Efficacy and safety of an attenuated live QX-like infectious bronchitis virus strain as a vaccine for chickens
Efficacy and safety of an attenuated live QX-like infectious bronchitis virus strain as a vaccine for chickens
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DOI：
10.1080/03079457.2010.542742
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发表时间：
2011-01-01
期刊：
影响因子：
2.8
通讯作者：
Kumar, M.
中科院分区：
文献类型：
--
作者：
Geerligs, H. J.;Boelm, G. -J.;Kumar, M.
描述了传染性支气管炎（IB） qx样病毒株L1148的衰减。该病毒在无特异性病原体（SPF）鸡胚中传代多次，并在不同传代水平下对1日龄SPF鸡呼吸道和肾脏的安全性进行了测试。当病毒经过大量的传播后，对呼吸道和肾脏的致病性明显降低。研究了1日龄和7日龄SPF鸡生殖道传代水平80的安全性。在1日龄的鸡中，12.5%的接种鸡有肉眼可见的病变。如果鸡在7日龄时接种疫苗，则未观察到病变。传代水平为80，研究了其从接种疫苗的鸡向未接种疫苗的鸡传播的能力以及在体内的传播能力。该病毒能够从接种疫苗的鸡群传播到未接种疫苗的鸡群，并且在接种疫苗的鸡中，经常在口咽和肛肠拭子中发现该病毒。对传代水平为80的S1蛋白的高变区片段进行测序，发现核苷酸变化导致两个氨基酸取代。80级通道在82级和85级的基础上增加了额外的通道。两个传代水平分别在SPF鸡和85传代水平用母源性抗体（MDA）检测商品鸡对qx样菌株IB D388攻击的有效性。在SPF鸡和MDA鸡中，以菌株IB L1148为基础的疫苗对攻毒均有效。
The attenuation of infectious bronchitis (IB) QX-like virus strain L1148 is described. The virus was passaged multiple times in embryonated specific pathogen free (SPF) chicken eggs, and at different passage levels samples were tested for safety for the respiratory tract and kidneys in 1-day-old SPF chickens. There was a clear decrease in pathogenicity for the respiratory tract and kidneys when the virus had undergone a large number of passages. Passage level 80 was investigated for safety for the reproductive tract in 1-day-old and 7-day-old SPF chickens. In 1-day-old chickens, 12.5% of the vaccinated birds had macroscopic lesions. No lesions were observed if the chickens had been vaccinated at 7 days of age. Passage level 80 was investigated for its ability to spread from vaccinated to non-vaccinated chickens and for dissemination in the body. The virus was able to spread from vaccinated chickens to groups of non-vaccinated chickens, and in the vaccinated birds the virus was found frequently in oro-pharyngeal and cloacal swabs. A fragment of the hypervariable region of the S1 protein of passage level 80 was sequenced and revealed nucleotide changes resulting in two amino acid substitutions. Passage level 80 was given additional passages to levels 82 and 85. Both passage levels were tested for efficacy in SPF chickens and passage level 85 was tested for efficacy in commercial chickens with maternally derived antibodies (MDA) against a challenge with QX-like strain IB D388. In both SPF chickens and chickens with MDA, the vaccines based on strain IB L1148 were efficacious against challenge.