Onizawa Emily, Westman Mark E, Bogema Daniel R, Deutscher Ania T, Eamens Kieran, Micallef Melinda L, McDonogh Tammy, Jenkins Cheryl
NSW Department of Primary Industries and Regional Development, Elizabeth Macarthur Agricultural Institute, Menangle, NSW 2568, Australia.
Sydney School of Veterinary Science, The University of Sydney, Sydney, NSW 2006, Australia.
Transbound Emerg Dis. 2025 Jun 4;2025:9937941. doi: 10.1155/tbed/9937941. eCollection 2025.
spp. are a significant cause of human foodborne illness globally, with ingestion of contaminated eggs a major vehicle for infection. serovar Enteritidis (. Enteritidis, SE) is the serovar most linked to egg-related foodborne salmonellosis in most developed countries. Until 2018, the Australian egg industry was considered free of SE. This report documents the diagnostic testing performed on samples from egg layer farms across New South Wales (NSW), Australia, as part of a SE outbreak response between 2018 and 2020. Testing was undertaken following a cluster of cases of SE infection in humans traced to the consumption of eggs originating from a single contaminated poultry farm. Quantitative real-time polymerase chain reaction (qPCR) testing was used to screen environmental and animal samples ( = 2058) from 29 different properties identified through contact tracing. Confirmatory bacterial culture ( = 717) was performed on any SE qPCR-positive samples and a subset of qPCR-negative and qPCR-inconclusive samples. In total, 13/29 (45%) of egg layer farms were SE-positive by qPCR testing, with 12/13 (92%) of these farms confirmed SE-positive by bacterial culture and serotyping. Both environmental and animal samples produced SE-positive results, in particular surface swabs, boot covers, feces, and eggs. When qPCR testing and bacterial culture were performed side-by-side, qPCR testing to detect SE compared to bacterial culture had sensitivity of 100% (43/43) and specificity of 94.1% (238/253; 95% confidence interval[CI] 91.4-96.8). SE isolates obtained during the outbreak were predominantly phage type (PT)1b and PT12. Whole genome sequencing (WGS) of SE isolates from 9 of 12 culture-positive properties confirmed that they were all sequence type 11, Clade B, and derived from a single source. As a result of rapid qPCR detection of SE on contaminated farms, appropriate biosecurity responses were implemented, and NSW commercial layer farms were again considered SE-free in August 2020. This report highlights the utility of high-throughput molecular testing for SE in outbreak situations.
沙门氏菌属是全球人类食源性疾病的一个重要病因，摄入受污染的鸡蛋是主要的感染途径。肠炎血清型沙门氏菌（Salmonella Enteritidis，SE）是大多数发达国家中与鸡蛋相关的食源性沙门氏菌病关联最紧密的血清型。直到2018年，澳大利亚的蛋鸡产业被认为没有SE。本报告记录了对澳大利亚新南威尔士州（NSW）蛋鸡养殖场样本进行的诊断检测，作为2018年至2020年SE疫情应对措施的一部分。检测是在一群人类SE感染病例被追溯到食用来自一个受污染家禽养殖场的鸡蛋之后进行的。采用定量实时聚合酶链反应（qPCR）检测对通过接触追踪确定的29个不同场所的环境和动物样本（n = 2058）进行筛查。对任何SE qPCR阳性样本以及一部分qPCR阴性和qPCR结果不确定的样本进行了确证性细菌培养（n = 717）。总共，29个蛋鸡养殖场中有13个（45%）通过qPCR检测呈SE阳性，其中13个养殖场中有12个（92%）通过细菌培养和血清分型确证为SE阳性。环境样本和动物样本均产生了SE阳性结果，特别是表面拭子、鞋套、粪便和鸡蛋。当同时进行qPCR检测和细菌培养时，与细菌培养相比，用于检测SE的qPCR检测灵敏度为100%（43/43），特异性为94.1%（238/253；95%置信区间[CI] 91.4 - 96.8）。疫情期间获得的SE分离株主要是噬菌体类型（PT）1b和PT12。对12个培养阳性场所中的9个场所的SE分离株进行全基因组测序（WGS）证实，它们均为序列型11，进化枝B，且源自单一来源。由于在受污染养殖场对SE进行了快速qPCR检测，实施了适当的生物安全应对措施，新南威尔士州的商业蛋鸡养殖场在2020年8月再次被认为没有SE。本报告强调了在疫情情况下对SE进行高通量分子检测的实用性。
