Pearson A D, Greenwood M H, Feltham R K, Healing T D, Donaldson J, Jones D M, Colwell R R
Department of Microbiology, United Medical & Dental School (London University), St. Thomas's Hospital, England.
Appl Environ Microbiol. 1996 Dec;62(12):4614-20. doi: 10.1128/aem.62.12.4614-4620.1996.
A study of Campylobacter jejuni on a broiler chicken farm between 1989 and 1994 gave an estimated isolation rate of 27% (3,304 of 12,233) from a 0.9% sample of 1.44 million broiler chickens from six to eight sheds over 32 consecutive rearing flocks comprising 251 broiler shed flocks. During the study, C. jejuni was found in 35.5% of the 251 shed flocks but only 9.2% (23 of 251) had Campylobacter isolates in successive flocks, with 9 of those 23 sheds having the same serotype between consecutive flocks, indicating a low level of transmission between flocks. Analysis of a systematic sample of 484 of 3,304 (14.6%) C. jejuni isolates showed that 85% were of 10 serotype complexes but 58% were of 3 serotype complexes, indicating a high degree of strain similarity throughout the entire study. The three commonest types were detected in 8 of 32 flocks during the 5-year study period, suggesting an intermittent common external Campylobacter source. This hypothesis was tested by a retrospective cohort analysis of C. jejuni rates and types by reference to hatchery supplier of the 1-day-old chicks. Isolation rates of C. jejuni and frequency distribution of types were determined in 6-week-old broiler chickens identified by the hatchery supplying the original chicks. The isolation rate of C. jejuni in broilers, supplied by hatchery A, was 17.6%, compared to 42.9% (P < 0.0001) for broilers reared from chicks supplied by hatchery B. In two instances, when both hatcheries were used to stock the same farm flock, Campylobacter isolates were found only in those sheds with chicks supplied by hatchery B. Thus, the frequency distribution of Campylobacter types for chickens supplied by the two hatcheries over the 5-year period showed marked dissimilarity. These findings suggest that the isolation rate and type of Campylobacter isolates in broiler chickens was associated with the hatchery supplying chicks. The lack of diversity of types and the intermittent high positivity of sheds is evidence for a common source of C. jejuni introduced by vertical transmission rather than contamination at the hatchery or during transportation.
1989年至1994年期间，对一个肉鸡养殖场空肠弯曲菌的一项研究表明，在来自6至8个鸡舍、连续32批饲养鸡群（共251个肉鸡鸡舍批次）的144万只肉鸡中抽取0.9%的样本，估计分离率为27%（12233只中有3304只）。在研究期间，在251个鸡舍批次中有35.5%发现了空肠弯曲菌，但只有9.2%（251个中有23个）在连续批次中分离出弯曲菌，其中23个鸡舍中有9个在连续批次中具有相同的血清型，表明鸡群间的传播水平较低。对3304株空肠弯曲菌中的484株（14.6%）进行系统抽样分析表明，85%属于10种血清型复合物，但58%属于3种血清型复合物，表明在整个研究过程中菌株相似性程度较高。在为期5年的研究期间，32个鸡群中有8个检测到三种最常见的类型，提示存在间歇性的共同外部弯曲菌来源。通过参照1日龄雏鸡的孵化场供应商对空肠弯曲菌的分离率和类型进行回顾性队列分析来验证这一假设。在由提供原始雏鸡的孵化场确定的6周龄肉鸡中测定空肠弯曲菌分离率和类型的频率分布。由孵化场A供应的肉鸡中空肠弯曲菌的分离率为17.6%，而由孵化场B供应的雏鸡饲养的肉鸡中该分离率为42.9%（P<0.0001）。有两次，当两个孵化场都用于为同一个农场鸡群供雏时，仅在那些由孵化场B供应雏鸡的鸡舍中发现了弯曲菌分离株。因此，两个孵化场供应的鸡在5年期间弯曲菌类型的频率分布显示出明显差异。这些发现表明，肉鸡中空肠弯曲菌的分离率和分离株类型与供应雏鸡的孵化场有关。类型缺乏多样性以及鸡舍间歇性高阳性率证明空肠弯曲菌的共同来源是通过垂直传播引入，而非在孵化场或运输过程中受到污染。
