ABSTRACT
Porcine reproductive and respiratory syndrome virus (PRRSV) has proven to be highly genetically variable; however, comprehensive information regarding the virus's genetic diversity in South China is limited. In this study, a total of 3199 clinical samples were collected from 267 pig farms suspected of PRRSV infection between 2007 and 2011. The ORF5 genes of 51 PRRSV-positive samples were sequenced and analyzed. The 51 study strains were divided into three primary subgenotypes. Fourty-five of the strains belonged to subgenotype I and were closely related to the highly pathogenic PRRSV (HP-PRRSV) strains. The subgenotype I strains were generally clustered into genetically similar groups by year. Only one of the strains belonged to subgenotype II, clustering with the classical North American type, VR2332. Five of the strains were grouped into subgenotype III, which occupied a separate branch and was closely related to the recently isolated novel field strains, QYYZ and GM2. The 5 subgenotype III strains shared an amino acid identity with the remaining 46 study strains ranging from 79.6%-83.6%. Amino acid analysis showed extensive mutations in subgenotype III; the diverse genetic mutations of these novel strains are of great concern.
Subject(s)
Porcine Reproductive and Respiratory Syndrome/epidemiology , Porcine Reproductive and Respiratory Syndrome/virology , Porcine respiratory and reproductive syndrome virus/classification , Porcine respiratory and reproductive syndrome virus/isolation & purification , Viral Envelope Proteins/genetics , Animals , China/epidemiology , Cluster Analysis , Genotype , Molecular Epidemiology , Molecular Sequence Data , Porcine respiratory and reproductive syndrome virus/genetics , RNA, Viral/genetics , Sequence Analysis, DNA , Sequence Homology, Amino Acid , SwineABSTRACT
Porcine circovirus type 2 (PCV2), the primary causative agent of porcine circovirus-associated diseases (PCVADs), is a serious economic problem for the swine industry worldwide. Three major PCV2 genotypes (PCV2a, PCV2b, and PCV2c), have been identified. To explore the prevalence of different subgroups of PCV2 in southern China, 66 PCV2 isolates collected during 2011-2012 were analyzed. PCV2b was the predominant genotype circulating in southern China from 2011 to 2012. Moreover, subtype 1C was the predominant subtype. Comparisons of the complete ORF2 nucleotide sequence revealed 89.3-100% homology and 87.2-100% amino acid sequence identities. The deletion at position 1042 and two nucleotide substitutions at positions T1035A or T1033C were important for the PCV2 evolution. Base-by-base of ORF2 comparison showed that the PCV2 evolution trace was PCV2a to PCV2b-1A1B to PCV2b-1C. These results contribute to the understanding of PCV2 epidemiology in southern China.
Subject(s)
Circoviridae Infections/veterinary , Circovirus/classification , Circovirus/genetics , Evolution, Molecular , Genotype , Phylogeny , Swine Diseases/epidemiology , Animals , Base Sequence , China/epidemiology , Genome, Viral , Molecular Sequence Data , Prevalence , Sequence Alignment , SwineABSTRACT
Reports of dogs with H3N2 canine influenza virus (CIV) have been documented frequently. To better understand the seroprevalence of H3N2 CIV among dogs in northeast China, here we report for the first time a relatively high seroprevalence of H3N2 CIV infection in dogs in northeast China. Forty-five of the 223 canine sera (20.2%) and 166 of the 500 canine sera (33.2%) tested feral dogs and pet dogs were seropositive by NP-ELISA, which is higher than that in southern China. The relative data provided in this report can be useful for small animal practitioners or public health policy makers to carry out relative measures for the prevention of this disease. Meanwhile, similar seroprevalence studies and prospective natural history and incidence studies should also be undertaken in other places.
Subject(s)
Dog Diseases/epidemiology , Dog Diseases/immunology , Dog Diseases/virology , Influenza A Virus, H3N2 Subtype/immunology , Orthomyxoviridae Infections/veterinary , Animals , Antibodies, Viral/blood , China , Dogs , Enzyme-Linked Immunosorbent Assay/veterinary , Orthomyxoviridae Infections/epidemiology , Orthomyxoviridae Infections/immunology , Seroepidemiologic StudiesABSTRACT
Porcine reproductive and respiratory syndrome (PRRS) is considered one of the most important infectious diseases to affect the swine industry and characterized by reproductive failure in late term gestation in sows and respiratory disease in pigs of all ages. The GP5a gene, encoding RNA-dependent RNA polymerase, is generally regarded as fairly conserved when compared to other viral proteins. It plays an important role in the process of duplication and transcription carried out by Porcine reproductive and respiratory syndrome virus (PRRSV). We firstly expressed and purified the GP5a protein of PRRSV. This provides a good method for the purification of expressed proteins and the preparation of the corresponding antibodies.
ABSTRACT
The primary objective of this 3 years study was to determine the prevalence of porcine pathogens of the lungs of swine in swine farms in southern China. A total of 5,420 samples were collected from 200 swine farms. The bacterium that was most commonly isolated was Streptococcus suis, with 10.24 % of the samples being positive, 114 lungs (2.1 %) were positive for pseudorabies virus and 263 (4.85 %) were positive for classical swine fever virus; much lower than positive for PRRSV (15.1 %, p = 0.023) and PCV2 (13.8 %, p = 0.038). lungs that were positive for PRRSV and/or PCV-2 have significantly increased odds of being positive for any of the S. suis (9.79 vs. 0.44 %, p = 0.003).
ABSTRACT
We report here the complete genomic sequence of the duck Tembusu virus (DTMUV) WJ-1 strain, isolated from Muscovy ducks. This is the first complete genome sequence of DTMUV reported in southern China. Compared with the other strains (TA, GH-2, YY5, and ZJ-407) that were previously found in eastern China, WJ-1 bears a few differences in the nucleotide and amino acid sequences. We found that there are 47 mutations of amino acids encoded by the whole open reading frame (ORF) among these five strains. The whole-genome sequence of DTMUV will help in understanding the epidemiology and molecular characteristics of duck Tembusu virus in southern China.
Subject(s)
Ducks , Flavivirus Infections/veterinary , Flavivirus/genetics , Genome, Viral/genetics , Poultry Diseases/epidemiology , Poultry Diseases/virology , Amino Acid Sequence , Animals , Base Sequence , China/epidemiology , Flavivirus Infections/epidemiology , Molecular Sequence Data , Sequence Analysis, DNA/veterinaryABSTRACT
We report here the complete genomic sequence of a novel porcine circovirus type 2 (PCV2) strain, which is supposed to be the result of natural genetic recombination between the ORF1 gene of genotype PCV2b-1B and the ORF2 gene of PCV2b-1C. Further analyses revealed that this novel PCV2 strain arose from recombination between PCV2a and PCV2b strains within the ORF2 gene. To our knowledge, this is the first report of both inter- and intragenotype PCV2 gene rearrangement in the field, and it will help in understanding the epidemiology and molecular characteristics of porcine circovirus type 2(PCV2) in southern China.
Subject(s)
Circovirus/genetics , Genome, Viral , Animals , Capsid/chemistry , China , Circoviridae Infections/virology , Genomics , Genotype , Molecular Sequence Data , Open Reading Frames , Sequence Analysis, DNA , SwineABSTRACT
We report here the complete genomic sequence of a novel duck hepatitis A virus (DHAV) isolated from mixed infections with DHAV type 1 (DHAV-1) and DHAV-3 in ducklings in Southern China. The whole nucleotide sequence had the highest homology with the sequence of DHAV-3 (GenBank accession number DQ812093) (96.2%). To our knowledge, this is the first report of gene rearrangement between DHAV-1 and DHAV-3, and it will help to understand the epidemiology and molecular characteristics of duck hepatitis A virus in Southern China.
