Effect of porcine circovirus type 2 (PCV2) load in serum on average daily weight gain during the postweaning period.

Porcine circovirus type 2 (PCV2) is a ubiquitous virus that mainly affects nursery and fattening pigs causing systemic disease (PCV2-SD) or subclinical infection. A characteristic sign in both presentations is reduction of average daily weight gain (ADWG). The present study aimed to assess the relationship between PCV2 load in serum and ADWG from 3 (weaning) to 21 weeks of age (slaughter) (ADWG 3-21).

Exploratory study on the influence of climatological parameters on Mycoplasma hyopneumoniae infection dynamics.

The objective of the present work was to elucidate the potential relationship between Mycoplasma hyopneumoniae infection and seroconversion dynamics and climatological conditions in four groups of pigs from the same farm born in different seasons of the year. Nasal swabs and blood samples were taken from 184 pigs at 1, 3, 6, 9, 12, 15, 18, 22 and 25 (slaughter age) weeks of age. Outside climatologic parameters, including temperature (°C), relative humidity (%), precipitation (l/m(2)) and wind speed (m/s) were recorded weekly from January 2003 to June 2004.

Post-weaning multisystemic wasting syndrome (PMWS) clinical expression under field conditions is modulated by the pig genetic background.

Post-weaning multisystemic wasting syndrome (PMWS) is a worldwide distributed disease of multifactorial origin and porcine circovirus type 2 (PCV2) has been identified as its essential infectious aetiology. Pig genetic background has been pointed to influence disease expression. In the present study, three different boar lines, namely A (100% Pietrain), B (50% Large White × 50% Pietrain) and C (25% Large White × 75% Duroc), were used to inseminate sows from the same genetic line (37.

Apoptosis in postweaning multisystemic wasting syndrome (PMWS) hepatitis in pigs naturally infected with porcine circovirus type 2 (PCV2).

The degree of apoptosis in the livers of pigs with hepatitis due to naturally-occurring postweaning multisystemic wasting syndrome (PMWS) was evaluated semi-quantitatively by immunohistochemical detection of the apoptotic marker cleaved caspase-3 (CCasp3). The amount and distribution of porcine circovirus type 2 (PCV2) virus in the liver was evaluated using in situ hybridisation. Livers with mild, stage I hepatitis exhibited similar degrees of apoptosis to controls; those with stage II lesions had variable apoptotic rates, ranging from mild to high, and in livers with more severe, stage III hepatitis, high levels of hepatocyte apoptosis was a feature.

Prevalence of infection with porcine circovirus-2 (PCV-2) and porcine reproductive and respiratory syndrome virus (PRRSV) in an integrated swine production system experiencing postweaning multisystemic wasting syndrome.

The objective of this study was to evaluate the prevalence of infection with porcine circovirus-2 (PCV-2) and porcine reproductive and respiratory syndrome virus (PRRSV) through a longitudinal study in an integrated swine production system (7 farms) experiencing postweaning multisystemic wasting syndrome (PMWS). Risk factors for PCV-2 infection and for PCV-2 and PRRSV coinfection were also evaluated. Fifteen sows from each herd and 4 non-cross-fostered piglets from each sow were randomly selected at farrowing and ear-tagged at birth.

Effect of sow vaccination against Mycoplasma hyopneumoniae on sow and piglet colonization and seroconversion, and pig lung lesions at slaughter.

The objectives of the present study were to compare Mycoplasma hyopneumoniae (Mh) colonization and serologic status on Mh vaccinated and non-vaccinated sows and to assess the effect of sow vaccination on colonization and serologic status of their piglets at weaning as well as presence of enzootic pneumonia (EP) lung lesions at slaughter. Fifty sows (25 vaccinated and 25 unvaccinated) as well as five of their piglets were included in the study. Blood samples and nasal swabs from sows at 7 weeks pre-farrowing and 1 week post-farrowing and from piglets at 3-4 weeks of age were taken.

A new method to identify cell types that support porcine circovirus type 2 replication in formalin-fixed, paraffin-embedded swine tissues.

Porcine circovirus type 2 (PCV2) is detected in high amounts within the characteristic microscopic lesions of postweaning multisystemic wasting syndrome (PMWS) affected pigs. In spite of recent advances on disease pathogenesis, the precise cell types that support viral replication are still a major issue of scientific discussion. In this study, a new methodology to detect cell types that support PCV2 replication was designed.

Chronological study of Mycoplasma hyopneumoniae infection, seroconversion and associated lung lesions in vaccinated and non-vaccinated pigs.

A field trial was conducted to study Mycoplasma hyopneumoniae (Mh) infection dynamics by nested polymerase chain reaction (nPCR) and serology in pigs of a farm affected by enzootic pneumonia (EP). Moreover, correlation of Mh detection at different respiratory tract sites with presence of EP gross and microscopic lung lesions was assessed. These parameters were studied and compared between vaccinated (two doses at 1 and 3 weeks of age versus one dose at 6 weeks of age) and non-vaccinated pigs.

Exploratory field study on Mycoplasma hyopneumoniae infection in suckling pigs.

The present study focused on Mycoplasma hyopneumoniae (M. hyopneumoniae) detection by nPCR in nasal swabs of 507 suckling pigs. These animals came from 69 sows (from 1 to 8 parity number) of a farrow-to-finish herd with Enzootic Pneumonia (EP) problems at finishing stages.

Sow porcine circovirus type 2 (PCV2) status effect on litter mortality in postweaning multisystemic wasting syndrome (PMWS).

Previous studies have described a "litter effect" associated with mortality in postweaning multisystemic wasting syndrome (PMWS) affected farms. The main objective of this study was to evaluate litter mortality in different PMWS affected farms and to characterize it in relation to three variables of the sow: parity, porcine circovirus type 2 (PCV2) infectious status and PCV2 antibody titres. The study was performed in seven farms that experienced PMWS in nurseries and/or fattening areas.

Genotypic diversity of Haemophilus parasuis field strains.

Haemophilus parasuis is the cause of Glässer's disease and other clinical disorders in pigs. It can also be isolated from the upper respiratory tracts of healthy pigs, and isolates can have significant differences in virulence. In this work, a partial sequence from the 60-kDa heat shock protein (Hsp60) gene was assessed as an epidemiological marker.

Detection of porcine circovirus type 1 in commercial pig vaccines using polymerase chain reaction.

The absence of extraneous viruses is a requirement in the quality control of vaccines for veterinary use in the European Pharmacopoeia. A polymerase chain reaction (PCR) assay for the detection of porcine circovirus type 1 (PCV1) and type 2 (PCV2) was evaluated in 18 commercial porcine vaccines. Since vaccine components may contain PCR enhancers or inhibitors, 13 of the studied vaccines (used as diluents) were subsequently spiked with different dilutions of PCV2 and tested by PCR.

Quantification of porcine circovirus type 2 (PCV2) DNA in serum and tonsillar, nasal, tracheo-bronchial, urinary and faecal swabs of pigs with and without postweaning multisystemic wasting syndrome (PMWS).

The present study focused on PCV2 quantification by TaqMan PCR in nasal (n=99), tonsillar (n=108), tracheo-bronchial (n=72), urinary (n=91) and faecal (n=42) swabs, as well as in serum (n=57), from a total of 146 pigs received at the Pathological Diagnostic Service at the Veterinary School of Barcelona (Spain). Animals were classified into three categories based on histopathological and in situ hybridisation (ISH) results: PMWS affected pigs (Group A, n=42), PCV2 subclinically infected pigs (Group B, n=29), and non-PMWS with PCV2 ISH negative pigs (Group C, n=75). Overall, tracheo-bronchial swabs had the higher PCV2 load followed by serum, tonsillar, nasal, faecal and, finally, urinary swabs.

Identification of viral pathogens in aborted fetuses and stillborn piglets from cases of swine reproductive failure in Spain.

The objective of the present study was to determine the presence of recognised abortifacient viruses such as porcine reproductive and respiratory virus (PRRSV), Aujeszky's disease virus (ADV), porcine parvovirus (PPV) and porcine circovirus type 2 (PCV2), in tissues from aborted fetuses and stillborn neonates in cases of late reproductive failure in swine. A total of 293 specimens (fetuses aborted in the last third of gestation and stillborn piglets) from 100 different cases of late-term abortions and premature farrowing from 15 different Spanish provinces were studied. PRRSV was detected in 9/100 cases by RT-PCR.

Apoptosis in lymphoid organs of pigs naturally infected by porcine circovirus type 2.

The objective of the present study was to evaluate the involvement of apoptosis in the development of post-weaning multisystemic wasting syndrome (PMWS) lymphoid-depletion lesions. Twenty-one pigs that were categorized into three different lesional severity stages (S1, n=5; S2, n=7; S3, n=9) and five healthy control pigs (stage S0) were used. From all pigs, samples of thymus, spleen, tonsil, ileum and superficial inguinal lymph node were processed for histological examination, in situ hybridization for porcine circovirus type 2 (PCV2) detection and cleaved caspase-3 (CCasp3) immunohistochemistry for detection of apoptotic cells.

Haptoglobin and pig-major acute protein are increased in pigs with postweaning multisystemic wasting syndrome (PMWS).

The objective of this study was to determine the serum concentration levels of selected acute phase proteins (APP), haptoglobin (HPT) and pig-major acute phase protein (pig-MAP), in postweaning multisystemic wasting syndrome (PMWS) affected pigs and PCV2-subclinically infected pigs. In a first study, a group of 15 eight-week-old conventional pigs from a PMWS affected farm were bled and a complete necropsy, histopathology and in situ hybridisation to detect PCV2 were performed. Based on the results, pigs were classified as suffering from PMWS (n = 10) or healthy animals (n = 5).

Postweaning multisystemic wasting syndrome (PMWS) in the Philippines: porcine circovirus type 2 (PCV2) detection and characterization.

Four swine facilities located in Northern Luzon, in the Philippines, showed lesions and clinical signs similar to those described in post weaning multisystemic wasting syndrome (PMWS). Post-mortem and histopathological examination revealed the presence of typical lymphoid lesions caused by porcine circovirus type 2 (PCV2). An in situ hybridization (ISH) technique allowed the detection of PCV2 nucleic acid associated with the lesions in target tissues.

In vitro and in vivo characterization of an infectious clone of a European strain of porcine circovirus type 2.

The aim of this study was to describe the generation of a PCV2 (porcine circovirus type 2) infectious clone (pIC-PCV2) and its infectivity under in vitro and in vivo conditions. The constructed pIC-PCV2 contained the whole PCV2 genome from a German isolate together with a partial duplication of 467 bp. PK-15 cells were transfected with pIC-PCV2 and an indirect immune fluorescence assay (IFA) was performed 7 days post-transfection.

Lack of an effect of a commercial vaccine adjuvant on the development of postweaning multisystemic wasting syndrome (PMWS) in porcine circovirus type 2 (PCV2) experimentally infected conventional pigs.

The objective of this study was to evaluate the effect of a commercial vaccine adjuvant on the clinical and pathological outcome of PCV2 experimentally infected 8 to 9-week-old conventional pigs. Forty-four pigs were divided into four groups: non-infected control pigs, pigs that received a vaccine adjuvant, pigs inoculated with PCV2, and pigs inoculated with PCV2 together with the vaccine adjuvant. Infection was monitored until 69 days post-inoculation (PI).

Comparison of porcine circovirus type 2 load in serum quantified by a real time PCR in postweaning multisystemic wasting syndrome and porcine dermatitis and nephropathy syndrome naturally affected pigs.

Postweaning multisystemic wasting syndrome (PMWS) diagnosis is based on the presence of characteristic histopathological lymphoid lesions and porcine circovirus type 2 (PCV2) within these lesions. Previous studies indicate that PCV2 load is higher in PMWS affected than in PCV2 infected, healthy pigs. On the other hand, PCV2 has been suggested to play a role in porcine dermatitis and nephropathy syndrome (PDNS) pathogenesis.

Dynamics of Mycoplasma hyopneumoniae infection in 12 farms with different production systems.

This study had 2 objectives: 1) to determine the involvement of Mycoplasma hyopneumoniae in respiratory outbreaks in herds of pigs, with the use of a nested polymerase chain reaction (nPCR) and an enzyme-linked immunosorbent assay (ELISA); and 2) to determine if the dynamics of M. hyopneumoniae infection differ between 3-site versus 1- or 2-site production systems (in which at least farrowing/gestation and nursery pigs are on the same site). Animals of different ages from 12 Spanish farms with respiratory problems were randomly sampled.