A novel virus, designated swine hepatitis E virus (swine HEV), was identified in pigs. Swine HEV crossreacts with antibody to the human capsid antigen. is a ubiquitous agent and majority of ≥3 months age herds from midwestern United States were seropositive. Young pigs naturally infected by clinically normal but had microscopic evidence hepatitis, developed viremia prior seroconversion. The entire ORFs 2 3 amplified reverse transcription–PCR sera putative gene (ORF2) shared about 79–80%...

The Lelystad virus or one of two US isolates (VR2385, VR2431) porcine reproductive and respiratory syndrome were given intranasally to 25 4-week-old cesarian-derived colostrum-deprived pigs. Pigs from these groups necropsied at 1, 2, 3, 5, 7, 10, 15, 21, 28 days postinoculation. VR2431 induced mild transient pyrexia, dyspnea, tachypnea. VR2385 labored rapid abdominal respiration, lethargy, anorexia, patchy dermal cyanosis. All three multifocal tan-mottled consolidation involving 6.8% (n = 9;...

Porcine circovirus type 2 (PCV2)–associated disease (PCVAD) continues to be an important differential diagnosis on pig farms in the United States and worldwide. Case trend analyses indicate that incidence of PCVAD is rise States. Accurate order implement appropriate intervention strategies. can manifest as a systemic disease, part respiratory complex, enteric porcine dermatitis nephropathy syndrome, or reproductive problems. may only sporadic individual animal diagnosis; however, also severe...

Prior to the recent discovery of swine hepatitis E virus (swine HEV) in pigs from midwestern United States, HEV was not considered endemic this country. Since is antigenically and genetically related human strains HEV, it important characterize new further. The infectivity titer a pool determined order prepare standardized reagent evaluate dose response pigs. Although sequence varied extensively those most very closely two (US-1 US-2) isolated States. U.S. which were recently recovered...

Hepatitis E virus (HEV) is a zoonotic pathogen of which pigs are reservoirs. To determine the presence HEV RNA in commercial pig livers sold local grocery stores USA, 127 packages liver were purchased and tested by universal RT-PCR assay capable detecting all four known genotypes. Among tested, 14 positive for RNA. Sequence phylogenetic analyses revealed that isolates belonged to genotype 3. An animal study was subsequently conducted whether PCR-positive still contained infectious virus. The...

The oldest porcine circovirus type 2 (PCV2) sequence dates back to 1962 and is among several hundreds of publicly available PCV2 sequences. Despite this resource, few studies have investigated the global genetic diversity PCV2. To evaluate phylogenetic relationship strains, 1680 open reading frame (ORF2) sequences were compared analysed by methods neighbour-joining, maximum-likelihood, Bayesian inference network analysis. Four distinct clades consistently identified included PCV2a, PCV2b,...

Hepatitis E virus (HEV) is an important public health concern in many developing countries. HEV also endemic some industrialized counties, including the United States. With our recent discovery of swine pigs that genetically closely related to human HEV, hepatitis now considered a zoonotic disease. Human strains are heterogenic. So far States, only one strain has been identified and characterized from pig. To determine extent genetic variations nature infections U.S. pigs, we developed...

Specific-pathogen-free pigs were inoculated with one of two hepatitis E viruses (HEV) (one recovered from a pig and the other human) to study relative pathogenesis in swine. Fifty-four randomly assigned three groups. Seventeen group 1 served as uninoculated controls, 18 2 intravenously swine HEV United States, 19 3 US-2 strain human patient States. Two four each necropsied at 3, 7, 14, 20, 27, or 55 days postinoculation (DPI). Evidence clinical disease elevation liver enzymes bilirubin was...

The objectives of this study were to investigate the interactions between Mycoplasma hyopneumoniae and porcine circovirus type 2 (PCV2) establish a model for studying pathogenesis testing intervention strategies control PCV2-associated respiratory disease complex (PRDC). Sixty-seven pigs randomly assigned four groups. Group 1 ( n = 17) served as controls, group inoculated with M. hyopneumoniae, 3 dual infected PCV2, 4 16) PCV2. Pigs intratracheally at weeks age followed by intranasal...

ABSTRACT An experimental model that demonstrates a mycoplasma species acting to potentiate viral pneumonia was developed. Mycoplasma hyopneumoniae , which produces chronic, lymphohistiocytic bronchopneumonia in pigs, found the severity and duration of virus-induced pigs. Pigs were inoculated with M. 21 days prior to, simultaneously with, or 10 after inoculation porcine reproductive respiratory syndrome virus (PRRSV), induces an acute interstitial PRRSV-induced clinical disease macroscopic...

Three-week-old cesarean-derived colostrum-deprived (CD/CD) pigs were inoculated with porcine circovirus type 2 (PCV2, n = 19), reproductive and respiratory syndrome virus (PRRSV, 13), concurrent PCV2 PRRSV (PCV2/PRRSV, 17), or a sham inoculum ( 12) to compare the independent combined effects of these agents. Necropsies performed at 7, 10, 14, 21, 35, 49 days postinoculation (dpi) when became moribund. By 10 dpi, PCV2/PRRSV-inoculated had severe dyspnea, lethargy, occasional icterus; after...

ABSTRACT Hepatitis E virus (HEV) is the major cause of enterically transmitted non-A, non-B hepatitis in many developing countries and also endemic industrialized countries. Due to lack an effective cell culture system a practical animal model, mechanisms HEV pathogenesis replication are poorly understood. Our recent identification swine from pigs affords us opportunity systematically study model. In early study, we experimentally infected specific-pathogen-free with two strains HEV: US-2...

ABSTRACT Swine infectious agents, especially viruses, are potential public health risks associated with the use of pig organs for xenotransplantation in humans. Therefore, there is a need better characterization swine viruses and development diagnostic tests their detection. We report here isolation novel strain porcine circovirus (PCV) from pigs postweaning multisystemic wasting syndrome (PMWS). Affected exhibited severe interstitial pneumonia lymphoid depletion. The complete nucleotide...

One hundred forty-six 5-week-old cesarean-derived, colostrum-deprived (CDCD) pigs were inoculated intranasally with 1 of 9 US porcine reproductive and respiratory syndrome virus (PRRSV) isolates. Differences found in severity clinical disease, rectal temperatures ( P ≤0.001), gross lung lesions ≤ 0.001), microscopic 0.05). Gross generally most severe 10 days postinoculation distributed primarily the cranial, middle, accessory lobes ventromedial portion caudal lobes. Mean lesion scores...

ABSTRACT Postweaning multisystemic wasting syndrome (PMWS) is an emerging disease in swine. Increasing evidence indicates that a variant strain of porcine circovirus (PCV), designated type 2 PCV (PCV-2), responsible for PMWS. To determine the extent genetic heterogeneity PCV-2 isolates, complete genomes six isolates from different regions North America were amplified by PCR and sequenced. Sequence phylogenetic analyses confirmed two distinct genotypes exist: nonpathogenic genotype PCV-1...

ABSTRACT Infection of animals with a molecular viral clone is critical to study the genetic determinants replication and virulence in host. Type 2 porcine circovirus (PCV2) has been incriminated as cause postweaning multisystemic wasting syndrome (PMWS), an emerging disease pigs. We report here for first time construction use infectious DNA PCV2 characterize pathologic lesions associated infection by direct vivo transfection pigs clone. The was generated ligating two copies complete genome...

The objective of this study was to determine whether vaccination with bacterins commonly used in the USA, when administered at a time typical US protocol, enhances porcine circovirus type 2 (PCV2) replication and incidence severity clinical signs lesions characteristic postweaning multisystemic wasting syndrome (PMWS) conventional pigs. Sixty-one pigs free PCV2 were randomly assigned four groups. Groups 1 ( n = 15) served as sham-inoculated negative controls. 3 14) 4 17) inoculated...

ABSTRACT Porcine circovirus type 2 (PCV2) is associated with postweaning multisystemic wasting syndrome in pigs, whereas PCV1 nonpathogenic. We previously demonstrated that a chimeric PCV1-2 virus (with the immunogenic capsid gene of PCV2 cloned into backbone PCV1) induces an antibody response to protein and attenuated pigs. Here, we report protective immunity wild-type challenge A total 48 specific-pathogen-free piglets were randomly equally assigned four groups 12 pigs each. Pigs group 1...

ABSTRACT Porcine reproductive and respiratory syndrome virus (PRRSV) is the most important infectious disease agent of pigs worldwide, causing failure in pregnant sows problems nursing growing pigs. PRRSV infection characterized by a prolonged viremia 30 or more days an extended persistent lymphoid tissues. To better understand immunological basis for acute infection, we have examined cell-mediated immune (CMI) response throughout course compared results to local distribution abundance...