The Epidemic Of Feline Calicivirus Infection In Ordos And Homology Analysis Of VP1 Gene

Feline calicivirus belongs to caliciviridae,genus astrovirus,and is a single plus-strand RNA virus.It is one of the common causes of respiratory tract infection in felines,showing worldwide distribution,and can cause coughing,sneezing,increased eye secretions,oral ulcers,lamination,and other symptoms in felines.It not only causes great losses to cattery breeding but also brings more troubles to family cats.Cat calicivirus infection has been reported in both domestic and foreign literature.There is a lack of epidemiological investigation on FCVS in China,which is far different from foreign studies,so it is necessary to carry out relevant research work.This study investigated 237 suspected feline calicivirus infection cases from July2019 to December 2022.Among them,105 cases were infected with feline calicivirus and132 cases were not detected by hospital-based small fluorescent PCR,accounting for44.30% of the calicivirus infection rate.The symptoms of calicivirus infection were sneezing,runny nose,increased eye secretions,oral ulcers,fever,etc.The age distribution of infected cats ranged from one month to eight years old,and there was no significant difference between the sexes of infected cats.Of the 105 calicivirus cases,69 infected cats were simply infected with calicivirus,and 36 cats were infected with other respiratory pathogens besides calicivirus,feline herpes virus,mycoplasma,chlamydia,and haemophilus.The collected cat nose swabs were detected by RT-PCR in the laboratory,and the genetic evolutionary tree and homology analysis were conducted with the VP1 gene of the reference strain at home and abroad.The results showed that the similarities between the strains analyzed in this study and other isolates were 72.4% to 79.1%,and the similarities between FCV-eerduosi1 and KT000003.1 were the lowest(73.5%),and KM111557.1 had the highest similarity(79.1 %).FCV-eerduosi2 had the lowest similarity with DQ424892.1(72.4%).The similarity with KM111557.1 was 77.6%.The phylogenetic tree analysis showed that FCV-eerduosi1 and FCV-eerduosi2 are closely related to KJ495728.1,KF557763.1,KM111557.1 and KX815169.1 in the same clad.In this paper,the infection situation of calicivirus infection in cats in Ordos City and the homology analysis of infected strains were studied,so as to provide reference for the prevention and control of calicivirus vaccine and the epidemic and transmission of the disease,so as to reduce the widespread epidemic of the disease and reduce losses.