Rapid immunochemical method for the detection of orthopoxviruses (Orthopoxvirus, Chordopoxvirinae, Poxviridae).

Abstract

The abolition of smallpox vaccination has led to the disappearance of population immunity to pox viruses. However, the threat of infection by pathogenic orthopoxviruses persists and determines the need to develop sensitive and operational methods for indicating pathogens. Development of a sensitive, fast and easy-to-use immunochemical test for the detection of orthopoxviruses in the «point of care» format. We used preparations of cultural vaccinia virus (VV) with varying degrees of purification, polyclonal antibodies from hyperimmune rabbit serum, and equipment from a previously developed autonomous kit for dot-immunoassay on flat protein arrays. It has been established that rabbit polyclonal antibodies can be used in a single-stage dotanalysis, both as a capture agent immobilized on a substrate and as a detection reagent bound with colloidal gold particles. It is shown that the effectiveness of the detection of VV is inversely related to the degree of purification of viruses from sub-viral structures. The sensitivity of the rapid detection of viruses in a crude preparation was about 30 times higher than in pure viral material. The increase in sensitivity, presumably, occurs due to binding to the capture antibodies of subviral structures, which form large aggregates of sensitized gold particles. The test does not detect cross-reactions with heterogeneous viruses (measles, rubella and chickenpox) that cause exantematous diseases. The one-stage variant of the dot-immunoassay reduces the analysis time to 40 minutes and improves the detection sensitivity of orthopoxviruses in crude viral preparations to the range of 105-104 PFU / ml. Full makeup, ease of analysis and the ability to visually accounting for results allow the test to be used outside of laboratories.