猪圆环病毒和猪繁殖与呼吸综合征病毒混合感染对仔猪致病性的评估

本研究通过猪圆环病毒2型(Porcine circovirus type 2,PCV2)和猪繁殖与呼吸综合征(Porcine reproductive and respiratory syndrome virus,PRRSV)强毒共感染3周龄健康仔猪来评价其致病性。试验动物随机分为3组,空白对照组(n=3头),PRRSV单独感染组(n=3头),PCV2和PRRSV共感染组(n=6头),从而比较相互之间的差异。通过临床症状、病理学变化、病原学和血清学检查,对二者混合感染仔猪的致病性进行了研究。结果表明PCV2和PRRSV共同感染能引起仔猪断奶后多系统消耗性综合征,表现为淋巴组织肿大、出血,肉芽肿性炎症,坏死性肝炎,仔猪消瘦、生长缓慢等特征性病变;混合感染能加重PRRSV对仔猪引起的间质性肺炎的严重程度。混合感染可以出现支气管肺炎和明显的肝病变,淋巴结多呈界限明显的块状出血等典型病变。

Pathogenicity of porcine reproductive and respiratory syndrome virus and porcine circovirus type 2 coinfection in piglets

An attempt was made to evaluate the coinfection effects of porcine reproductive and respiratory syndrome virus (PRRSV)and porcine cireovirus type 2(PCV2)in the three-week-old post-weaning piglets.Three groups of piglets were mock- infected(n=3),PRRSV infected(n=3),and PCV2 and PRRSV co-infected(n=6),respectively and examined for clinical symptom,pathological changes,etiology and serology.The results indicated that PCV2 coinfection increased the severity of PRRSV-induced interstitial pneumonia in pigs and induced the lymphoid depletion,granulomatous inflammation,and necrotizing hepatitis characteristic of PMWS.The coinfection caused bronchopneumonia and hepatitis,and massive hemorrhage in lymphonodes.This clinical symptom is seldom seen in PRRSV infected group,but was a typical pathological change in the PRRSV and PCV2 coinfection group.