Department of Population Health, College of Veterinary Medicine, The University of Georgia, Athens, GA 30602, USA.
Appl Environ Microbiol. 2010 Dec;76(23):7820-5. doi: 10.1128/AEM.01320-10. Epub 2010 Oct 1.
While measures to control carcass contamination with Salmonella at the processing plant have been implemented with some success, on-farm interventions that reduce Salmonella prevalence in meat birds entering the processing plant have not translated well on a commercial scale. We determined the impact of Salmonella vaccination on commercial poultry operations by monitoring four vaccinated and four nonvaccinated breeder (parental) chicken flocks and comparing Salmonella prevalences in these flocks and their broiler, meat bird progeny. For one poultry company, their young breeders were vaccinated by using a live-attenuated Salmonella enterica serovar Typhimurium vaccine (Megan VAC-1) followed by a killed Salmonella bacterin consisting of S. enterica serovar Berta and S. enterica serovar Kentucky. The other participating poultry company did not vaccinate their breeders or broilers. The analysis revealed that vaccinated hens had a lower prevalence of Salmonella in the ceca (38.3% versus 64.2%; P < 0.001) and the reproductive tracts (14.22% versus 51.7%; P < 0.001). We also observed a lower Salmonella prevalence in broiler chicks (18.1% versus 33.5%; P < 0.001), acquired from vaccinated breeders, when placed at the broiler farms contracted with the poultry company. Broiler chicken farms populated with chicks from vaccinated breeders also tended to have fewer environmental samples containing Salmonella (14.4% versus 30.1%; P < 0.001). There was a lower Salmonella prevalence in broilers entering the processing plants (23.4% versus 33.5%; P < 0.001) for the poultry company that utilized this Salmonella vaccination program for its breeders. Investigation of other company-associated factors did not indicate that the difference between companies could be attributed to measures other than the vaccination program.
虽然在加工厂控制沙门氏菌污染胴体的措施已经取得了一些成功，但在农场减少进入加工厂的肉禽中沙门氏菌流行的干预措施在商业规模上并没有很好地转化。我们通过监测四个接种疫苗和四个未接种疫苗的种鸡（亲代）鸡群，比较这些鸡群及其肉鸡、肉禽后代中的沙门氏菌流行率，来确定沙门氏菌疫苗接种对商业家禽养殖的影响。对于一家家禽公司，他们的年轻种鸡使用减毒鼠伤寒沙门氏菌血清型 Typhimurium活疫苗（Megan VAC-1）进行接种，然后使用包含沙门氏菌血清型 Berta 和沙门氏菌血清型 Kentucky 的灭活沙门氏菌菌苗进行加强接种。另一家参与的家禽公司没有对其种鸡或肉鸡进行接种。分析表明，接种疫苗的母鸡盲肠（38.3%比 64.2%；P < 0.001）和生殖道（14.22%比 51.7%；P < 0.001）中的沙门氏菌流行率较低。我们还观察到，从接种疫苗的种鸡获得的肉鸡雏鸡的沙门氏菌流行率较低（18.1%比 33.5%；P < 0.001），这些雏鸡被安置在与该家禽公司签订合同的肉鸡养殖场。从接种疫苗的种鸡中繁殖的肉鸡养殖场的环境样本中沙门氏菌的含量也较低（14.4%比 30.1%；P < 0.001）。对于使用这种沙门氏菌疫苗接种计划的家禽公司，进入加工厂的肉鸡的沙门氏菌流行率较低（23.4%比 33.5%；P < 0.001）。对其他与公司相关因素的调查表明，两家公司之间的差异不能归因于疫苗接种计划以外的措施。
