Projects / Programmes
Molecular and immunologic analyses of Slovene isolates of avian influenza virus H5N1
| Code |
Science |
Field |
Subfield |
| 4.04.00 |
Biotechnical sciences |
Veterinarian medicine |
|
| Code |
Science |
Field |
| B750 |
Biomedical sciences |
Veterinary medicine: surgery, physiology, pathology, clinical studies |
Birds, poultry,avian influenza virus, H5N1, immunology, virology
Researchers (11)
Organisations (2)
Abstract
Ongoing outbreaks of H5N1 avian influenza (AI) in migratory birds, waterfowl, domestic poultry and also in mammals present a continuing treat in the fields of animal and human health. The increasing relevance of AI has highlighted the lack of scientific information on several aspects of the disease.
The ability of AI virus (AIV) to cause a disease and ability of the host to respond to infection varies greatly by species. Prior to ongoing H5N1 epizootic highly pathogenic AI (HPAI) had only once affected wild birds significantly. It appeared that HPAI was a disease of domestic birds and that the wild birds usually harbored only the low pathogenic form of the disease. Very little is known about the viral and host factors that determine the species range of influenza viruses or about the mechanisms by which host barriers are crossed. The aim of our study is to fully characterize the surface viral proteins haemagglutin (HA) and neuraminidase (N) and matrix 1 (M1) protein of recent Slovene isolates of AIV H5N1 and to compare molecular characteristics of isolates from different bird species. With the cloning of the HA gene we shall prepare recombinant HA protein, which will serve for the production of specific antibodies as well as antigens for serological tests.
In addition. The ability of AIV isolates from different species of birds to replicate in different cells cultures and cell lines of avian and mammalian origin will be compared and molecular changes occurring in the sequence of HA, N and M1 of replicating AIV will be determine.
Significance for science
Highly pathogenic avian influenza (AI) was one of the first viral diseases described in poultry. Ongoing outbreaks of H5N1 AI in migratory waterfowl, domestic poultry and also in mammals present a continuing treat in the fields of animal and human health. The increasing relevance of AI has highlighted the lack of scientific information on several aspects of the disease.
Very little is known about the viral and host factors that determine the species range of influenza viruses. The molecular characterization of the important viral proteins of the recent Slovene isolates was studied. Viruses identified in Slovenia showed close relationship with H5N1 viruses from other European countries (EMA clade 1) Comparison of nucleotide sequences of hemagglutinin gene obtained for H5N1 isolates from different bird species indicated that two different HPAI H5N1 viruses were introduced in Slovenia in 2006, despite relatively short duration of HPAI outbreak.
We compared the ability of HPAI isolate H5N1 of avian origin to adopt and grow on different cells cultures of avian and mammalian origin. We analyzed also potential molecular changes on main antigenic determinates such as hemagglutinin gene. The growth of the virus was estimated by determination of genome copies by real time RT-PCR and determination of cythopatic effect (CPE). The results confirmed that passages on embryonated eggs lead to mutation in hemagglutinin gene, meanwhile no mutations were observed after passages on cell cultures.
The new serological methods will allow further studies on immunologic response of different species of birds against different pathogens, including AIV of particular subtype e.g.H5N1. We were able to produce and characterise monoclonal antibodies specific for various epitopes of HPAI H5N1 isolate from Slovenia.
It also could be expected that data from the study of the interaction between Mycoplasma species provide an insights into mechanisms leading to the increased pathogenicity in such concomitant infections.
Significance for the country
This study is relevant to the situation that occurred in Slovenia (and also elsewhere) in the spring 2006. A fear of transmission of AIV H5N1 to the domestic poultry and particularly to human population was obvious. This clearly requires further investigations concerning the AIV that have been isolated from wild birds in Slovenia, as well as further studies concerning the ability of H5N1 to infect and replicate in different types of cells. We are convinced that results of this research project would be very valuable, particularly in the case that new treat of AIV and potentional pandemic situation will occur again.
The infection with AIV represent a considerable danger also to a number of free-living birds which represent a valuable part of the natural population in Slovenia. Results of our research project provide several data that enable better understanding of their infection with AIV. We improved diagnostics tests for more rapid and accurate detection of the AIV infection.
Most important scientific results
Annual report
2008,
2009,
final report,
complete report on dLib.si
Most important socioeconomically and culturally relevant results
Annual report
2008,
2009,
final report,
complete report on dLib.si
