Bulletin "Veterinary biotechnology"

Veterynarna biotehnologija – Veterinary biotechnology, 2018, 32, 383-390 [in Ukrainian]. https://doi.org/10.31073/vet_biotech32(2)-47

MUZYKA D., email: This email address is being protected from spambots. You need JavaScript enabled to view it., STEGNIY B., email: This email address is being protected from spambots. You need JavaScript enabled to view it., RULA O., This email address is being protected from spambots. You need JavaScript enabled to view it., TKACHENKO S., email: This email address is being protected from spambots. You need JavaScript enabled to view it.

National Scientific Center "Institute of Experimental and Clinical Veterinary Medicine"

PISHCHANSKYI O.V., email: This email address is being protected from spambots. You need JavaScript enabled to view it.

State Research Institute of Laboratory Diagnostics and Veterinary and Sanitary Expertise

NAPNENKO O., email: This email address is being protected from spambots. You need JavaScript enabled to view it.

State Scientific-Control Institute of Biotechnology and Strains of Microorganisms

BIOLOGICAL PROPERTIES OF LOW PATHOGENIC AVIAN INFLUENZA VIRUS H7N3 ISOLATED FROM WILD DUCKS

Introduction. To date, the influenza virus remains an unpredictable infection for animals, birds and humans. The emergence of new strains and variants with new properties and pathogenicity to new hosts requires constant observation and thorough investigation of new viruses. Some highly pathogenic and low pathogenic avian influenza viruses of H5 and H7 subtypes, characterized by high genetic variability, are concern to the national community as they rapidly mutated, capable of overcoming the interspecific barrier and infecting other animals, including humans.

The goal of the work was to study the biological properties of a low-pathogenic avian influenza virus with 7 subtypes of hemagglutinin isolated from wild ducks, to establish the prospects of its further use as a production strain for the production of veterinary immunobiological preparations.

Materials and methods. The study was carried out using the avian influenza virus A/Mallard/AN/23-15-02/2011, isolated from wild ducks. All work with the pathogen was conducted in special conditions, which excluded the pathogen exposure to the environment. The cultivation of the virus, the determination of the biological and lethal activity of the virus (based on Reid and Mench method) was carried out using chicken embryos at the age of 9-11 days in accordance with the recommendations of the International Office of Epizootics (OIE). The hemagglutinum activity of the virus was determined in the hemagglutination inhibition test with a 1% suspension of red blood cells of the rooster according to the generally accepted method recommended by the FEM. The identification of the virus was carried out using the reference serum antibodies to the influenza A virus subtypes H1-H16 and avian paramyxoviruses PMV1-PMB4 and PMV6-PMV9 produced by the OIE/FAO Reference Laboratory for Newcastle disease and Avian Influenza, the Institutto Zooprofillatico delle Venezie (Italy) and the Veterinary Laboratories Agency (UK).

Results of research and discussion. The results of studies of the biological properties of the bird flu virus subtype H7N3, isolated from wild waterfowl wild ducks in 2011, presented in the title. The ability of the virus to produce specific antibodies was established when the inactivated antigen was administered to experimental chickens in a mixture with the adjuvant "Montanide ISA-70" in the ratio 1:1 in titer (4.7±1.3) log2. The results of the study of infectious and lethal activity of the indicated antigen are also 7.5 lg ЕІD50/0,2cm3 and 1.5 lg ЕLD 50/0.2cm3. According to the results of the sequencing of the EIPKGR/GLE haemagglutinin cutting site, this isolate is classified as a group of low pathogenic ones. Based on the data obtained, a Declaration patent for this strain was received and it was proposed for further use for vaccine production and diagnostic test kits creation. The further conduct of epizootic surveillance activity of the circulation of the influenza virus among waterfowl and synanthropic birds was substantiated.

Conclusions and prospects for further research. The conducted studies proved the belonging of the influenza virus to low-pathogenic variants and the possibility of its use as a component of diagnostic test kits has been proved.

Keywords: low pathogenic avian influenza, wild birds, epizootologic monitoring.

REFERENCES

  1. Cilloni, F., Toffan, A., Giannecchini, S., Clausi, V., Azzi, A., Capua, I. et al. (2010). Increased pathogenicity and shedding in chickens of a wild bird-origin low pathogenicity Avian influenza virus of the H7N3 subtype following multiple in vivo passages in quail and turkey. Avian Diseases, 54(s1), 555-557.
  2. Arnold, E., Slomka, M.J., Breed, A.C., Hjulsager, C.K., Pritz-Verschuren S., Venema-Kemper, S. et al. (2018). Evaluation of ELISA and haemagglutination inhibition as screening tests in serosurveillance for H5/H7 avian influenza in commercial chicken flocks. Epidemiol Infect., 146(S3), 306-313.
  3. Hu, Z., Jiao, X., Liu, X. (2017). Antibody Immunity Induced by H7N9 Avian Influenza Vaccines: Evaluation Criteria, Affecting Factors, and Implications for Rational Vaccine Design. Front Microbiol., 26(8), 1898.
  4. Abdelwhab, E. M., Veits, J., Mettenleiter, T. C. (2014). Prevalence and control of H7 avian influenza viruses in birds and humans. Epidemiol Infect., 142(5), 896-920.
  5. Office International des Épizooties (Ed.). (2008). Manual of diagnostic tests and vaccines for terrestrial animals (mammals, birds and bees) (6th ed., Vols. 1–2). Paris: OIE.
  6. Dufour-Zavala, L., American Association of Avian Pathologists (Ed.). (2008). A laboratory manual for the isolation, identification, and characterization of avian pathogens (5th ed.). Athens, GA: American Association of Avian Pathologists.

Download full text in PDF