Establishment Of Methods For FHV-1 GI Sequence Analysis And PCR Diagnoses

The feline viral rhinotracheitis(FVR)is also known as feline contagious rhinotracheitis.This is a highly contagious viral disease caused by Feline herpesvirus type 1(FHV-1)in the feline,it is characterised by upper respiratory track sign,mainly affects on kittens,with a morbidity of 100%,and mortality of 50%.Also,adult cats can catch up this disease but with a relatively lower mortality.Animals recovered from infections may then become persistent carriers,they would be shedding the virus intermittently throw their life time.It is very difficult to differentiate this disease from other feline upper respiratory disease.There is no current snap test for this disease,all definitive diagnoses are based on laboratory test,but they all have the disadvantages with long time,and low sensitivity,so they are not clinically plausible.Therefore,PCR test is the most effective test above all of them.This study is targeting to establish a PCR test with high specificity and sensitivity.The specific primers used in this study is according to the GenBank published the gI gene sequence,and Amplify the suspected sample's gene with FHV-1 gI gene sequence template and make the standard positive plasmid.It has also optimised the established PCR diagnostic method,at the same time to optimise the PCR diagnostic method for sensitivity,specificity,and repeatability,polymerase chain reaction(PCR)to depend on this experiment established FHV-1 for 46 clinical samples for testing.Results showed that the sequence from the suspected disease is expected to enlarge the gI FHV-1 gene and its clones positive plasmid preparation standards,results of a grain of sequencing analysis showed that the cloned gl gene has 1155 bp,and the homogenous similarity to other FHV-1 strain is above 99.7%,the evolutionary tree analysis results show that with the Australia strains(KR381787.1)'s closest relative.With optimisation of PCR method to determine the best annealing temperature is 56?,the lowest detection DNA template concentration of 3.23 x 103 copies/?L(that is,the minimum detectable 136.5 fg/target DNA(including L)in terms of specific testing this method specific detection FHV-1 can't check out the canine parvovirus(CPV),canine distemper virus(CDV)and Mycoplasma Ovipenumoniae(Movi),Mycoplasma Bovis(M.b ovis),bovine herpesvirus type I(BHV-1).The method of this study used for 46 sample's test,which turned out that 28 samples are positive,positive rate was 60.87%,positive sample's from PCR test products with GenBank recorded FHV-1 on behalf of the homologous strains has a 99%similarity.Showing that the established PCR diagnostic method has strong specificity,high sensitivity,the characteristics of fast and exact detection of clinical specimens can be adopted.