Vol 62, No 3 (2017)

Serologic studies occupy a significant place in influenza diagnosis. The article presents an analysis of the developed experimental version of ELISA test-systems for the detection of specific antibodies to the virus influenza A(H1N1)pdm09, and their dynamics at different stages of infection as compared with those of the traditional HAI method. The study included 20 paired samples of serum from patients hospitalized at different stages of the disease with etiology associated with the influenza virus A(H1N1)pdm09. Two groups were formed on the basis of HAI data, which showed the presence or absence of significant growth of specific antibodies to the influenza virus A(H1N1)pdm09. The control group consisted of 20 serum samples from individuals without influenza but with chronic hepatitis C. To examine the virus specific antibody two types of ELISA test systems were used. The first system was intended for the detection of IgM to the influenza virus A(H1N1)pdm09; the second was used for revealing specific IgG. The study showed the accuracy and specificity of detectable IgM and IgG to the virus influenza A(H1N1)pdm09. The dynamics of specific IgG titers in 15 of the 20 pairs of sera was reliable. The increase in titers was more pronounced than in the HAI. IgM against influenza virus could be detected up to 10 days, although reliable dynamics of these antibodies was not detected in paired samples. The test system was specific for the determination of both IgG and IgM antibodies to the influenza virus A(H1N1)pdm09 and significantly more sensitive than HAI. Using this ELISA test system, it is possible to monitor the dynamics of IgG to this virus even in the absence of diagnostic increases in antibody titers in HAI.

Background. In terms of serological properties and immunization, the wild type of HBsAg HBV and its G145R mutant behave as different antigens. This testifies to serious structural changes, which presumably could have a significant impact on the morphogenesis of virions and subviral particles. Nevertheless, morphological and ultrastructural investigations of HBV with G145R mutation have not been carried yet. Objectives. Research of structural and morphological organization of HBV in the presence of the G145R escape mutation. Methods. Studies of sera, purified viruses and recombinant HBsAg were carried out by transmission electron microscopy by the method of negative staining and indirect reaction of immunelabeling using monoclonal antibodies of different specificity. Specimens of wild type HBV and HBV with S143L mutation obtained in an identical manner were used as the control. Results. The presence of typical virus particles of HBV was shown in the specimens of wild strain and HBV with S143L mutation. Specimens of HBV with G145R mutation were characterized by expressed morphological heterogeneity. In the initial serum and in the specimen of purified virus containing G145R mutant, large oval particles 60-70 nm and up to 200 nm in size, respectively, were found. The presence of antigen structures of HBV in all heterogeneous forms was confirmed. It was shown that forming of subviral particles in the process of expression of the recombinant HBsAg with G145R mutation depends on conditions of expression and purification of the protein. They can vary from well-formed circular and oval particles to practically unstructured fine-grained masses. Conclusion. Direct data on the impact of G145R escape-mutation in S-gene, in contrast to S143L mutation, on the morphogenesis of virions and subviral particles of HBV were obtained.

Helicoverpa zea (Boddie, 1850) (Hz) single nucleocapcide nucleopolyhedrovirus (SNPV) was adapted to the cotton bollworm (Helicoverpa armigera, (Hübner, 1805) (Ha)) by five blind passages on larvae. The full genomic sequence of the resulting strain HS-18 has been determined (GenBank acc. №: KJ004000.1). Biological activity of the HS-18 strain is higher than the activity of all other Russian strains of NPV, as far as cotton bollworm strain HearSNPV-G4. HS-18-infected caterpillars at the 3-rd and 4-th ages died much faster than those infected with HearSNPV-G4 strain. A major difference of HS-18 genome is an 18 bp repeat in the RING-finger ORF that confirms high variability of this region. Three other insertions and seven base substitutions were observed earlier, while six base substitutions are new. Mutations are located at ORF42, lef-9, ORF58, VP39, PIF-4, P48, SOD, ORF111, ORF129 and ORF138 genes. Among all nucleotide mutation only one is synonymous. Thus we suppose the selective pressure to the virus. The resulting strain HS-18 is recommended as a biopesticide for controlling the number of cotton bollworm in cotton fields.

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