Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, People's Republic of China.
Beijing Huadu Yukou Poultry Company Limited, Beijing 101206, People's Republic of China.
Poult Sci. 2019 Nov 1;98(11):5336-5341. doi: 10.3382/ps/pez351.
Proportions of QX-like genotype infectious bronchitis virus (IBV) isolates have increased over time. Here, to better understand the epidemiology and pathogenicity of IBV in China and control the spread of infectious bronchitis (IB), we conducted sequence analyses and examined the pathogenicity of 5 field isolates from diseased flocks in 2017 and 2018. Sequence analyses revealed that all the 5 strains, as well as many recent field isolates from other researchers, belonged to the QX-like IBV genotype, which were distantly related to commercial vaccine strains. Viral pathogenicity experiments showed that the isolates caused high morbidity and severe ciliostasis in chickens, although they caused milder lethality. This provides further evidence that QX-like IBV emergence remains a major problem in the poultry industry, and information on IBV epidemiology and pathogenicity may help to control IB.
QX 样基因型传染性支气管炎病毒（IBV）分离株的比例随着时间的推移而增加。在这里，为了更好地了解中国 IBV 的流行病学和致病性，并控制传染性支气管炎（IB）的传播，我们对 2017 年和 2018 年来自患病禽类的 5 个田间分离株进行了序列分析和致病性研究。序列分析表明，这 5 株病毒以及许多最近来自其他研究人员的田间分离株均属于 QX 样 IBV 基因型，与商业疫苗株亲缘关系较远。病毒致病性实验表明，这些分离株可引起鸡群高发病率和严重的纤毛停滞，尽管它们引起的死亡率较低。这进一步证明了 QX 样 IBV 的出现仍然是家禽业的一个主要问题，有关 IBV 流行病学和致病性的信息可能有助于控制 IB。
