Pathogenicity of a QX strain of infectious bronchitis virus in specific pathogen free and commercial broiler chickens, and evaluation of protection induced by a vaccination programme based on the Ma5 and 4/91 serotypes
Pathogenicity of a QX strain of infectious bronchitis virus in specific pathogen free and commercial broiler chickens, and evaluation of protection induced by a vaccination programme based on the Ma5 and 4/91 serotypes
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DOI：
10.1080/03079450802356938
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发表时间：
2008-10-01
期刊：
影响因子：
2.8
通讯作者：
Capua, Ilaria
中科院分区：
文献类型：
--
作者：
Terregino, Calogero;Toffan, Anna;Capua, Ilaria
本研究的目的是首先评估传染性支气管炎（IB）病毒意大利分离株QX株对1日龄雌性无特异性病原鸡的致病性（蛋鸡型）和1日龄雌性商品肉鸡型鸡，其次，评估通过包括IB马萨诸塞州和4/91血清型活减毒疫苗的疫苗接种程序在这些禽类中诱导的保护水平。未接种疫苗的禽类表现出不同严重程度的临床体征，主要影响上呼吸道。接种疫苗的鸡看起来很健康，除了影响有限数量的肉鸡的非常轻微的结膜炎。疫苗接种完全保护了无特定病原体的禽类，因为未观察到组织病理学病变，攻毒后也未检出病毒。在肉鸡中，攻击病毒的复制没有被阻止，但显着减少。本研究证实，使用Ma5和4/91 IB疫苗在1日龄和14日龄接种疫苗可能有助于降低蛋鸡和肉鸡养殖场中QX IB病毒感染的经济影响。
The aims of this study were firstly to evaluate the pathogenicity of an Italian isolate of the QX strain of infectious bronchitis (IB) virus using 1-day-old female specific pathogen free chicks (layer type) and 1-day-old female commercial broiler type chickens, and secondly to assess the level of protection induced in these birds by a vaccination programme including the IB Massachusetts and 4/91 serotype live attenuated vaccines. Unvaccinated birds showed clinical signs of varying severity, predominantly affecting the upper respiratory tract. Vaccinated birds appeared healthy, with the exception of a very mild conjunctivitis affecting a limited number of the broilers. Vaccination fully protected specific pathogen free birds, since no histopathological lesions were observed, nor was virus detected following challenge. In broilers, replication of the challenge virus was not prevented but was significantly reduced. This study confirms that vaccination at 1 day old and at 14 days of age using the Ma5 and 4/91 IB vaccines may be instrumental in reducing the economic impact of QX IB virus infections in layer and broiler farms.