2株胶东地区Ⅰ群禽腺病毒分离株的致病性试验

Study on the Pathogenicity of Two Fowl Adenovirus Isolates from Jiaodong Area

将从胶东地区疑似Ⅰ群禽腺病毒(FAdV)感染的发病鸡的肝组织病料中分离鉴定出的FAdV-8b(FXWH-8b)株和FAdV-4(FXWH-4)株,通过腿部肌肉注射方式,以TCID 50108.00.2 mL/羽的剂量,接种15日龄的SPF鸡,临床观察其发病情况及临床表现,研究其毒力和致病性。临床观察和剖检结果显示:FXWH-8b株和FXWH-4株均能在24 h引起试验鸡只发病,表现明显的临床症状和典型的剖检病理变化。H.E.染色结果显示:2株分离株均在脑、胸腺、气管、心脏、肝脏、脾脏、肺脏、肾脏、腺胃、胰腺、十二指肠、空肠、盲肠和法氏囊有较明显的病理变化,但均未发现核内包涵体。PCR检测结果显示:FXWH-8b株攻毒后72 h,FXWH-4株攻毒后48 h,在肝脏、肺脏、肾脏、腺胃、空肠和盲肠呈现100%的阳性率。免疫组化结果显示:FXWH-8b株和FXWH-4株均在肝脏存在强阳性信号;FXWH-4株在肾脏、十二指肠和空肠存在阳性信号。表明FXWH-8b株和FXWH-4株均对15日龄SPF鸡有较强的致病性,可侵害多个组织和器官。

FAdV-8b strain and FAdV-4 strain which were named as FXWH-8b strain and FXWH-4 strain respectively,were separated and identified from Shandong area.We administered the viruses to 15-day-old SPF birds by muscular injection in the leg,and observed the clinical signs.Results showed that both FXWH-8b and FXWH-4 infection caused diseases in the birds,with obvious clinical signs and pathologic changes.Both strains caused significant pathologic problem in brain,trachea,heart,liver,spleen,lung,kidney,proventriculus,pancreas,duodenum,jejunum,ceca and bursa by H.E.staining.However,we did not find intranuclear inclusion body.Both strains replicated very fast in various organs after challenge,and we found 100%virus recovery from liver,lung,kidney,proventriculus,jejunum and ceca 72 hours post challenge for FXWH-8b,and 48 hours for FXWH-4.Immunohistochemistry showed that FXWH-8b strain and FXWH-4 strain replicated mainly in liver,while FXWH-4 is also replicated in liver,kidney,duodenum and jejunum.These data indicate that both FXWH-8b and FXWH-4 have higher pathogenicity to 15-day-old SPF chickens,and could damage many tissues and organs.