Sharma A, Erdman M M, Muñoz-Vargas L, Mollenkopf D F, Habing G G
The Ohio State University, Columbus, OH, USA.
National Veterinary Services Laboratories, Ames, IA, USA.
Zoonoses Public Health. 2018 Feb;65(1):e102-e112. doi: 10.1111/zph.12416. Epub 2017 Oct 30.
Every year, multiple outbreaks of salmonellosis in humans are linked to contact with mail-order chicks and ducks. The objective of this study was to describe the temporal changes in the prevalence of serovars, genotypes and antimicrobial resistance (AMR) phenotypes of non-typhoidal Salmonella (NTS) recovered from shipped boxes of mail-order hatchling poultry in the United States during 2013 to 2015. In each year, a sample of feed stores belonging to a single national chain participated in the study. The store employees submitted swabs or hatchling pads from hatchling boxes and shipment tracking information of the arriving boxes to the investigators. NTS was cultured from the samples and isolates were sent to the National Veterinary Services Laboratories (Ames, IA) for serotyping, pulsed-field gel electrophoresis (PFGE) and AMR phenotyping. The PFGE patterns of Salmonella serovars isolated from hatchling boxes were compared with those from human outbreaks of salmonellosis linked to live poultry contact. The box-level prevalence of NTS was significantly higher in 2015 compared to 2014. Also, the population of Salmonella serovars recovered in 2015 was more diverse and substantially different from those recovered in the previous two years. Of PFGE patterns recovered from hatchling boxes, seven distinct patterns in 2015, three in 2014 and four in 2013 were indistinguishable from the PFGE patterns of human outbreaks-associated strains in the respective years. Importantly, a significant positive correlation was found between the box-level prevalence of PFGE patterns and the number of human illnesses associated with the same patterns. Also, the proportion of multidrug-resistant isolates was higher in 2014 and 2015 compared to that in 2013. The results demonstrate that shipments of mail-order hatchling poultry are frequently contaminated with Salmonella genotypes indistinguishable from human outbreaks-associated strains each year, and control efforts at hatchery level are likely to have an important public health impact.
每年，人类中多次沙门氏菌病暴发都与接触邮购雏鸡和雏鸭有关。本研究的目的是描述2013年至2015年期间从美国邮购雏禽运输箱中回收的非伤寒沙门氏菌（NTS）血清型、基因型和抗菌药物耐药性（AMR）表型流行率的时间变化。每年，属于单一全国性连锁店的饲料店样本参与该研究。商店员工将来自孵化箱的拭子或孵化垫以及到达箱子的运输跟踪信息提交给调查人员。从样本中培养出NTS，并将分离株送至国家兽医服务实验室（爱荷华州埃姆斯）进行血清分型、脉冲场凝胶电泳（PFGE）和AMR表型分析。将从孵化箱中分离的沙门氏菌血清型的PFGE模式与与活禽接触相关的人类沙门氏菌病暴发中的模式进行比较。2015年NTS的箱子水平流行率显著高于2014年。此外，2015年回收的沙门氏菌血清型群体更加多样化，与前两年回收的群体有很大不同。从孵化箱中回收的PFGE模式中，2015年有7种不同模式，2014年有3种，2013年有4种，与各年份人类暴发相关菌株的PFGE模式无法区分。重要的是，发现PFGE模式的箱子水平流行率与相同模式相关的人类疾病数量之间存在显著正相关。此外，2014年和2015年多重耐药分离株的比例高于2013年。结果表明，每年邮购雏禽的运输经常被与人类暴发相关菌株无法区分的沙门氏菌基因型污染，孵化场层面的控制措施可能对公共卫生产生重要影响。
