scholarly journals Epidemiological investigation of porcine circovirus type 2 and its coinfection rate in Shandong province in China from 2015 to 2018

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Zicheng Ma ◽  
Mengda Liu ◽  
Zhaohu Liu ◽  
Fanliang Meng ◽  
Hongyu Wang ◽  
...  

Abstract Background Porcine circovirus type 2 (PCV2) is one of the crucial swine viral pathogens, caused porcine circovirus associated diseases (PCVAD). Shandong province is one of the most important pork producing areas and bears a considerable economic loss due to PCVAD. However, there is limited information on epidemiology and coinfection rate of PCV2 with other critical swine diseases in this area, such as porcine reproductive and respiratory syndrome virus (PRRSV), classical swine fever virus (CSFV), Pseudorabies virus (PRV), and porcine epidemic diarrhea virus (PEDV). Results Overall, 89.59% serum samples and 36.98% tissue samples were positive for PCV2 specified ELISA and PCR positive for PCV2, respectively. The coinfection rates of PCV2 with PRRSV, PRV, CSFV, and PEDV were 26.73%, 18.37%, 13.06%, and 3.47%, respectively. Moreover, genetic characteristic of PCV2 were analyzed based on the cap genes showing that PCV2d is the dominant sub-genotype circulating in the province. Conclusions Our findings reveal that PCV2d, as the dominant strain, is prevailing in pig farms in Shandong province at high levels. There was a high frequency of coinfection of PCV2 and PRRSV.

Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 891
Author(s):  
Jeongmin Suh ◽  
Taehwan Oh ◽  
Keehwan Park ◽  
Siyeon Yang ◽  
Hyejean Cho ◽  
...  

The aim of this study was to compare the virulence of porcine circovirus type 2 (PCV2) genotypes in dually inoculated pigs with both three genotypes (a, b, and d) of PCV2 and porcine reproductive and respiratory syndrome virus-2 (PRRSV-2) versus pigs singularly inoculated with the same three PCV2 genotypes (a, b, and d). Differences in this comparison were found in PCV2 viremia levels, lung and lymphoid lesion severity, and the amount of PCV2 antigen within the lymphoid lesions. Regardless of PCV2 genotypes, pigs that were dually inoculated with PCV2/PRRSV had significantly higher clinical scores, less average daily weight gain, higher levels of PCV2 viremia, and more severe lug and lymphoid lesions compared to pigs singularly inoculated with PCV2. Among the dually infected pig groups, pigs infected with PCV2d/PRRSV-2 had significantly higher levels of PCV2 viremia, more severe lung and lymphoid lesions, and more PCV2-positive cells within lymphoid lesions compared to pigs dually inoculated with PCV2a/PRRSV-2 and PCV2b/PRRSV-2. The results of this study demonstrated significant differences in the virulence among dual inoculation of PCV2a/PRRSV-2, PCV2b/PRRSV-2, and PCV2d/PRRSV-2. A significant difference in the virulence among PCV2a, PCV2b, and PCV2d single-inoculated pig groups was not found with respect to the levels of PCV2 viremia and production of PCV2-associated lymphoid lesions.


2009 ◽  
Vol 16 (6) ◽  
pp. 830-834 ◽  
Author(s):  
D. M. Madson ◽  
A. R. Patterson ◽  
S. Ramamoorthy ◽  
N. Pal ◽  
X. J. Meng ◽  
...  

ABSTRACT The aims of this study were to determine if porcine circovirus type 2 (PCV2) vaccination of the dam is effective in preventing fetal PCV2 infection and reproductive failure. Twelve pregnant, PCV2-naïve sows were randomly divided into four groups, with three sows in each group. Group 1 sows served as noninoculated, nonvaccinated negative controls, group 2 sows were vaccinated with a commercially available PCV2 vaccine at 28 days of gestation and were not inoculated, group 3 sows were vaccinated at 28 days of gestation and inoculated with PCV2b at 56 days of gestation, and group 4 sows were inoculated with PCV2b but were not vaccinated. Serum samples from all sows were collected weekly throughout the gestation period, and sows were allowed to farrow naturally. At parturition, sow colostrum samples, presuckle serum samples, and tissues from the piglets were collected. Reproductive failure was not observed under the study conditions. PCV2 vaccination induced PCV2-specific immunoglobulin G and serum neutralizing antibodies in sows from groups 2 and 3 and prevented detectable PCV2 viremia in the dams after challenge. In group 3, PCV2 DNA was detected in colostrum samples, fetuses, and live-born pigs; however, microscopic lesions and PCV2-specific antigen were not present in any of the fetuses in this group. The results from this study indicate that vertical transmission of PCV2 can occur in PCV2-vaccinated dams.


2020 ◽  
Vol 161 ◽  
pp. 01063
Author(s):  
Larisa A. Neminuschaya ◽  
Natalia K. Eremets ◽  
Tatyana A. Skotnikova ◽  
Igor V. Pavlenko ◽  
Vladimir I. Eremets ◽  
...  

The paper deals with the results of assessing the intensity of PCV2 (porcine circovirus type 2) circulation in pigs of different age groups on pig farms in the Russian Federation. Serum samples of 128 pigs of different age groups from two pig farms in the Russian Federation were studied. As a result, specific antibodies to PCV2 were detected that proves virus circulation. Average titer of serum antibodies was 1:2020 for weaning piglets, 40 d.a. (days of age), in prenursery piglets of the age of 20 days - 1:3120; in replacement gilts of the age of 175 days - 1: 5124; in feeding pigs of the age of 180 days - 1:5300. In female pigs, the percentage of seroprevalence was 95 %. With advancing ageing of pigs, the level of antibody titer to PCV2 was increasing that proves the animals were infected after the decrease of colostral antibody level below protective one.


2018 ◽  
Vol 63 (No. 8) ◽  
pp. 358-366
Author(s):  
LL Zheng ◽  
XH Jin ◽  
FS Wei ◽  
CQ Wang ◽  
HY Chen ◽  
...  

Porcine parvovirus, porcine pseudorabies virus and porcine circovirus type 2 can cause reproductive failure in pigs, and swine are often simultaneously infected by combinations of the three viruses. We here report the development of a SYBR Green I-based multiplex real time PCR assay for simultaneous detection of porcine parvovirus, porcine pseudorabies virus and porcine circovirus type 2. Three pairs of specific primers were designed for the porcine parvovirus-VP2, porcine pseudorabies virus-gH and porcine circovirus type 2-ORF2 genes. Viral genomes were identified based on their distinctive melting temperatures in singleplex PCR reactions. The melting temperature was 74.5 °C for the 313 bp amplicon of porcine parvovirus-VP2 gene, 87.5 °C for the 355 bp amplicon of porcine pseudorabies virus-gH gene and 80.5 °C for the 171 bp amplicon of the porcine circovirus type 2-ORF2 gene, respectively. The detection limit of the method ranged from 0.01–0.03 TCID<sub>50</sub>/ml for the three viruses. In addition, porcine parvovirus, porcine pseudorabies virus and porcine circovirus type 2 viral loads were measured in 100 field samples, and the result showed that the concordance between real-time PCR and conventional PCR was 60.42%. The sensitivity and specificity of real-time PCR were 100% and 100%, while those of conventional PCR were 40.83% and 72.22%, respectively.


2014 ◽  
Vol 95 (11) ◽  
pp. 2486-2494 ◽  
Author(s):  
Changhoon Park ◽  
Hwi Won Seo ◽  
Su-Jin Park ◽  
Kiwon Han ◽  
Chanhee Chae

The objective of this study was to compare the virulence and pathogenicity of a combination of concurrent infections of two genotypes of porcine circovirus type 2 (PCV2) and two genotypes of porcine reproductive and respiratory syndrome virus (PRRSV) in terms of PCV2 viraemia, and PCV2-associated lesions and antigens in co-infected pigs. Pigs with PCV2a (or 2b)/type 1 (or type 2) PRRSV had significantly (P<0.05) higher mean clinical respiratory scores and lower average daily weight gain compared with pigs with PCV2a (or 2b). Co-infection induced significantly lower levels of anti-PCV2 and anti-PRRSV IgG antibodies than infection with one genotype alone, regardless of the genotype of the two viruses. Pigs with PCV2a (or 2b)/type 2 PRRSV had significantly (P<0.05) higher levels of PCV2 viraemia, more severe PCV2-associated lesions, and more PCV2 DNA within the lesions compared with pigs with PCV2a (or 2b)/type 1 PRRSV. However, there was no significant difference in these parameters in pigs with PCV2a/type 2 PRRSV or PCV2b/type 2 PRRSV. The results of this study demonstrate significant differences in the virulence and pathogenicity of type 1 and type 2 PRRSV but no significant differences in the virulence and pathogenicity of PCV2a and PCV2b with respect to the production of PCV2-associated lesions.


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