Development and validation of a recombinant nucleocapsid protein-based ELISA for detection of the antibody to porcine reproductive and respiratory syndrome virus

Abstract

Three indirect enzyme-linked immunosorbent assays (iELISA) based on the North American like (NA-like), European like (EU-like) and co-expressed NA- and EU-like recombinant nucleocapsid proteins (N-protein) of porcine reproductive and respiratory syndrome virus (PRRSV) were validated for the detection of the antibodies in porcine sera. A total of 422 serum samples from unvaccinated pigs were tested. The cut-off value was optimized by a two-graph receiver operating characteristics analysis at a 95% confidence level. This assay was validated with Western blot analysis and IDEXX HerdChek ELISA. Cross-reactivity results showed that iELISA was PRRSV-specific. Repeatability tests revealed that the coefficients of variation of positive sera within and between runs were less than 10%. The results indicate that iELISA is simpler to produce and perform, time-saving and suitable for large scale surveys of PRRSV infection at low cost, and is potentially useful to evaluate the efficiency of various vaccines against PRRSV.

Performance of ELISAs for detection of antibodies against porcine respiratory and reproductive syndrome virus in serum of pigs after PRRSV type 2 live vaccination and challenge

“…The specificity of the QIAGEN ELISA was, at 98.1 %, lower than the IDEXX which had a 100 % specificity as has been published previously [5, 7, 12], respectively a 99.9 % specificity, according to the manufacturer. The specificity of the INgezim ELISA was with 99.0 % between these two ELISAs [12].…”

“…In a recently published study, the sensitivity of the IDEXX ELISA was stated at 80 % in the field samples tested, compared to the immunoperoxidase monolayer assay (IPMA) [15]. This is in contrast to other studies which stated a sensitivity of the IDEXX ELISA of 100 % in serum samples 21 days after PRRSV inoculation [5] and of 91.5 % in field samples [7]. …”

“…In addition to the cost-effective, simple and rapid analysis by ELISA, alternative methods, such as serum neutralization test, immunofluorescence assay or Western blot are used for special indications [3, 5–7]. In recent years, several ELISAs for detection of Ab against PRRSV in pig serum have been developed [7–9], some of them with the intention of making them commercially available. Some ELISAs, however, have been on the market for many years and have been continuously adapted and improved.…”

“…Most of the ELISAs are able to detect Ab against PRRSV type 1 and type 2 [14]. However, some have been described as able to distinguish between PRRSV types [5, 7, 13]. The ELISAs presently used in routine analysis are usually based on the PRRSV nucleocapsid protein as antigen [15].…”

Development of an indirect enzyme-linked immunosorbent assay (ELISA) assay based on a recombinant truncated VP2 (tVP2) protein for the detection of canine parvovirus antibodies

“…In addition, the purification of the virion is laborious and expensive. Therefore, many researchers choose the recombinant protein, which has advantages over the whole virion as an antigen for the detection of antibodies (Ko et al, 2009;Chu et al, 2009). Firstly, the recombinant protein antigen is not infectious, so one can use the CPV serodiagnostic assay rapidly and safely, without the use of special virus-treated facilities.…”