ELISA test metapneumoviral infection of bird: methodology of development and use in veterinary practice

Abstract
In the absence of diagnostic kits for the detection of antibodies to metapneumovirus infection (MPVI) epizootological monitoring in Ukrainian farms is practically not carried out, imported test systems have a "sky-high" price, so there is a need for domestic methods of diagnosing this disease. The most accurate, easy-to-use method is ELISA-based test systems (enzyme-linked immunosorbent assay). A diagnostic ELISA test system for the detection of antibodies to MPVI has been developed and it has been established that this diagnosticum should be used in the practice of veterinary medicine for serological control of metaviral virus infection. The optimal ratios of components for the manufacture of ELISA test system have been worked out. The form of calculation of antibody titers in blood sera of chickens when testing them in one dilution is calculated. The sensitivity and specificity of the ELISA test system were determined (comparative analysis of serum testing results in ELISA, RNGA and RN). Scientific documentation has been developed – instructions for the manufacture and control of ELISA test systems for the detection of antibodies to metapneumovirus infection in the serum of chickens and instructions for its use. Indication and identification of the obtained virus isolate was carried out using polymerase chain reaction (PCR) and nucleotide sequencing. Based on the studies carried out in the suspension of the internal organs of turkeys (trachea, lungs), a virus belonging to subtype B of the genus Metapneumovirus, subfamily Pneumovirinae, family Paramyxoviridae of the order Mononegavirales was revealed. By comparing the nucleotide sequence of the G gene fragment of the PVT-09/B strain with the sequences of strains and isolates of the avian metapneumovirus subtype B published in the GenBank database, it was found that the metapneumovirus isolated from sick turkeys is phylogenetically close to the Brazilian strains 27A-07 2007 and MPV/B/Brazil-07/USP-08 G