Detection of <i>Cryptosporidium parvum </i>Pig Genotype Ⅱ and <i>Cryptosporidium suis </i>from Growing-Fattening Pigs Infected with Porcine Circovirus Type 2, and Porcine Reproductive and Respiratory Syndrome Virus in Growing-Fattening Pigs

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.

Download Full-text

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

BMC Veterinary Research ◽

10.1186/s12917-020-02718-4 ◽

2021 ◽

Vol 17 (1) ◽

Author(s):

Zicheng Ma ◽

Mengda Liu ◽

Zhaohu Liu ◽

Fanliang Meng ◽

Hongyu Wang ◽

...

Keyword(s):

Pseudorabies Virus ◽

Porcine Circovirus Type ◽

Porcine Circovirus Type 2 ◽

Shandong Province ◽

Porcine Circovirus ◽

Respiratory Syndrome Virus ◽

Limited Information ◽

Serum Samples ◽

Diarrhea Virus

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.

Download Full-text

Research of immune response in unvaccinated piglets against porcine circovirus type 2

Veterinarski glasnik ◽

10.2298/vetgl1402067s ◽

2014 ◽

Vol 68 (1-2) ◽

pp. 67-76

Author(s):

Ognjen Stevancevic ◽

Nenad Stojanac ◽

Aleksandar Potkonjak ◽

Bozidar Savic ◽

Ivan Stancic ◽

...

Keyword(s):

Blood Serum ◽

Porcine Circovirus Type ◽

Elisa Test ◽

Porcine Circovirus Type 2 ◽

Porcine Circovirus ◽

Sudden Increase ◽

Data Points ◽

Antibody Titers ◽

Fattening Pigs

Infection of pigs caused by porcine circovirus type 2 (PCV2) is present throughout the world. The aim of this study was to determine, based on the follow-up of the class IgG titers in piglets and fattening pigs, the duration of colostral immunity against infections in pigs caused by PCV2. The study included 28 piglets, whose titer was determined by using indirect ELISA test in intervals up to 110 days of age. The observed average values of IgG in piglets aged 21 days (8.47 log2) and 35 days (6.69 log2) in our surveys indicate very high titers of maternal antibodies, and that the piglets at this age are, to some extent, protected from infection caused by PCV2. Absence of the specific anti PCV2 antibodies was determined in 14.29% (21 days old) and 15.38% (35 days old) piglets at this age. The average titer of antibodies, specific for PCV2, in blood serum of piglets on the 50th day decreased to 3.74 log2, what indicates that in the majority of piglets (61.54%) catabolism of colostral antibodies occurred. On the 80th day of the piglets life there were no seropositive specimens, which unambiguously indicates that in this age, there was a complete catabolism of colostral antibodies and the disappearance of passive immunity. In all the 110 days? old fattening pigs, an average antibody titer recorded a sharp rise (12.78 log2). Possible reasons for this sudden increase in PCV2 antibody titers in the blood serum of fattening pigs is is a widespread presence of this infection in our region, as well as the fact that there exists a part of pigs population which is not immune to PCV2 infection. The results of this research are important for choosing the optimal moment for vaccination, considering that high titers of colostral antibodies of class G on the 21st and 35th day of piglets? life have been proven. This data points out to a possible interference with vaccine immunogens in the case of vaccination in this particular age.

Download Full-text

Comparison of porcine circovirus type 2 (PCV2)-associated lesions produced by co-infection between two genotypes of PCV2 and two genotypes of porcine reproductive and respiratory syndrome virus

Journal of General Virology ◽

10.1099/vir.0.066290-0 ◽

2014 ◽

Vol 95 (11) ◽

pp. 2486-2494 ◽

Cited By ~ 8

Author(s):

Changhoon Park ◽

Hwi Won Seo ◽

Su-Jin Park ◽

Kiwon Han ◽

Chanhee Chae

Keyword(s):

Porcine Circovirus Type ◽

Porcine Circovirus Type 2 ◽

Daily Weight Gain ◽

Porcine Circovirus ◽

Respiratory Syndrome Virus ◽

Associated Lesions ◽

Significant Difference ◽

Concurrent Infections

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.

Download Full-text