacteria into the flock and highlights the risk from multispecies farms.
提高对养鸡场环境中弯曲杆菌的生态学和流行病学的认识，是制定适当农场策略以防止鸡群定植的关键。在一个养鸡场及其环境中，对引起肉鸡群定植的弯曲杆菌的来源进行了调查，在 15 个作物周期的每个周期中，从三个不同时间点采集了样本。该农场与一个奶牛场相邻，有一个共用的混凝土区域和一个次要入口。在各个采样时间，鸡群的弯曲杆菌状况存在相当大的差异，中位数年龄分别为 20、26 和 35 天，15 个鸡群中有 3 个在屠宰时仍为阴性。即使在鸡群为弯曲杆菌阴性时，也可以从养鸡场周围的各个地方回收弯曲杆菌，但一旦鸡群呈阳性，环境污染程度就会大大增加。分子分型表明，来自房屋周围和奶牛场的菌株与随后在鸡群中检测到的菌株相似，并且有几个菌株在多个作物周期中间歇性持续存在。该研究的纵向性质表明，最初从奶牛场回收的牛粪便弯曲杆菌菌株可能随后定植家禽。其中一个菌株尽管反复从奶牛区回收，但在以后的作物周期中未能定植伴随的鸡群。通过 16 日龄的鸡实验暴露于天然存在于牛粪便中的或添加到牛粪便中的该菌株，研究了该菌株的宿主适应性的可能性。尽管该感染模型使鸟类定植，但该菌株可能更倾向于感染牛。在肉鸡中检测到弯曲杆菌基因型之前，这些基因型已经存在于养鸡场的外部环境中，这证实了这些细菌通过水平传播进入鸡群，并突出了多物种农场的风险。
