实验性鸡大肠杆菌病的超微动态病理变化

10～ 12日龄 SPF鸡 180只 ,随机分为 4组 ,分别气管内注射致病性大肠杆菌 O18分离株 (大肠杆菌接种组 )、低致病性禽流感病毒 (mildly pathogenic avian influenza virus,MPAIV) H9N2株 (MPAIV接种组 )、先接种 MPAIV再接种大肠杆菌 (混合接种组 ) ,并设健康对照组 ,分别于接种后不同时间 ,取气管、肺、气囊、胸腺、法氏囊、脾、肝和肾组织 ,制作超薄切片 ,电镜观察。结果表明 ,MPAIV与大肠杆菌混合接种组比大肠杆菌接种组出现病变的时间早、恢复慢 ;在大肠杆菌接种组 ,接种后 3h气囊上皮和间质细胞中都可见典型的大肠杆菌 ;在混合接种组 ,接种后 3h,气囊间质细胞的吞噬泡中可见多个 MPAIV粒子。由此认为 ,MPAIV可使鸡大肠杆菌病严重化 ,大肠杆菌对 MPAIV的入侵和在鸡体内的复制可能有促进作用。

Ultrastructurally Pathologic Dynamics of Colibacollosis in Chickens Experi mentally Inoculated with E.coli and/or Mildly Pathogenic Avian Influenza Virus

Ten or 12-day-old SPF chickens were inoculated intracheally with virulent E.coli(O18) and/or mildly pathogenic avian influenza virus(MPAIV).Chickens inoculated with E.coli and MPAIV had more severe and persistent ultrastructurally pathologic lesions than those inoculated with E.coli alone,or with MPAIV alone.Bacteria were adherent to and present within the epithelial cells at 3 h postinoculation and were also seen in the connective tissue of the air sacs in the chickens inoculated with E.coli alone.At the same time,MPAIV were seen in the connective tissue of the air sacs in the chickens inoculated with MPAIV and E.coli.These results suggest that MPAIV might facilitate E.coli invasion into the respiratory tract of the chicken resulting in more severe avian colibacillosis,and E.coli might facilitate the invasion and/or reproduction of MPAIV.