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Porcine Circovirus-2 (PCV-2) is an emerging swine infection responsible for significant financial losses in the global swine industry. It has a significant negative impact on reproductive performance causing abortion, stillbirth, and other anomalies. As there is limited knowledge related to the histopathology of male and female reproductive systems in PCV-2 infected pigs, the current study was designed. Swine carcasses presented for post-mortem examination with a history of respiratory distress, anorexia, diarrhoea, wasting, and paleness of the skin collected from mid of 2021 to mid of 2022 from different parts of Kerala, India, were utilised in this study. The samples were initially screened with polymerase chain reaction (PCR) and were subjected to gross and histopathological studies. Out of 65 collected samples, 10 were positive for PCV-2 by PCR. The positive sample carcasses were emaciated, had poor body condition with visible bony prominences, decreased back fat thickness, rough, long hair coat, and sunken eyes. Mild oedema and congestion were seen in the testes, epididymis, and vas deferens of the male reproductive system and on accessory reproductive glands such as the bulbourethral gland, prostate gland, and seminal vesicle. In the female reproductive system, the ovary, oviduct, and uterus had mild congestion and oedema in most cases. Histopathology of the male reproductive system revealed mild degenerative changes, haemorrhage, and congestion in all cases. The vasa deferentia showed a loss of cilia in the pseudostratified columnar epithelium. The female reproductive organs had congestion, degenerative changes, and infiltration of mononuclear cells. For further confirmation, localisation of PCV-2 antigen was done in reproductive organs with immunohistochemistry (IHC). History, gross, histopathological findings, and PCR in combination with IHC highlight the pathologic effects of PCV-2 on reproductive organs in infected pigs.

Porcine Circovirus-2 (PCV-2) is an emerging swine infection responsible for significant financial losses in the global swine industry. It has a significant negative impact on reproductive performance causing abortion, stillbirth, and other anomalies. As there is limited knowledge related to the histopathology of male and female reproductive systems in PCV-2 infected pigs, the current study was designed. Swine carcasses presented for post-mortem examination with a history of respiratory distress, anorexia, diarrhoea, wasting, and paleness of the skin collected from mid of 2021 to mid of 2022 from different parts of Kerala, India, were utilised in this study. The samples were initially screened with polymerase chain reaction (PCR) and were subjected to gross and histopathological studies. Out of 65 collected samples, 10 were positive for PCV-2 by PCR. The positive sample carcasses were emaciated, had poor body condition with visible bony prominences, decreased back fat thickness, rough, long hair coat, and sunken eyes. Mild oedema and congestion were seen in the testes, epididymis, and vas deferens of the male reproductive system and on accessory reproductive glands such as the bulbourethral gland, prostate gland, and seminal vesicle. In the female reproductive system, the ovary, oviduct, and uterus had mild congestion and oedema in most cases. Histopathology of the male reproductive system revealed mild degenerative changes, haemorrhage, and congestion in all cases. The vasa deferentia showed a loss of cilia in the pseudostratified columnar epithelium. The female reproductive organs had congestion, degenerative changes, and infiltration of mononuclear cells. For further confirmation, localisation of PCV-2 antigen was done in reproductive organs with immunohistochemistry (IHC). History, gross, histopathological findings, and PCR in combination with IHC highlight the pathologic effects of PCV-2 on reproductive organs in infected pigs. [ABSTRACT FROM AUTHOR]

Abstract Porcine circovirus‐like virus P1, like porcine circovirus type 2 (PCV2), is a potential pathogen of post‐weaning multisystemic wasting syndrome in swine. Yaks are a valuable species and an iconic symbol of the Tibet Plateau which is the highest and largest plateau in the world. In this study, a total of 105 yak diarrheal samples, collected from 13 farms in Linzhi in the Tibet Plateau from January 2019 to December 2021, that were screened for P1 and PCV2 by polymerase chain reaction, 10.48% (n = 11) were positive for P1, 4.76% (n = 5) for PCV2, and 5.71% (n = 6) were positive for coinfection of P1 and PCV2. In addition, the whole genomes of eight P1 strains and eight PCV2 strains were sequenced. Alignment of deduced amino acid sequences of P1 ORF1 and PCV2 ORF2 gene revealed that ON012566 had one unique amino acid mutation at residues 137 (T to P). This mutation has important implication for the study of virus virulence, tissue tropism, and immune response. Phylogenetic analysis shows that the yak‐origin P1 strains in this study with cattle‐origin P1 reference strains were grouped into one cluster. The yak‐origin PCV2 (ON012566) and a buffalo‐origin PCV2 (KM116514) reference strain clustered in the same branch in the PCV2b regions. Meanwhile, the remaining PCV2 strains and buffalo‐origin PCV2 reference strain (ON012565) clustered in the PCV2d regions. To summarize, to our knowledge, this is the first report on the molecular prevalence and genome characteristics of P1 and PCV2 in yaks in the world and will contribute to further study of the molecular epidemiology, source, and evolution of P1 and PCV2 strains.

Like in many other African countries, pig production is increasing in Tanzania. To support farmers and stakeholders, it is important to increase our understanding of porcine pathogens present in the country. Currently, little is known about the circulation of porcine circovirus-2 (PCV-2) and porcine circovirus-3 (PCV-3). For this reason, samples from 124 pigs collected throughout the country between 2018 to 2022 were screened by PCR for the presence of PCV-2 and PCV-3. Sequencing and phylogenetic analysis of positive amplicons identified two PCV-2 genotypes (a and d). Limited genetic heterogenicity was observed among the PCV-3. This study provides important data on pathogens present in pigs in Tanzania and should be of use veterinary authorities involved in porcine disease management. [ABSTRACT FROM AUTHOR]

Porcine circovirus‐like virus P1, like porcine circovirus type 2 (PCV2), is a potential pathogen of post‐weaning multisystemic wasting syndrome in swine. Yaks are a valuable species and an iconic symbol of the Tibet Plateau which is the highest and largest plateau in the world. In this study, a total of 105 yak diarrheal samples, collected from 13 farms in Linzhi in the Tibet Plateau from January 2019 to December 2021, that were screened for P1 and PCV2 by polymerase chain reaction, 10.48% (n = 11) were positive for P1, 4.76% (n = 5) for PCV2, and 5.71% (n = 6) were positive for coinfection of P1 and PCV2. In addition, the whole genomes of eight P1 strains and eight PCV2 strains were sequenced. Alignment of deduced amino acid sequences of P1 ORF1 and PCV2 ORF2 gene revealed that ON012566 had one unique amino acid mutation at residues 137 (T to P). This mutation has important implication for the study of virus virulence, tissue tropism, and immune response. Phylogenetic analysis shows that the yak‐origin P1 strains in this study with cattle‐origin P1 reference strains were grouped into one cluster. The yak‐origin PCV2 (ON012566) and a buffalo‐origin PCV2 (KM116514) reference strain clustered in the same branch in the PCV2b regions. Meanwhile, the remaining PCV2 strains and buffalo‐origin PCV2 reference strain (ON012565) clustered in the PCV2d regions. To summarize, to our knowledge, this is the first report on the molecular prevalence and genome characteristics of P1 and PCV2 in yaks in the world and will contribute to further study of the molecular epidemiology, source, and evolution of P1 and PCV2 strains. [ABSTRACT FROM AUTHOR]

Porcine circovirus‐2 (PCV‐2) is associated with several disease syndromes in domestic pigs that have a significant impact on global pig production and health. Currently, little is known about the status of PCV‐2 in Africa. In this study, a total of 408 archived DNA samples collected from pigs in Burkina Faso, Cameroon, Cape Verde, Ethiopia, the Democratic Republic of the Congo, Mozambique, Nigeria, Senegal, Tanzania and Zambia between 2000 and 2018 were screened by PCR for the presence of PCV‐2. Positive amplicons of the gene encoding the viral capsid protein (ORF2) were sequenced to determine the genotypes circulating in each country. Four of the nine currently known genotypes of PCV‐2 were identified (i.e. PCV‐2a, PCV‐2b, PCV‐2d and PCV‐2 g) with more than one genotype being identified in Burkina Faso, Ethiopia, Nigeria, Mozambique, Senegal and Zambia. Additionally, a phylogeographic analysis which included 38 additional ORF2 gene sequences of PCV‐2s previously identified in Mozambique, Namibia and South Africa from 2014 to 2016 and 2019 to 2020 and available in public databases, demonstrated the existence of several African‐specific clusters and estimated the approximate time of introduction of PCV‐2s into Africa from other continents. This is the first in‐depth study of PCV‐2 in Africa and it has important implications for pig production at both the small‐holder and commercial farm level on the continent. [ABSTRACT FROM AUTHOR]

Porcine circovirus-2 (PCV2) is the primary agent of Postweaning Multisystemic Wasting Syndrome (PMWS), and is associated with Porcine Circovirus Associated Disease, which causes great economic losses in pig breeding. PCV2 infection is distributed worldwide throughout the domestic pig population. There have not been any investigations on the distribution of PCV2 sero-prevalence in the population of pigs in Latvia. However PCV2 is one of main differential infections for many diseases, and therefore it is very variable in clinical presentation of PMWS and other diseases associated with PCV2. The objective of this study was to investigate the seroprevalence of PCV2 in pigs of different-scale farms located in different regions of Latvia. Blood samples of 963 pigs from 58 different-scale farms were examined for the PCV2 antibody from 2006 to 2016. It can be suggested that PCV2 is widespread within the territory of Latvia. Farms with pig number of up to 10 and farms with more than 5000 animals have different levels of biosafety, housing conditions and herd management. Nevertheless, the study showed that the number of PCV2-seropositive animals is similar in all farms (from 70.0% to 79.7%). [ABSTRACT FROM AUTHOR]

Porcine circovirus–associated disease, caused primarily by Porcine circovirus 2 (PCV-2), has become endemic in many pig-producing countries and has resulted in significant economic losses to the swine industry worldwide. Tests for PCV-2 infection include PCR, nested PCR, competitive PCR, and real-time PCR (rtPCR). Recombinase polymerase amplification (RPA) has emerged as an isothermal gene amplification technology for the molecular detection of infectious disease agents. RPA is performed at a constant temperature and therefore can be carried out in a water bath. In addition, RPA is completed in ~30 min, much faster than PCR, which usually takes >60 min. We developed a RPA-based method for the detection of PCV-2. The detection limit of RPA was 102 copies of PCV-2 genomic DNA. RPA showed the same sensitivity as rtPCR but was 10 times more sensitive than conventional PCR. Successful amplification of PCV-2 DNA, but not other viral templates, demonstrated high specificity of the RPA assay. This method was also validated using clinical samples. The results showed that the RPA assay had a diagnostic agreement rate of 93.7% with conventional PCR and 100% with rtPCR. These findings suggest that the RPA assay is a simple, rapid, and cost-effective method for PCV-2 detection, which could be potentially applied in clinical diagnosis and field surveillance of PCV-2 infection. [ABSTRACT FROM AUTHOR]

Sensitive detection of Porcine circovirus-2 (PCV-2) is very important for surveillance of postweaning multisystemic wasting syndrome. Droplet digital polymerase chain reaction (ddPCR) is novel PCR method that can achieve high precision. Our study aimed to develop a sensitive assay utilizing ddPCR to detect PCV-2. Specificity of the assay was confirmed by the failure of amplification of DNA of other relevant viruses. The detection limit for ddPCR was 25 copies/μL, a 4-fold greater sensitivity than TaqMan real-time PCR. Both methods showed a high degree of linearity (R2 = ~1), although TaqMan real-time PCR showed less sensitivity than ddPCR for clinical detection. Our findings indicate that ddPCR might represent a promising platform for detecting PCV-2 viral loads. [ABSTRACT FROM AUTHOR]

A recombinant replication-defective adenovirus expressing the major epitopes of porcine circovirus-2 (PCV-2) capsid protein (rAd/Cap/518) was previously constructed and shown to induce mucosal immunity in mice following intranasal delivery. In the present study, immune responses induced by intranasal immunization with a combination of rAd/Cap/518 and cytosine-phosphate-guanosine oligodeoxynucleotides (CpG ODN) were evaluated in mice. The levels of PCV-2-specific IgG in serum and IgA in saliva, lung, and intestinal fluids were significantly higher in the group immunized with rAd/Cap/518 and CpG ODN than animals immunized with rAd/Cap/518 alone. The frequencies of IL-2-secreting CD4+ T cells and IFN-γ-producing CD8+ T cells were significantly higher in the combined immunization group than mice immunized with rAd/Cap/518 alone. The frequencies of CD3+, CD3+CD4+CD8-, and CD3+CD4-CD8- T cells in the combined immunization group were similar to that treated with CpG ODN alone, but significantly higher than mice that did not receive CpG ODN. PCV-2 load after challenge in the combined immunization group was significantly lower than that in the phosphate-buffered saline placebo group and approximately 7-fold lower in the group treated with CpG ODN alone. These results indicate that rAd/Cap/518 combined with CpG ODN can enhance systemic and local mucosal immunity in mice, and represent a promising synergetic mucosal vaccine against PCV-2. [ABSTRACT FROM AUTHOR]

A rapid (<5 min) immunochromatographic strip using a colloidal gold–labeled antigen probe was successfully developed and applied for the detection of Porcine circovirus-2 (PCV-2) antibodies in swine. Recombinant Cap protein truncated nuclear localization signal of PCV-2, was expressed and labeled with colloidal gold. This conjugate was dispensed on a conjugate pad as the detector. Staphylococcal protein A and purified porcine anti–PCV-2 antibodies were blotted on a nitrocellulose membrane for the test and control lines, respectively. Sensitivity and specificity of this strip test was evaluated using PCV-2 antisera as well as other sera from pigs infected with a variety of swine viruses. For the validation of this strip test, 500 clinical swine serum samples were assessed both by the strip and a commercial enzyme-linked immunosorbent assay (ELISA) kit. The agreement between the immunochromatographic strip and ELISA kit was 94.00%. This strip possesses high sensitivity and specificity and may be useful as a candidate for rapid diagnosis of PCV-2 antibodies in the field. [ABSTRACT FROM PUBLISHER]

Porcine circovirus-2 (PCV-2) serology is commonly used for PCV-2 herd status determination and optimal timing of PCV-2 vaccination programs. The objectives of the current study were to develop an in-house indirect enzyme-linked immunosorbent assay (ELISA) using a recombinant nuclear localization signal truncated capsid (rntCap) protein expressed in an Escherichia coli system and to determine the diagnostic performance of the developed rntCap indirect ELISA in comparison with immunoperoxidase monolayer assays (IPMAs). Based on a receiver operating characteristic (ROC) curve analysis of the rntCap indirect ELISA (n = 90), an optimum cutoff optical density (OD) of 0.330 was determined, which resulted in diagnostic sensitivity, diagnostic specificity, and accuracy of 98.33%, 93.33%, and 96.67%, respectively. Average OD values of the positive (n = 8) and negative sera (n = 8) tested by either purified glutathione-S-transferase (GST) protein or the rntCap protein as the coating antigen revealed that the mean OD values tested by the rntCap indirect ELISA were significantly different from using GST alone (P < 0.005). The correlation between the established rntCap indirect ELISA and the IPMA results demonstrated as the linear regression (Spearman correlation coefficient = 0.772, P < 0.005) indicated that the OD ratio obtained from the rntCap indirect ELISA could be used to predict the levels of the IPMA titers. More samples are needed for enhancing the diagnostic sensitivity, specificity and accuracy. In conclusion, the establishment of the rntCap indirect ELISA could be used as a serodiagnostic assay for large-scale detection of PCV-2 antibodies in swine and has the capability to be produced commercially for routine use in diagnostic laboratories. [ABSTRACT FROM PUBLISHER]

The article shows the function of Bovine viral diarrhea virus (BVDV) in progression of Porcine circovirus-2 (PCV-2). Two studies were performed, where the first one involved vaccination of germ-free pigs vaccinated with different PCV-2 and BVDV viruses. The second study looked at cesarian-derived, colostrum-derived pigs that were vaccinated with the viruses. Results showed that BVDV and PCV-2 hinder growth and caused death of pigs through developing acute respiratory distress.

The article discusses a study that evaluated Porcine circovirus-2 (PCV-2) polymerase chain reaction (PCR) data taken after application of different DNA extraction methods to lymph node specimens. It cites the evaluation of 3 manual DNA extraction methods namely the DNeasy tissue kit, a modified in-house silica-based affinity protocol and DNAzol reagent. It indicate that the DNA extraction method affects PCV-2 quantification in lymph node samples by qPCR.

The article discusses a study on a competitive polymerase chain reaction (cPCR) and SYBR Green based real time-time PCR developed to establish a suitable method in determining the amount of PCV-2 DNA in swine tissue samples from post-weaning multisystemic wasting syndrome (PMWS)-affected or healthy pigs. Tissue samples from pigs with clinical signs of PMWS were taken. It suggests that ePCR and SYBR Green real-time PCR can be used to discriminate between PMWS-affected and non-affected pigs.

The article assesses the applicability of quantitative polymerase chain reaction (qPCR) to quantify Porcine circovirus-2 (PCV-2) loads in pooled serum samples as an easy-to-use postweaning multisystemic wasting syndrome (PMWS) diagnostic tool at the herd level. The study revealed that targeted sampling did not result in better estimations than random sampling. The researchers pointed out that the possibility to discriminate between truly PMWS cases and non-PMWS cases in a targeted sampling manner was compromised.

The article presents a study which conducted a blinded interlaboratory assessment of the diagnostic agreement and accuracy of serologic tests for routine detection of antibodies against Porcine circovirus-2 (PCV-2) in several North American laboratories. The study found that kappa analysis revealed differences among the laboratories. The indirect fluorescent antibody tests (IFAT) in the first two laboratories and the in-house enzyme-linked immunosorbent assays (ELISA) used in the fifth laboratory detected the highest number of positive samples.

Summary: Systemic toxoplasmosis and concurrent infection with porcine circovirus-2 (PCV-2) was diagnosed in a fattening pig. Clinical examination of the herd showed that up to 30% of the pigs of this weight group suffered from severe respiratory signs including sneezing and coughing, with a mortality rate of up to 5%. Gross necropsy examination revealed severe interstitial pneumonia and generalized lymphadenopathy. On microscopical examination there was necrotizing inflammation of the lung, adrenal glands and lymph nodes, associated with lymphoid depletion, cytoplasmic basophilic botryoid inclusion bodies and protozoal microorganisms. Infection with Toxoplasma gondii was confirmed by immunohistochemistry (IHC). Polymerase chain reaction analysis, in-situ hybridization and IHC confirmed systemic PCV-2 infection. These findings, associated with the respiratory signs and lesions in lymphoid tissues, are characteristic for post-weaning multisystemic wasting syndrome (PMWS). In this case, immunosuppression by PCV-2 may have triggered systemic toxoplasmosis, or immune stimulation caused by coinfection with T. gondii may have caused extensive replication of PCV-2. [Copyright &y& Elsevier]

This study aimed to survey captive wild boars for antibodies against Porcine circovirus-2 ( PCV-2) in registered farms. Serum samples ( n = 1305) were collected from 90-day-old wild boars from 118 farms of the Brazilian South-east region, including the states of Minas Gerais and São Paulo, and South region, including the states of Paraná, Rio Grande do Sul and Santa Catarina. All herds (100%) presented reactive animals, in varying numbers and from low-to-high antibody titres, with the occurrence ranging from 82 to 89%. Considering farms, the average prevalence was of 84.9% ( P < 0.05) and ranged from 54.1 to 94.95%. Regarding the geographic regions studied, the prevalence was of 100%, with PCV2 antibodies detected in wild boars of all regions. This study provides the first evidence of PCV2 antibodies in captive wild boars in Brazil. [ABSTRACT FROM AUTHOR]

An outbreak of exudative epidermitis (EE) among piglets in a Swedish SPF-herd initiated a survey for indications as to the cause of disease.The herd was established by caesarean section and has been closed to all new animal material, with the exception of semen for artificial insemination (AI). The study comprised serum samples from the SPF-herd over a 10-year period (n=109) and a close monitoring of animals in the herd during the period after the EE outbreak. Serum samples from conventional boars at the AI-station servicing the herd were also included (n=9). All serum samples were tested for antibodies to porcine circovirus-2 (PCV-2). In addition, 3-week-old piglets from three litters (n=24) farrowed close after the initial EE outbreak were closely monitored for clinical signs of skin disease, sampled for Staphylococcus hyicus, tested for antibodies to porcine parvovirus and in sequentially collected serum samples tested for interferon-α (IFN-α) and interleukin-6.The PVC-2 serology showed that animals in the herd were sero-negative at least until 2 months prior to the EE outbreak. During the period close after the EE outbreak the animals showed varying levels of antibodies to PCV-2 but all the tested animals had sero-converted 4 months later. The AI boars were also sero-positive to PCV-2 at the time of the EE outbreak. Animals in the SPF-herd remained sero-positive to PCV-2 during the following 7 years. In the monitored litters, one piglet had clinical EE and 15 piglets displayed defined erythemas on the abdomen. Fourteen of the piglets also had IFN-α in serum on one or more occasions during the study, indicating viral activity among the animals. S. hyicus was isolated from all of the piglets from the earliest sampling point (3 days of age) and onwards, irrespective of clinical signs. PCV-2 was isolated from lymphnode tissue collected from one of the EE affected pigs.Further, increases in the number of stillborn piglets, small litters (<6 piglets) and repeat breeders could be correlated to the time of PCV-2 sero-conversion. Coincidence of active viral infection and sero-conversion to PCV-2 points to the virus as the cause of the EE outbreak and reproductive disturbances. [Copyright &y& Elsevier]

The article discusses research on the differences between the genotypes Porcine circovirus (PCV) in paraffin-embedded as well as formalin-fixed tissues in pigs. It references a study by Chanhee Chae and colleagues, published in the 2010 issue of the "Journal of the Veterinary Diagnostic Investigation." The researchers examined the genotypes using in situ hybridization assay. They found that PCV is commonly associated with pigs that are infected with chronic bronchointerstitial pneumonia.