Novoa Rama Estefanía, Bailey Matthew, Jones Deana R, Gast Richard K, Anderson Ken, Brar Jagpinder, Taylor Rhonda, Oliver Haley F, Singh Manpreet
1 Department of Poultry Science, University of Georgia , Athens, Georgia .
2 United States Department of Agriculture, Agricultural Research Service , Athens, Georgia .
Foodborne Pathog Dis. 2018 Aug;15(8):506-516. doi: 10.1089/fpd.2017.2404.
Husbandry practices for laying hens in commercial egg production is a topic of interest from a social, economic, and regulatory standpoint. Animal welfare concerns regarding the use of conventional cages have arisen and consumer perceptions of hen welfare have led to a higher demand for cage-free eggs. The aim of this study was to assess the impact of housing systems on prevalence, persistence, and antimicrobial resistance (AMR) of Campylobacter from laying hens and shell eggs. A total of 425 samples were collected over a 10-month period from the North Carolina Layer Performance and Management Test and Campylobacter isolates were identified by serological, biochemical, and molecular tests. Genetic variability was evaluated using pulsed-field gel electrophoresis (PFGE) and AMR testing was performed. Prevalence of Campylobacter spp. ranged from 11.1% in the enrichable cages to 19.7% in the conventional systems. A greater prevalence of Campylobacter was found in the fecal swab samples from free-range birds compared with those of birds housed in the more intensive housing systems (p > 0.05). Overall, 72 isolates were confirmed as Campylobacter spp. by PCR. More than 90% of the isolates (n = 66) were identified as Campylobacter jejuni, followed by Campylobacter coli (n = 6). C. jejuni isolates displayed high levels of resistance to tetracycline (67%). Genetic variability of Campylobacter was high, with more than 20 PFGE patterns identified. Pattern "a" comprised 42% of isolates from all housing systems and was also the most persistent. This study suggests that housing systems of laying hens used for commercial shell egg production may impact the rate of Campylobacter shedding by layers. Isolation rates and tetracycline resistance levels of this pathogen are still of concern, emphasizing the need for well-implemented biosecurity measures on the farm.
商业蛋鸡生产中蛋鸡的饲养管理实践，从社会、经济和监管角度来看都是一个备受关注的话题。人们对传统鸡笼的使用引发了动物福利方面的担忧，消费者对母鸡福利的认知导致对无笼蛋的需求增加。本研究的目的是评估饲养系统对蛋鸡和蛋中弯曲杆菌的流行率、持续性及抗菌药物耐药性（AMR）的影响。在10个月的时间里，从北卡罗来纳蛋鸡生产性能和管理测试中总共收集了425份样本，并通过血清学、生化和分子测试鉴定弯曲杆菌分离株。使用脉冲场凝胶电泳（PFGE）评估遗传变异性并进行AMR测试。弯曲杆菌属的流行率在可富集鸡笼中为11.1%，在传统系统中为19.7%。与饲养在集约化程度更高的鸡舍中的鸟类相比，散养鸟类粪便拭子样本中弯曲杆菌的流行率更高（p＞0.05）。总体而言，通过PCR确认有72株分离株为弯曲杆菌属。超过90%的分离株（n = 66）被鉴定为空肠弯曲杆菌，其次是大肠弯曲杆菌（n = 6）。空肠弯曲杆菌分离株对四环素显示出高水平耐药性（67%）。弯曲杆菌的遗传变异性很高，鉴定出20多种PFGE模式。模式“a”占所有饲养系统分离株的42%，也是最持久的模式。本研究表明，用于商业蛋生产的蛋鸡饲养系统可能会影响蛋鸡弯曲杆菌的排出率。该病原体的分离率和四环素耐药水平仍然令人担忧，这凸显了在农场实施完善生物安全措施的必要性。
