鸡传染性支气管炎病毒合肥分离株S1基因序列及致病性分析

Analysis of S1 Gene Sequence and Pathogenicity of an Avian Infectious Bronchitis Virus Isolate from Hefei,China

从安徽合肥一养殖户送检的临床样品中分离到一株鸡传染性支气管炎病毒,命名为HF200702。分离株在鸡胚盲传3代过程中可引起典型的侏儒胚现象;基于分离株S1基因序列对毒株进行分型结果显示,分离株属于目前流行的QX型,与H120、M41、4/91、QX等疫苗株的同源性分别为76.1%、75.6%、78.3%、95.0%;用分离株第10代鸡胚尿囊液感染1日龄SPF雏鸡,对雏鸡的致死率为41.6%,感染鸡出现精神沉郁、张口呼吸、气管啰音等临床症状以及气管纤毛摆动停滞、肾脏肿大、尿酸盐沉积等病理变化。感染鸡从感染后第2 d开始持续向外界排毒直至感染后28 d。该研究数据表明,从安徽合肥某养鸡场疑似发生传染性支气管炎的鸡群中分离到QX型的IBV,该毒株对雏鸡有较强的致病作用,研究结果为了解该地区IBV的流行情况提供了参考数据。

An Avian infectious bronchitis virus (IBV) strain HF202007 was isolated from clinical samples collected from a farm in Hefei,Anhui province.This isolate caused typical dwarf embryos during 3 blind passages.The genotyping of S1 gene of this isolate showed that it belonged to QX-like type,which was a dominant genotype in China.The allantoic fluid of chick embryos infected the 10th passage virus was used to infect one day old SPF chickens.The mortality of infected chickens was 41.6%.All the infected chickens showed respiratory signs such as coughing,sneezing and tracheal vocalization.The kidneys of dead birds were swollen,pale and exhibited severe urate deposition.The virus-shedding from infected chickens started 2 dpi until 28 dpi.In summary,QX-like IBV strain HF202007 was isolated from Hefei,Anhui province and pathogenic to young chickens.This study provided a reference for understanding the epidemic situation of IBV in this area.