[The rapid ELISA method for detection of orthopoxviruses].

INTRODUCTION: Following the successful eradication of smallpox, mass vaccination against this disease was discontinued in 1980. The unvaccinated population continues to be at risk of infection due to military use of variola virus or exposure to monkeypox virus in Africa and non-endemic areas. In cases of these diseases, rapid diagnosis is of great importance, since the promptness and effectiveness of therapeutic and quarantine measures depend on it. The aim of work is to develop a kit of reagents for enzyme-linked immunosorbent assay (ELISA) for fast and highly sensitive detection of orthopoxviruses (OPV) in clinical samples. MATERIALS AND METHODS: The efficiency of virus detection was evaluated by single-stage ELISA in the cryolisate of CV-1 cell culture samples infected with vaccinia, cowpox, rabbitpox, and ectromelia viruses, as well as in clinical samples of infected rabbits and mice. RESULTS: The method of rapid ELISA was shown to allow the detection of OPV in crude viral samples in the range of 5.0 1025.0 103 PFU/ml, and in clinical samples with a viral load exceeding 5 103 PFU/ml. CONCLUSIONS: The assay involves a minimum number of operations and can be performed within 45 minutes, which makes it possible to use it in conditions of a high level of biosecurity. Rapid ELISA method was developed using polyclonal antibodies, which significantly simplifies and reduces the cost of manufacturing a diagnostic system.

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

INTRODUCTION: 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. OBJECTIVES: Development of a sensitive, fast and easy-to-use immunochemical test for the detection of orthopoxviruses in the «point of care¼ format. MATERIAL AND METHODS: 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. RESULTS AND DISCUSSION: 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. CONCLUSION: 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.

[The selection of system of detection for multiplex dot-immune analysis of antibodies].

The comparative evaluation was carried out concerning systems of detection using conjugates on the basis of peroxidase, alkaline phosphatase, colloid gold and system of amplification "Super-CARD" for multiplex dot-immune assay of antibodies. It is established that sensitivity of system of detection with colloid gold is approximately 8 times higher than with amplification "SuperCARD"; 30 times higher than with conjugate of alkaline phosphatase and 250 times higher than with peroxidase conjugate. The immunesols of gold maintain limit of detection of human IgG 10 pg with dynamic range of signal alteration from 5 ng to10 pg overlapping the range of concentrations of specific IgG in case of typical natural immune response. The most specific results provides conjugate of colloid gold with monoclonal antibodies to human IgG.

[The multiplex method of estimation of humoral immunity to vaccine regulated childhood infections].

The goal of this work was to present the results of the laboratory tests of the multiplex dot immunoassay method using protein microarray for complex estimation of humoral immunity to measles, mumps, and rubella viruses. It was shown that the obtained results were in a good agreement with data of commercial monospecific ELISA kits. The developed method is fast, requires fewer resources, and may be used in the field.