Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, People's Republic of China.
Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, People's Republic of China.
Vet Microbiol. 2018 Jan;213:129-135. doi: 10.1016/j.vetmic.2017.11.027. Epub 2017 Nov 21.
Infectious bronchitis is a highly contagious, acute viral respiratory disease of chickens, caused by infectious bronchitis virus (IBV). In recent years, the isolation rate of QX-like IBV has increased in the world. To clarify this phenomenon and better understand the pathogenicity of QX-like IBV, we examined differences in pathogenicity between two IBV strains, SD and M41, which belong to QX-like and Mass-type IBV, respectively. SD strain was more virulent in 3-week-old specific-pathogen-free chickens than M41 strain causing higher mortality with severe renal lesions. The tissue distribution of the two virus strains was tested by real-time RT-PCR. The results showed that the viral genome copy numbers in the tissues of chickens inoculated with SD strain were higher than those in chickens inoculated with M41 strain, with the exception of the trachea and lung. This study indicates that there are tremendous differences in pathogenicity and tissue tropism between the QX-like strain and Mass-type strain. These findings may benefit the prevention of infectious bronchitis in the poultry industry in China.
传染性支气管炎是一种高度传染性、急性病毒性鸡呼吸道疾病，由传染性支气管炎病毒（IBV）引起。近年来，世界范围内分离到的 QX 样 IBV 的分离率有所增加。为了阐明这一现象，更好地了解 QX 样 IBV 的致病性，我们研究了属于 QX 样和 Mass 型 IBV 的两种 IBV 株，SD 和 M41，在致病性方面的差异。SD 株在 3 周龄 SPF 鸡中比 M41 株更具毒力，导致死亡率更高，并伴有严重的肾脏病变。通过实时 RT-PCR 检测了两种病毒株在组织中的分布。结果表明，接种 SD 株的鸡组织中的病毒基因组拷贝数高于接种 M41 株的鸡，除了气管和肺。本研究表明，QX 样株和 Mass 型株在致病性和组织嗜性方面存在巨大差异。这些发现可能有利于中国家禽业传染性支气管炎的预防。
