Gao Ya Huang Jintian Feng Xinru Fu Sheng Gao Wa Wang Wenlong Ding Yulin Wang Jinling
Two cases of feline infectious peritonitis (FIP) were detected and confirmed by necropsy, histopathology and immunohistochemistry, and the ORF of feline infectious peritonitis virus (FIPV) in the tissue samples of the two cases was amplified by RT-PCR. 7ab, N and S genes were sequenced and genetic evolution analysis was performed to clarify the genetic evolution characteristics of the virus. The results showed that both cases showed typical gross lesions of mixed FIP, with the abdominal cavity filled with serous fibrinous exudate. There are scattered or diffuse fine gray-white nodules on the serosal surface of the abdominal cavity. Histopathology shows inflammatory cell infiltration foci of varying sizes attached to the peritoneal surface, as well as necrotizing enteritis, interstitial pancreatitis and interstitial pneumonia. Immune tissue Chemical staining results showed that FPIV-specific strong positive signals were found in inflammatory cell infiltration foci, spleen and pancreas. Gene homology and genetic evolution analysis results showed that the genes of the two cases belonged to FCoV type I. IMAU No. 11685 and Zhejiang The Hangzhou ZJU1709 strain (MT239440) has the highest homology and the closest genetic relationship; IMAU No.11824 has the highest homology and the closest genetic relationship with the Hubei Wuhan QS strain (MW030108). This indicates that the two cases of FIPV and the domestic popular strains originated from the same Among them, the ORF 7ab and N genes are relatively conserved and the variation is not obvious, while the S gene undergoes certain mutations. The research results can provide reference for the molecular epidemiological research and prevention and control of FIP in my country.