State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China.
State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China.
Vaccine. 2018 Jul 5;36(29):4245-4254. doi: 10.1016/j.vaccine.2018.05.123. Epub 2018 Jun 8.
Infectious bronchitis (IB) is an acute, highly contagious disease, which causes economic losses to the poultry industry worldwide. To control the disease, biosecurity and vaccination are required. In the current research, we rapidly attenuated a QX-like IBV field strain ZYY-2014 using passage in embryos at limiting dilution and tested the safety and efficacy of the attenuated Chinese QX-like IBV strain ZYYR-2014 in 1-day-old specific-pathogen-free (SPF) chickens through spray route. Our result revealed that the attenuated strain presented a decreased pathogenicity in 1-day-old chickens. The strain ZYY-2014 inoculated birds presented typical IBV clinical signs with a mortality of 43%, while the attenuated strain ZYYR-2014 inoculated birds remained healthy. The strain ZYYR-2014 also presented stronger antibody responses and lower viral loads in tracheas, lungs and kidneys. When vaccinated through spray route into 1-day-old SPF chickens, our data suggest a potential of the attenuated ZYYR-2014 strain as a vaccine candidate applied in hatchery, which can contribute in preventing the QX-like IBV infections. Furthermore, attenuation by passage at limiting dilution could be applied for rapid vaccine development against emerging strains.
传染性支气管炎（IB）是一种急性、高度传染性疾病，给全球家禽业造成了经济损失。为了控制这种疾病，需要采取生物安全措施和接种疫苗。在目前的研究中，我们通过在胚胎中进行有限稀释传代快速减弱了一株类似于 QX 的 IBV 野毒株 ZYY-2014，并通过喷雾途径在 1 日龄 SPF 鸡中测试了该减弱的类似于 QX 的中国 IBV 株 ZYYR-2014 的安全性和效力。我们的结果表明，减弱的菌株在 1 日龄鸡中表现出降低的致病性。接种 ZYY-2014 株的鸟类表现出典型的 IBV 临床症状，死亡率为 43%，而接种减弱株 ZYYR-2014 的鸟类保持健康。ZYYR-2014 株还在气管、肺和肾脏中引起更强的抗体反应和更低的病毒载量。当通过喷雾途径接种到 1 日龄 SPF 鸡中时，我们的数据表明，减弱的 ZYYR-2014 株作为一种疫苗候选株在孵化场中具有应用潜力，可以预防类似于 QX 的 IBV 感染。此外，通过有限稀释传代进行的减弱可以应用于新兴菌株的快速疫苗开发。
