SEROPREVALENCIJA TE ODREĐIVANJE ANTIGENSKIH I GENSKIH OBILJEŽJA VIRUSA INFLUENCE SVINJA U REPUBLICI HRVATSKOJ

doctoral thesis

• Title (english): SEROPREVALENCE, ANTIGENIC AND GENETIC CHARACTERIZATION OF SWINE INFLUENZA VIRUS IN CROATIA
• Author: Andreja Jungić
• Mentor: Vladimir Savić (mentor)
• Mentor: Josip Madić (komentor)
• Committee member: Ljubo Barbić (predsjednik povjerenstva)
• Committee member: Vladimir Stevanović (član povjerenstva)
• Committee member: Lorena Jemeršić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Veterinary Medicine; (Department of Microbiology and Infectious Diseases with Clinic); Zagreb
• Defense date and country: 2021-02-17, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Veterinary Medicine; Veterinary Public Health and Food Safety
• Universal decimal classification (UDC): 636.09 - Veterinary science

Abstract

Virus influence tipa A vaţan je uzročnik dišnih bolesti kojim se mogu zaraziti različite vrste ţivotinja. Infekcija virusom influence u svinja javlja se u obliku enzootija svugdje u svijetu čineći pri tome ekonomske gubitke. Glavna osobina virusa influence tipa A je njihova sposobnost mijenjanja antigenske strukture što posljedično uzrokuje stvaranje novih podtipova virusa. Svinja moţe istovremeno biti inficirana i virusima influence ptica i ljudi te je idealan medij za preslagivanje gena, a virusne presloţenice koje pri tom nastaju mogu probiti barijeru vrste. S ciljem odreĎivanja seroprevalencije u RH, imunoenzimnim testom za dokazivanje protutijela za nukleoprotein (NP) virusa influence svinja pretraţeno je 1536 uzoraka krvnog seruma svinja, a protutijela za NP virusa influence svinja utvrĎena su u 466 (30,3 %) uzoraka. Postupkom inhibicije hemaglutinacije (IHA) utvrĎeno je da je najzastupljeniji podtip u uzgojima bio H1N1 (44,6%), zatim slijedi H3N2 (42,7%) i H1N2 (26,3%), a u 62,19% uzoraka krvnog seruma svinja utvrĎena su protutijela za barem jedan podtip. Imunohistokemijskom metodom pretraţeno je 28 uzoraka tkiva pluća na prisutnost VIS od kojih je u 8 utvrĎen antigen VIS. Lančanom reakcijom polimerazom u stvarnom vremenu (RT PCR) od 142 pretraţena uzorka plućnog tkiva, gen M bio dokazan u 9 uzoraka. Gen M VIS takoĎer je bio dokazan u 7 od 29 ukupno pretraţenih nazofaringealnih obrisaka. Metodom RT-PCR dokazali smo ciljane odsječke gena HA i NA u 6 uzoraka pluća i 3 uzorka nazofaringealnih obrisaka. Rezultati prikazani ovom disertacijom upotpunili su prve spoznaje o prisutnosti virusa influence svinja u Republici Hrvatskoj.

Abstract (english)

INTRODUCTION Swine influenza (SI) is an important viral disease caused by influenza A viruses that belong to the family Orthomyxoviridae. Influenza A viruses (IAV) are characterised by subtype of the two major surface glycoproteins, haemagglutinin and neuraminidase. The natural reservoir for IAVs are waterfowls, but both human and swine are also considered as its hosts. Swine has been considered as a „mixing vessel“ of new IAVs because of its susceptibility to infection with IAVs of different host origin. This doctoral thesis reports on a serological and virological survey for swine influenza virus (SIV) in pig population in Croatia. METHODS A total of 1536 blood sera samples were investigated for presence of SIV antibodies and 410 sera samples were examined for presence of HA antibodies by haemagglutination inhibition (HI) assay. 142 lung samples and 29 nasal swabs were investigated by molecular methods of SIV detection, with generic primers capable of detecting M gene which is common to all influenza A viruses. Due to subtyping od SIV, amplification of HA and NA gene fragments was performed and phylogenetic analysis was done. Detection of SIV antigen was made by IHC in lung samples collected post mortem. RESULTS In total of 1536 examined blood sera samples by ELISA, antibodies for SIV nucleoprotein (NP) were detected in 466 (30.3%). Results made by HI indicate that the most common subtype of SIV in Croatian pig population was H1N1 (44.6%), followed by H3N2 (42.7%) and H1N2 (26.3%). Antibodies against at least one subtype were detected in 62.19% of the blood sera samples. SIV antigen was detected in 8 of 28 lung tissue samples. M gene was detected in 9 of 142 lung tissue samples and in 7 of 29 nasopharyngeal swab samples. Phylogenetic analysis of amplified HA and NA gene fragments in 9 Croatian isolates indicates the presence of subtype H1N1 virus of wholly avian origin.
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CONCLUSIONS
Different H1N1, H1N2 and H3N2 swine influenza viruses circulate in Europe. Some of those
viruses are widespread but there is also a regional variability. There results demonstrated that
subtypes H1N1, H1N1 and H3N2 are circulating in pig population in Croatia. Pandemic strain
H1N1pdm which is circulating in some European countries is still not detected in Croatia. The
continuous monitoring, surveillance and molecular characterization of the circulating SIVs is of
major concern. Understanding the role of swine in spreading of these circulating viruses is necessary.

• Keywords: Ključne riječi: virus influence svinja; svinje; seroprevalencija; imunohistokemija; genska raznolikost; Hrvatska
• Keywords (english): Rad ne sadrži ključne riječi na drugom jeziku.
• Language: croatian
• URN:NBN: urn:nbn:hr:178:057518
• Promotion: 2018
• Study programme: Title: integrated undergraduate and graduate university study of veterinary medicine; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica veterinarske medicine (doktor/doktorica veterinarske medicine)
• Type of resource: Text
• Extent: 122 str.
• File origin: Born digital
• Access conditions: Open access
• Created on: 2021-02-17 10:30:45