Subclinical avian hepatitis E virus infection in layer flocks in the United States
Subclinical avian hepatitis E virus infection in layer flocks in the United States
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DOI：
10.1016/j.tvjl.2015.10.014
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发表时间：
2015-12-01
影响因子：
2.2
通讯作者：
Opriessnig, Tanja
中科院分区：
文献类型：
--
作者：
Gerber, Priscilla F.;Trampel, Darrell W.;Opriessnig, Tanja
本研究的目的是确定自然感染的养鸡场的禽HEV感染模式。从美国中西部7个商业联产蛋场的62只鸡群中采集了310份血清样本和62份合并粪便样本，并对其进行了禽流感HEV循环检测。用荧光微珠免疫分析法（FMIA）检测血清样本是否存在抗禽流感HEV IgY抗体，该方法是为本研究开发的。使用已知暴露的鸡的存档样本（n = 96）验证了FMIA，并将其与基于相同捕获抗原的酶联免疫吸附试验（ELISA）获得的结果进行了比较。两种检测方法（kappa = 0.63）与FMIA较早检测出阳性鸡（P = 0.04）基本一致。在调查的7个养殖场中，商品鸡血清样本中抗禽流感HEV IgY抗体的总体流行率为44.8%（每个养殖场20-82%）。用巢式逆转录酶PCR检测粪便样本的禽流感HEV RNA。粪样中禽流感HEV RNA总检出率为62.9%（0 ~ 100%）。部分解旋酶和衣壳基因的测序分析表明，在一个农场内存在不同的禽HEV基因2型菌株。然而，禽HEV RNA检测与产蛋量、蛋重或死亡率之间没有相关性。总之，在美国临床健康的蛋鸡中，禽HEV感染很普遍。(C) 2015 Elsevier Ltd.版权所有。
The objective of this study was to determine patterns of avian HEV infection in naturally infected chicken farms. A total of 310 serum samples and 62 pooled fecal samples were collected from 62 chicken flocks on seven commercial in-line egg farms in the Midwestern United States and tested for avian HEV circulation. Serum samples were tested for the presence of anti-avian HEV IgY antibodies by a fluorescent microbead immunoassay (FMIA) which was developed for this study. The FMIA was validated using archived samples of chickens with known exposure (n = 96) and compared to the results obtained with an enzyme-linked immunosorbent assay (ELISA) based on the same capture antigen. There was an overall substantial agreement between the two assays (kappa = 0.63) with earlier detection of positive chickens by the FMIA (P = 0.04). On the seven farms investigated, the overall prevalence of anti-avian HEV IgY antibodies in serum samples from commercial chickens was 44.8% (20-82% per farm). Fecal samples were tested for avian HEV RNA by a nested reverse-transcriptase PCR. The overall detection rate of avian HEV RNA in fecal samples was 62.9% (0-100% per farm). Sequencing analyses of partial helicase and capsid genes showed that different avian HEV genotype 2 strains were circulating within a farm. However, no correlation was found between avian HEV RNA detection and egg production, egg weight or mortality. In conclusion, avian HEV infection is widespread among clinically healthy laying hens in the United States. (C) 2015 Elsevier Ltd. All rights reserved.