Allen V M, Weaver H, Ridley A M, Harris J A, Sharma M, Emery J, Sparks N, Lewis M, Edge S
Department of Clinical Veterinary Science, University of Bristol, Langford, North Somerset BS40 5DU, UK.
J Food Prot. 2008 Feb;71(2):264-70. doi: 10.4315/0362-028x-71.2.264.
The practice of partial depopulation or thinning (early removal of a portion of birds from a commercial broiler flock) is a reported risk factor for Campylobacter colonization of residual birds because of the difficulty in maintaining biosecurity during the thinning process. The effect of this practice was studied in detail for 51 target flocks, each at a different growing farm belonging to one of seven major poultry companies throughout the United Kingdom. On 21 of these farms, the target flock was already colonized by Campylobacter, and at slaughter all cecal samples examined were positive, with a mean of 8 log CFU/g. An additional 27 flocks became positive within 2 to 6 days of the start of thinning and had similarly high levels of cecal carriage at slaughter. Just before the thinning process, Campylobacter was isolated frequently from the farm driveways, transport vehicles, equipment, and personnel. Strains from seven farms on which flocks became colonized after thinning were examined by pulsed-field gel electrophoresis typing. An association was found between strains occurring at specific sampling sites and those isolated subsequently from the thinned flocks. The results indicated that particular strains had spread from one farm to another when the farms were jointly owned by the same company and employed the same bird-catching teams and/or vehicles. These results highlight the need for better hygiene control in relation to catching equipment and personnel and more effective cleaning and disinfection of vehicles and bird-transport crates.
部分种群减少或稀疏处理（即从商业肉鸡群中提前移除一部分鸡）的做法据报道是残留鸡群感染弯曲杆菌的一个风险因素，因为在稀疏处理过程中难以维持生物安全。对英国七家主要家禽公司之一所属不同养殖农场的51个目标鸡群详细研究了这种做法的影响。在其中21个农场，目标鸡群已被弯曲杆菌定植，屠宰时所有检测的盲肠样本均呈阳性，平均含量为每克8 log CFU。另外27个鸡群在稀疏处理开始后的2至6天内变为阳性，屠宰时盲肠带菌水平同样很高。就在稀疏处理前，在农场车道、运输车辆、设备和人员中频繁分离出弯曲杆菌。对稀疏处理后鸡群定植的七个农场的菌株进行了脉冲场凝胶电泳分型检测。发现在特定采样点出现的菌株与随后从稀疏处理鸡群中分离出的菌株之间存在关联。结果表明，当农场由同一家公司共同拥有并使用相同的抓鸡团队和/或车辆时，特定菌株会从一个农场传播到另一个农场。这些结果凸显了在抓鸡设备和人员方面加强卫生控制以及对车辆和鸡运输箱进行更有效清洁和消毒的必要性。
