致雏鹅痛风新型鹅星状病毒的分离鉴定和致病性试验

Isolation,Identification and Pathogenicity Test of a Novel Goose Astrovirus Causing Gout in Gosings

为了解黑龙江省齐齐哈尔市某鹅场雏鹅发病原因,本试验对鹅场疑似感染鹅星状病毒(GoAstV)的雏鹅进行剖检,采集具有典型痛风症状病死鹅的肝脏、脾脏和肾脏,进行病原分离、PCR扩增、基因序列分析和动物回归试验。结果显示,将分离得到的病原接种鹅胚后,72~168 h死亡率约为90%;剖检死亡鹅胚可见尿囊膜水肿并有尿酸盐沉积、胚体严重充血水肿呈潮红色。基因序列比对结果显示,分离毒株与近年来报道的引起禽类痛风的新型GoAstV毒株HNSQ-6、HNKF-1、HNNY0620和XT1的核苷酸同源性较高,达99.58%~99.72%。动物回归试验结果显示,攻毒后雏鹅的临床症状与自然感染雏鹅的发病症状一致;攻毒后雏鹅死亡率约70%,未死亡鹅的生长受到严重抑制;剖检死亡雏鹅可见心脏、肝脏和肾脏表面出现明显的尿酸盐沉着,部分死亡雏鹅关节腔内有尿酸盐沉积。结果表明,从黑龙江省齐齐哈尔市某鹅场病死雏鹅中分离的致病原为GoAstV。

To investigate the cause of gosling diseases at a goose farm in Qiqihar City,Heilongjiang Province,this study conducted post-mortem examinations on suspected goslings infected with goose astrovirus(GoAstV).Liver,spleen,and kidney samples were collected from goslings that exhibited typical gout symptoms and had died of the disease.The collected samples underwent pathogen isolation,PCR amplification,gene sequence analysis,and animal regression test.The results showed that when the isolated pathogen was inoculated into goose embryos,the mortality rate reached about 90%within 72 to 168 hours.Post-mortem examinations of the deceased goose embryos revealed urinary bladder edema with urate deposition,and severe congestion with edema,appearing red and swollen.Gene sequence alignment results indicated a high nucleotide homology(99.58%to 99.72%)between the isolated strain and recently reported novel GoAstV strains causing avian gout,such as HNSQ-6,HNKF-1,HNNY0620,and XT1.Animal regression test results showed that the clinical symptoms of goslings after inoculation were consistent with those of naturally infected goslings.The mortality rate of goslings after challenge was approximately 70%,and the growth of surviving goslings was severely inhibited.Post-mortem examinations of deceased goslings revealed noticeable urate deposition on the surfaces of the heart,liver,and kidneys,with some showing urate deposits in the joint cavities.These results indicate that the pathogen isolated from the diseased goslings at the goose farm in Qiqihar City,Heilongjiang Province,is GoAstV.