Filogenetska analiza VP2 gena parvovirusa pasa u Republici Hrvatskoj

master's thesis

• Title (english): Phylogenetic Analysis of Canine Parvovirus - 2 VP2 Gene in Dogs in Croatia
• Author: Ana Miljan
• Mentor: Suzana Hađina (mentor)
• Mentor: Vladimir Stevanović (mentor)
• Committee member: Zoran Milas (predsjednik povjerenstva)
• Committee member: Josip Madić (član povjerenstva)
• Committee member: Suzana Hađina (član povjerenstva)
• Granter: University of Zagreb; Faculty of Veterinary Medicine; (Department of Microbiology and Infectious Diseases with Clinic); Zagreb
• Defense date and country: 2017-07-07, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Veterinary Medicine

Abstract

U razdoblju od 1. lipnja 2015. do 31. ožujka 2017. godine iz veterinarskih organizacija s područja grada Zagreba ukupno je prikupljeno i obrađeno 747 uzoraka fecesa i obrisaka rektuma pasa koji su pokazivali znakove akutnog gastroenteritisa. Osim uzoraka fecesa za 228 pasa, prikupljeni su i podaci o nacionalu, anamnezi, kliničkoj slici, tijeku i ishodu liječenja. Metodom lančane reakcije polimeraze u uzorcima fecesa ili obriscima rektuma dokazivana je prisutnost psećeg parvovirusa-2.
Na osnovu rezultata pretrage uzoraka ustanovljeno je da je parvovirusna infekcija pasa najznačajniji pojedinačni uzrok akutnog gastroenteritisa pasa na području grada Zagreba s prevalencijom od 47,37% u populaciji bolesnih pasa. Nakon određivanja nukleotidnog slijeda umnoženih odsječaka virusnog genoma ustanovljena je prisutnost sva tri poznata podtipa CPV-2 virusa, a najzastupljeniji su podtipovi CPV-2c (59%) i CPV-2a (23%). Dokazane su i aminokiselinske izmjene u kapsidi terenskih sojeva CPV-2 na mjestima 297 i 373 koje su ustaljene, a mogu utjecati na izbjegavanje imunosnog odgovora domaćina.
Iz dodatnih podataka prikupljenih za statističku obradu bilo je vidljivo da način držanja uvjetuje razlike u zastupljenosti pojedinih podtipova virusa i riziku od oboljenja koji je značajno viši u populaciji napuštenih pasa. Najveća učestalost oboljenja od parvovirusne infekcije pasa je bila u prvoj godini života, s nešto smanjenim rizikom u dobi od četiri do šest mjeseci, ali je isto tako pokazano da imunoprofilaksa smanjuje rizik od infekcije CPV-2, neovisno o cijepnom i infektivnom podtipu virusa. Ovo istraživanje je također omogućilo kritičku prosudbu rezultata brzih imunokromatografskih testova za koje je ustanovljeno da imaju izrazito nisku osjetljivost u kliničkim uvjetima izvođenja.
Zaključno, određivanje podtipa infektivnog virusa nema klinički značaj, ali je izrazito bitno za praćenje epizootiologije bolesti. Isto tako, ovo istraživanje ukazalo je na ograničenja klasične metode lančane reakcije polimerazom te naglasilo potrebu za uvođenjem novih metoda dijagnostike koje bi omogućile razlikovanje cijepnog od terenskih sojeva.

Abstract (english)

A total of 747 faecal samples or rectal swabs from dogs with clinical signs of acute gastroenteritis were collected between June 1st 2015 and March 31st 2017. Samples were obtained from veterinary organisations in the city of Zagreb area. Information about signalment, medical history, course and outcome of the treatment for 228 dogs were collected as well. All collected samples were tested for presence of canine parvovirus-2 (CPV-2) using polymerase chain reaction (PCR). The prevalence of 47.3% in the sick canine population makes CPV-2 the most significant single cause of acute gastroenteritis in dogs in the city of Zagreb area. Products of PCR reaction were sequenced and obtained nucleotide sequences confirmed the presence of all three CPV-2 subtypes. Subtype CPV-2c and CPV-2a were detected in 59% and 23% infected dogs, respectively. Additionally consistent amino acid substitutions have been demonstrated at site 297 and 373 in the viral capsid, which comprise immunogenic sites and may affect host immune response.
Statistical analysis revealed dog housing as important factor influencing CPV-2 subtype distribution and risk of acquiring CPV-2 infections. The highest incidence of parvovirus infection was detected during the first year of life, with a slightly lower risk between four to six months of age. This study showed that animals with history of vaccination were under lower risk of CPV-2 infection, regardless of the infectious viral subtype. In addition, results of statistical analysis showed extremely low sensitivity of rapid immunochromatographic tests results in the clinical setting.
To conclude, the determination of the infectious CPV-2 subtype has no clinical relevance, but gives extremely valuable data for surveillance of canine parvovirus enteritis. This study pointed out the limitations of classical polymerase chain reaction method and the need for introduction of new diagnostic that could distinguish field strains from vaccine strains

• Keywords: analiza; parvovirus; pas
• Keywords (english): analysis; parvovirus; dog
• Language: croatian
• URN:NBN: urn:nbn:hr:178:364835
• Study programme: Title: Veterinary Medicine; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: doktor/doktorica veterinarske medicine (doktor/doktorica veterinarske medicine)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2018-07-23 09:29:14