猫冠状病毒对猫的致病性研究

Pathogenicity of Feline Coronavirus in Cats

为了解猫冠状病毒(FCoV)在猫体内感染导致猫传染性腹膜炎(FIP)的临床特征和病变情况。本研究通过猫腹腔攻毒感染试验,验证两株来自患病猫腹水样品的FCoV阳性毒株能否导致猫出现FIP。结果表明,FCoV-GXNN531组攻毒14 d后,猫出现发热(>39.5℃),食欲逐渐废绝,体内出现严重的腹水(超过原来体重的25%),SAA值最高达到79.65 mg/L,而FCoV-HNZZ527组攻毒猫在感染32 d后出现发热(>39.5℃),厌食、消瘦、鼻眼分泌物增多、拉稀等临床症状,SAA最高到达105.81 mg/L。两株毒株均对实验猫多个脏器造成损伤,以肺脏、肾脏、肝脏较为严重,病理切片显示出不同程度的肺出血、肾小球肾炎、肝细胞变性坏死、脾窦狭窄、白髓萎缩等。RT-PCR检测结果表明两株病毒在肝脏、肺脏、脾脏、肾脏、膀胱、肠管、腹水均有复制。结果证明临床获得的两株毒株均能引起猫出现较为明显FIP症状,其中FCoV-GXNN531毒株可使猫出现严重腹水,临床表现为严重的腹膜炎。本研究为今后临床上及早诊断和预防FCoV的感染提供了一定的理论指导。

Feline coronavirus(FCoV)commonly causes intestinal infection in cats and occasionally causes systemic and lethal immunemediated diseases,which is known as feline infectious peritonitis(FIP).The purpose of the present study was to experimentally verify whether two FCoV strains from the ascetic fluid of sick cats could induce FIP in cats.The cats inoculated with the FCoV-GXNN531 strain showed fever(>39.5℃),gradual appetite abrogation and severe ascetic fluid(more than 25%of their original body weight),and SAA value up to 79.65 mg/L at 14 days post inoculation.The cats inoculated with the FCoV-GXNN531 strain showed fever(>39.5℃),anorexia,increased nasal and ocular discharges,diarrhea and SAA value up to 105.81 mg/L at 32 days post inoculation.Both strains induced visible lesions in many organs of infected cats,especially lungs,kidneys and livers.Pathological examination revealed pulmonary hemorrhage,glomerulonephritis,degeneration and necrosis in hepatocyte,stenosis of splenic sinus and atrophy of white pulp.The viral presence was demonstrated in livers,lungs,spleens,kidneys,bladders,intestines and ascetic fluids as detected by RT-PCR.These results indicated that both strains from clinical ascites caused obvious FIP disease in cats,especially the FCoV-GXNN531 strain produced severe ascites and peritonitis.This study provided useful reference for early diagnosis and prevention for FCoV infection in pet clinics.