Detection of porcine circovirus genotypes 2a and 2b in aborted foetuses from infected swine herds in the State of São Paulo, Brazil

Abstract

BackgroundPorcine circovirus type 2 (PCV2) has been associated with several disease complexes, including reproductive failure. The aim of this study was to identify the subtypes of PCV2 that are associated with reproductive failure in pigs from the State of São Paulo, Brazil and to investigate co-infections with other infectious organisms.FindingsSamples of 168 aborted foetuses or mummified foetuses from five farrow-to-finish swine farms known to be infected with PCV2 and located in the State of São Paulo were tested for PCV2 by polymerase chain reaction (PCR). Positive samples were additionally tested for porcine parvovirus (PPV), Leptospira spp. and Brucella spp. by PCR. PCV2 was detected in 18 of the samples (10.7%). PPV, Brucella spp. and Leptospira spp were found in 2, 10 and 0 cases, respectively. Eleven PCV2 strains were sequenced and determined to be either genotype 2a (n = 1) or 2b (n = 10).ConclusionsThe findings indicate that the frequency of PCV2 infections in aborted porcine foetuses from the State of São Paulo is rather low (10.7%) and that co-infection with other pathogens is common and may be involved in PCV2 associated reproductive failure. No repeatable, characteristic amino acid motifs for regions of the PCV2 capsid protein seemed to be associated with abortion in sows.

Vertical Transmission of PCV2b to Fetuses in Sows Intramuscularly Infected with PCV2b

“…Likewise, PCV2 transmission through sows' placenta using PCV2 intrauterinely injected into pregnant sows was also reported in previous study (Yoon et al 2004). Furthermore, transplacental infection by PCV2 under field condition was proved by another study (de Castro et al 2012). Vertical transmission of PCV2b in female Kunming mice was confirmed in our previous studies by 2 different ways (Deng et al 2013a(Deng et al , 2013a.…”

“…Vertical transmission of PCV2 in sows under field conditions was proved by de Castro et al (2012), the results showed that in PCV2-infected sows (even in healthy), a high prevalence of PCV2 viremia could be detected in their pre-suckle piglets. Transplacental infection by PCV2 under experimental conditions was reported in previous studies (Pensaert et al 2004, Sarli et al 2012.…”

Dynamics of porcine circovirus type 2 infection and neutralizing antibodies in subclinically infected gilts, and the effect on their litters

“…Similarly, this study revealed PCV2 subclinical infection with both genotypes in gilts from commercial and multiplier herds. The results of this research are consistent with previous field and experimental reports, in which both genotypes have been detected in PCV2 infection in utero (Lefebvre et al ., 2008;Castro et al ., 2012). Furthermore, gross lesions of PCV2 fetal infection and high PCV2 titers in tissues were noted across all PCV2 isolates used in experimental studies (Larochelle et al ., 2000).…”

“…Furthermore, gross lesions of PCV2 fetal infection and high PCV2 titers in tissues were noted across all PCV2 isolates used in experimental studies (Larochelle et al ., 2000). In addition, with the information known to date, it appears that genotype differences between PCV2 isolates cannot account for the reproductive manifestations of the virus and no repeatable characteristic amino acid motifs in the PCV2 capsid protein or in the residues used for genotype classification were associated with reproductive failure (Castro et al ., 2012).…”

“…The experimental intrauterine infection with PCV2 resulted in virus replication in the fetuses (Sánchez et al ., 2001;Madson et al ., 2009a;Saha et al ., 2010), reproductive disease associated with fetal pathology (Johnson et al ., 2002) and early embryonic death during intrauterine PCV2 infection (Mateusen et al ., 2007). Other case reports of reproductive failure implicated PCV2 either as the sole agent or in conjunction with other reproductive disease agents (Brunborg et al ., 2007;Castro et al ., 2012).…”