Epidemiological Investigate Of Feline Immunodeficiency Virus And Analysis Of The Representative Genomic

Feline immunodeficiency virus(FIV)belongs to Retrovirus family,Lentivirus genus that causes immunosuppression,with depletion of TCD4+ lymphocytes,with the majority of clinical signs caused by secondary and opportunistic infections.Feline with FIV is often associated with some diseases,such as oral diseases,skin diseases,diarrhea,pneumonia,eye diseases,and even central nervous system diseases,eventually death.FIV is distributed worldwide,with infection rates varying between 2.5%and 44%.FIV is mainly transmitted through the blood,secondly,saliva and urine were also reported.In addition to infecting domestic pets and stray cats,FIV also infects a large number of wild feline.In recent years,there have been reports of wild felines infected with FIV such as lions,tigers,and leopards in foreign wildlife parks.In China,the current status of FIV infection among stray cats and other wild felines is almost blank.Therefore,the rapid diagnosis and epidemiological investigations of this disease are necessary carried out,and it is benefits for taking some preventive and management measures,and for reducing the harm and impact of this disease on felines.In this study,All samples were tested by ELISA(SNAPR Combo FeLV Ag/FIV Antibody Test)and nested polymerase chain reaction(nested-PCR)assay.All 274 stray cat blood samples were collected from Harbin and Shanghai.17 FIV positive and 2 FeLV(Feline leukemia virus)positve were detected by ELISA;11 cats were FIV positive by nested-PCR.PCR detection of FeLV was negative.The positive detection rate was 4%(11/274).Among the 11 positive FIV cats,5 cats from Shanghai,6 cats from Harbin;8 male cats and 3 female cats.Gag gene was amplified by nested PCR to detect FIV.Phylogenetic analysis of env V3-V5 showed that eleven samples clustered within subtype A.One of the complete genomic DNA sequences was cloned and the major open reading frames(ORFs)gag,pol,env,vif,wihich is about 1350 bp,3096 bp,2565 bp,and 756 bp encoding 449,1031,854 and 251 amino acids.Full gene sequence was submitted to GenBank MF352016.Compared with PPR(M3 6968)and Petaluma(NC001482),the homology of gag gene was 96.64%and 95.55%;the env gene was 87.70%and 93.70%;the pol gene was 83.76%and 95.59%;the vif gene was 91.0%and 93.43%.Compared with FIVCG(M25381)and Petaluma(NC001482)which are all subtype A,the homology of full-length of FIV was 93.11%and 93.16%,respectively,and 81.22%homology with BM3070(AF474246)belonging to FIV subtype C,52.01%with FIV of Pantheraleo 1027(EU117992)?In summary,11 positive FIVs were detected in this experiment,and the total detection rate was 4%.The phylogenetic tree was constructed to determine it as subtype A.The evolutionary analysis of the major ORFs of FVI indicated that gag and pol genes were relatively conserved during long-term genetic variation,and env showed a great diversity.