Application of pigeon circovirus recombinant capsid protein for detecting anti-PiCV antibodies in the sera of asymptomatic domestic pigeons and the potential use of a combination of serological and molecular tests for controlling circovirus infections in pigeon breeding flocks

Abstract

The aim of this study was to evaluate the serologic status of domestic pigeons not infected and asymptomatically infected with the pigeon circovirus (PiCV) with the use of an enzyme-linked assay based on PiCV recombinant capsid protein as a plate antigen. Recombinant PiCV capsid protein was produced by transforming E. coli BL21 (DE3) Rosetta colonies with expression plasmids.Blood samples and cloacal swabs were collected from 171 asymptomatic pigeons. The birds were divided into two groups (infected and not infected with PiCV) based on the results of Sybr Green real time PCR screening for the presence of PiCV genetic material. Approximately 70% of the pigeons tested positive for anti-PiCV antibodies regardless of their infection status. Antibody levels, the coefficient of variation and standard deviation were significantly higher in the group of infected pigeons.The results indicate that ELISA is a highly useful test that complements molecular methods in evaluations of PiCV infection status in domestic pigeons. The spread of pigeon circovirus infections can be controlled by keeping breeding flocks free of PiCV, which can only be achieved by subjecting birds to real time PCR and serological tests.

The epidemiology, molecular characterization and clinical pathology of circovirus infections in pigeons – current knowledge

“…Daum et al (2009) conducted a retrospective study of pigeon sera obtained in 1989, 1991 and 2008 and found anti-PiCV antibodies in 78% (61%-90%) of the tested samples on average. A recent serological study of Polish domestic pigeons from selected breeding flocks revealed the presence of anti-PiCV antibodies in 72% birds on average, regardless of their infection status (average prevalence of 36%) (Stenzel et al 2016). Somewhat different results were reported by who found anti-PiCV antibodies in 96% of the examined pigeons, but their study was performed on a very small population of 28 birds.…”

“…The prevalence of PiCV was determined by age and health status, and it was the highest (close to 100%) in young birds showing non-specific symptoms of the disease (Stenzel et al 2012). Asymptomatic infections were noted in 53% birds of all ages on average, and in 36% of adult domestic pigeons from breeding flocks (Stenzel & Pestka 2014;Stenzel et al 2014a;Stenzel et al 2016). Similar results were reported in studies of domestic pigeons conducted in Hungary (prevalence of less than 57%) and in China where PiCV DNA was isolated from 80.7% of diseased birds and 63.4% of asymptomatic birds (Zhang et al 2011;Cs agola et al 2012).…”

“…A specific protocol for the prevention of PiCV infections in pigeons has not yet been developed due to the absence of vaccines targeting this pathogen. In recent years, attempts have been made to develop a recombinant PiCV capsid protein for diagnostic tests and a subunit vaccine against the PiCV (Daum et al 2009;Lai et al 2014;Stenzel et al 2016). This vaccine could protect pigeons against PiCV infection and, possibly, lower the prevalence of YPDS.…”

“…Attempts have also been made to immunize parrots with the recombinant capsid protein of the psittacine circovirus, but the efficacy of the vaccine was not confirmed (Bonne et al 2009). In view of the above, the only available solution for controlling the spread of PiCV infections involves the prevention of common viral and bacterial diseases in pigeons, the use of immunomodulators during vaccination and weaning, elimination of stress, and selection of parent stock based on the results of serological and molecular tests (Duchatel & Szeleszczuk 2011;Stenzel et al 2011;Stenzel et al 2016). …”

Immunogenicity of Pigeon Circovirus Recombinant Capsid Protein in Pigeons

“…The prevalence of PiCV is determined by age and health status, and affects about 70% of the global pigeon population on average [ 5 , 6 , 7 ]. Asymptomatic infections with this virus are quite common and account for 36–53% of the population [ 8 , 9 , 10 ].…”