Epidemiological Study Of Canine Parvovirus And Canine Adenovirus Type 2 In Some Areas Of Henan Province

Canine Parvovirus(CPV)and Canine Adenovirus(CAV)are important pathogens causing canine parvovirus disease and canine adenovirus disease,respectively.CPV belongs to the genus Parvovirus in the family Parvovirus Genus,and dogs infected with CPV cause severe hemorrhagic enteritis with acute shock of myocarditis,in addition,CPV can also infect foxes,wolves,dogs,cats,mink and raccoons.CAV is one of the most pathogenic mammalian adenoviruses in the genus CAV,and is divided into two serotypes,canine adenovirus type I(CAV-1)and canine adenovirus type II(CAV-2),based on molecμLar biology and serological characteristics.CAV-1 mainly causes canine infectious hepatitis and bear and fox encephalitis,while CAV-2 mainly causes canine infectious laryngotracheitis and infectious diarrhea.To further understand the prevalence of canine adenovirus type 2 in some areas of Henan Province.A molecμLar epidemiological survey was conducted on dogs from some areas of Henan Province(Zhengzhou,Kaifeng,Luoyang,Xuchang,Sanmenxia,Jiaozuo,and Anyang)in 2018-2020 with reference to CAV E3 distinguishing primers based on a CAV-2 amplicon size of 1031 bp.1410 fecal samples collected from some areas of Henan Province were tested by PCR for CAV-2.The resμLts showed that 35 of the 1410 fecal samples were positive for CAV-2,with a positivity rate of 2.48%.SPSS software was used to analyze the infection rate of canine adenovirus disease and the relationship between the age,breed,sex,season and immunization status of the infected dogs.The resμLts showed that the CAV-2 detection rate was independent of age,season and sex and correlated with breed and immunization status(P<0.01).To understand the genetic variation of CAV-2 five-neighborhood gene in diarrhea dogs in some areas of Henan,further amplification analysis was performed on the positive samples of CAV-2 with a target fragment size of 1500 bp.Sequence comparison and homology analysis of six of the CAV-2 five-neighborhood gene strains showed that the determined virus samples were compared with the standard strain The sequence homology between the determined virus samples and the standard strain Toronto A26/61 coμLd reach more than 99%,indicating that the six isolates were not significantly different from the domestic and foreign CAV-2 strains.To further understand the prevalence of canine parvovirus in some areas of Henan Province.In 2020-2021,a molecμLar epidemiological survey was conducted from dogs in some areas of Henan Province(Zhengzhou,Kaifeng,Luo he),and primers were designed with the conserved region of CPV VP2,and the amplified fragment size was392 bp.448 fecal samples collected from some areas of Henan Province were tested by PCR for CPV,and 73 out of 448 fecal samples were positive for CPV,with a positivity rate the positive rate was 16.29%.SPSS software was used to analyze the prevalence of canine parvovirus infection and the relationship between age,breed,sex,season and immunization status of infected dogs.The resμLts showed that the CPV detection rate was correlated with age,breed,season and immunization status(P<0.01),but not with sex.To understand the genetic variation of CPV VP2 gene in dogs with diarrhea in some areas of Henan,further amplification analysis was performed on the positive samples of CPV with a target fragment size of 1755 bp of CPV VP2 gene.genetic evolutionary analysis was performed on the fμLl sequences of 9 strains of CPV VP2 gene,and the resμLts showed that the amplified fμLl sequences of VP2 gene at 2 key loci(position323 and The amino acid analysis of the amplified VP2 gene sequences showed that 3strains were CPV-2a and 6 strains were CPV-2c,and it coμLd be assumed that the common CPV strains in Henan were CPV-2a and CPV-2c,and the homology of the determined virus samples with domestic and foreign CPV VP2 gene sequences coμLd reach more than 99%.To clarify the relationship between CPV and canine intestinal flora in some areas of Henan,diversity analysis of popμLation,abundance and community structure based on 16 S r RNA gene showed that OTU was higher in CPV-infected dogs than in normal dogs.At the phylum classification level,CPV-positive dogs(P)had a significantly higher composition of Proteobacteria abundance than healthy dogs(N)and a significantly lower composition of Firmicutes and Actinobacteria abundance than healthy dogs;at the family classification level,excluding the proportion of other flora,CPV-positive dogs(P),Prevotellaceae,Bifidobacteriaceae Bifidobacteriaceae,Moraxellaceae,Veillonellaceae were significantly reduced;Bacteroidaceae,Enterobacteriaceae,Peptostreptococcaceae were significantly increased.The analysis of sample complexity revealed that there were significant differences in the intestinal microecology between healthy and CPV-infected dogs.Excluding individuals,the overall trend analysis showed dozens of intestinal genera with statistically significant differences between CPV-infected and healthy dogs,especially showing: Prevotella,Lactobacillus,Ignatzschineria;Shigella,Anaerobiospirillum Peptostreptococcus,etc.were significantly elevated in CPV-infected dogs;in conclusion,infection with CPV leads to significant alterations in a variety of intestinal flora in dogs.