在无特定病原体的鸡胚模型中，对埃及高致病性禽流感病毒（H5N1和H5N8）分离株与弱毒和强毒新城疫病毒基因型VII之间的病毒干扰进行定量评估。

Quantitative evaluation of viral interference among Egyptian isolates of highly pathogenic avian influenza viruses (H5N1 and H5N8) with the lentogenic and velogenic Newcastle disease virus genotype VII in specific pathogen-free embryonated chicken eggs model.

作者信息

Soliman Mohamed A, Nour Ahmed A, Erfan Ahmed M

机构信息

National Laboratory for Veterinary Quality Control on Poultry Production, Animal Health Research Institute, Giza 12618, Egypt.

出版信息

Vet World. 2019 Nov;12(11):1833-1839. doi: 10.14202/vetworld.2019.1833-1839. Epub 2019 Nov 23.

DOI:10.14202/vetworld.2019.1833-1839

PMID:32009763

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC6925047/

Abstract

BACKGROUND AND AIM

Mixed infections of the highly pathogenic avian influenza virus (HPAIV) and Newcastle disease virus (NDV) are considered the most distressing problem of the poultry industry. The problem arises due to the influence of a hidden virus on the replication of another suspected virus. Consequently, misdiagnosis of the real cause of disease may become a source of infection for other healthy stock by transmission and dissemination of the hidden virus. This study aimed to determine the impact of HPAIV and NDV on each other in a specific pathogen-free embryonated chicken egg (SPF-ECE) model.

MATERIALS AND METHODS

HPAIVs (H5N1 and H5N8) and NDVs [avirulent NDV [avNDV] and velogenic NDV [vNDV]) were inoculated into the allantois cavity of SPF-ECE with graded titers (2, 3, and 4 log EID50) at 24 and 48 h of incubation, followed by the collection of allantoic fluid. A quantitative reverse transcription real-time polymerase chain reaction was used to determine the viral RNA copies of both viruses.

RESULTS

Obvious interference was reported on the growth of NDVs when co-inoculated with AIVs. NDV RNA titers reduction ranged from <3 to 5 log to complete suppression, but slight interference with the growth of AIVs occurred. H5N1 RNA titers showed <1-2 log reduction when co-inoculated with vNDV compared with the H5N1 control. The interference impact of H5N8 was more powerful than that of H5N1, while vNDV showed more resistance for interference than the avNDV strain. On the other hand, interference of AIVs was not observed except when vNDV was inoculated before H5N1. The interfering impact was increased after 48 h of inoculation, whereas no titer of avNDV was detectable.

CONCLUSION

AIV strains had a powerful effect on NDV growth, regardless of which infection occurred first.

摘要

背景与目的

高致病性禽流感病毒（HPAIV）和新城疫病毒（NDV）的混合感染被认为是家禽业最棘手的问题。该问题的出现是由于一种隐藏病毒对另一种疑似病毒复制的影响。因此，对疾病真正病因的误诊可能会通过隐藏病毒的传播成为其他健康家禽感染的源头。本研究旨在确定在无特定病原体的鸡胚（SPF-ECE）模型中HPAIV和NDV对彼此的影响。

材料与方法

将HPAIVs（H5N1和H5N8）和NDVs [无毒力NDV（avNDV）和强毒力NDV（vNDV）] 以分级滴度（2、3和4 log EID50）在孵化24小时和48小时时接种到SPF-ECE的尿囊腔中，随后收集尿囊液。采用定量逆转录实时聚合酶链反应来测定两种病毒的病毒RNA拷贝数。

结果

当与禽流感病毒共同接种时，报告了对新城疫病毒生长的明显干扰。新城疫病毒RNA滴度降低范围从<3至5 log到完全抑制，但对禽流感病毒的生长有轻微干扰。与H5N1对照相比，H5N1与vNDV共同接种时RNA滴度显示降低<1-2 log。H5N8的干扰作用比H5N1更强，而vNDV对干扰的抵抗力比无毒力NDV株更强。另一方面，除了在H5N1之前接种vNDV外，未观察到禽流感病毒的干扰。接种48小时后干扰作用增强，而未检测到无毒力NDV的滴度。