Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, P. R. China.
Avian Pathol. 1998;27(6):578-85. doi: 10.1080/03079459808419387.
Eight strains of infectious bronchitis virus (IBV) were isolated between 1986 and 1995 from broilers and layers at eight different farms in four provinces in China. The viruses were isolated from flocks which suffered from either respiratory disease or nephritis and the majority had not been vaccinated against IBV. Six strains were shown by monoclonal antibodies to differ from H120, Connecticut and Arkansas 99 strains of IBV and also to differ from each other. Four of these strains were serotyped; one (NRZ) was of the Massachusetts serotype, three (HV, NB-90 and TJ) shared a degree of antigenic similarity and were of a serotype that differed from Massachusetts and Connecticut. NB-90 was similar to both Gray and T strains whereas TJ shared some similarity with the T strain. Four strains, HV, NB-90, YY and TJ induced 33, 47, 60 and 90% mortality, respectively, in 3-week-old specific pathogen-free chickens. Clinical signs and post-mortem findings were identical to those induced by the nephropathogenic T strain. Chickens vaccinated with H120 strain, and then challenged with four highly pathogenic strains HV, NB-90, YY and TJ were not protected as determined by both virus isolation and mortality. The results show that highly pathogenic IBV strains which induce clinical nephritis occur frequently in poultry flocks in China. They also confirm field observations on the lack of protection by currently used IB vaccines of the Massachusetts serotype against challenge with these nephropathogenic strains.
1986 年至 1995 年期间，从中国四个省份的八个不同农场的肉鸡和蛋鸡中分离到了 8 株传染性支气管炎病毒（IBV）。这些病毒是从患有呼吸道疾病或肾炎的鸡群中分离出来的，大多数鸡群没有接种过 IBV 疫苗。用单克隆抗体检测发现，其中 6 株病毒与 H120、康涅狄格和阿肯色 99 株 IBV 不同，彼此之间也存在差异。这 4 个分离株被血清型鉴定；其中一个（NRZ）为马萨诸塞血清型，3 个（HV、NB-90 和 TJ）具有一定程度的抗原相似性，属于与马萨诸塞和康涅狄格血清型不同的血清型。NB-90 与 Gray 和 T 株相似，而 TJ 与 T 株有一些相似之处。HV、NB-90、YY 和 TJ 株分别在 3 周龄 SPF 鸡中引起 33%、47%、60%和 90%的死亡率。临床症状和剖检变化与致肾炎的 T 株引起的相同。用 H120 株免疫接种后，再用 4 株高致病性株 HV、NB-90、YY 和 TJ 进行攻毒，结果发现鸡没有得到保护，无论是通过病毒分离还是死亡率来判断都是如此。结果表明，引起临床肾炎的高致病性 IBV 株在中国家禽中经常发生。这些结果还证实了田间观察结果，即目前使用的马萨诸塞血清型 IB 疫苗不能预防这些致肾炎的高致病性株的攻毒。
