Utvrđivanje proširenosti bakterije Francisella tularensis u populaciji mišolikih glodavaca

master's thesis

• Title (english): Prevalence of Francisella Tularensis in small Rodent Population
• Author: Mateja Vugrinec
• Mentor: Josipa Habuš (mentor)
• Committee member: Ljubo Barbić (predsjednik povjerenstva)
• Committee member: Suzana Hađina (član povjerenstva)
• Committee member: Josipa Habuš (član povjerenstva)
• Granter: University of Zagreb; Faculty of Veterinary Medicine; (Department of Microbiology and Infectious Diseases with Clinic); Zagreb
• Defense date and country: 2018-04-20, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Veterinary Medicine

Abstract

Tularemija je zoonoza koju uzrokuje gram negativna, kokobacilarna, nepokretna, aerobna bakterija Francisella tularensis. Glavni rezervoari bolesti su zečevi i glodavci, a najvažniji vektori su krpelji. Iako se bolest smatra endemskom, u posljednje vrijeme je u Europi zabilježena povećana pojavnost uz povremenu pojavu, najčešće manjih, zatvorenih epidemija. Uz ostale čimbenike, povećana incidencija bolesti veže se i uz klimatske promjene koje pogoduju širenju i povećanju brojnosti glodavaca (rezervoara) i krpelja (vektora). Cilj ovog istraživanja bio je utvrditi učestalost infekcije u mišolikih glodavaca i malih sisavaca unutar endemskih područja tularemije Republike Hrvatske. U tu svrhu ukupno 449 uzoraka jetre glodavaca pretraženo je pomoću lančane reakcije polimerazom u stvarnom vremenu kako bi se dokazalo prisustvo specifičnih odsječaka F. tularensis. Retrogradno su prikupljeni i analizirani i podaci o relativnoj gustoći populacije glodavaca tijekom izlova i zastupljenosti pojedenih vrsta. Dobiveni rezultati ukazuju da gustoća populacije glodavaca niti distribucija vrsta nije bila jednaka na svim područjima izlova. Fluktuacije u brojnosti zamijećene su i na istim lokacijama ovisno o datumu izlova. Prisustvo F. tularensis dokazano je u uzorcima dva poljska i jednog običnog šumskog miša. Svi pozitivni miševi ulovljeni su 2014.godine u mjestu Lipovljani kada je relativna brojnost glodavaca bila je izuzetno visoka (91%) u usporedbi sa svim ostalim izlovima (1-43%). Dobiveni rezultati daju prevalenciju tularemije među populacijom mišolikih glodavaca od 3,3% (3/91) na području ulova odnosno 0,67% (3/449) ukoliko promatramo ukupan broj pretraženih glodavaca.
Ovim istraživanjem utvrdili smo prisutnost bakterije F.tularensis među populacijom mišolikih glodavaca i povezali povećanu pojavnost bakterije u populaciji glodavaca s povećanom brojnošću populacije. Dobiveni podatci upućuju i na moguću svezu između povećane pojavnosti F.tularensis u glodavaca i F. tularensis u ljudi. Daljnja istraživanja neophodna su kako bismo potpunije razumjeli epizootiološko/epidemiološki ciklus F.tularensis u endemskim žarištima Republike Hrvatske.

Abstract (english)

Tularemia is a zoonosis caused by a Gram-negative, coccobacillary, non-motile, aerobic bacterium Francisella tularensis. The main reservoirs of the disease are hares and rodents, and the most important vectors are ticks. Even though considered endemic, lately there has been an increase in incidence throughout Europe with an occasional appearance of mostly minor, closed epidemics. Alongside other factors, the increased incidence is also linked to climatic changes that favor the spread and an increase in numbers of rodents (reservoirs) and ticks (vectors). Aim of this study was to determine the frequency of the infection in small rodents and mammals within the endemic areas of the Republic of Croatia. For this purpose, 449 liver samples were tested by real-time PCR method. Data on relative density and the distribution of certain species of rodents at different hunting sites were collected and analyzed. Obtained results indicate that neither the density of the rodent population nor the distribution of species were equal on all hunting sites. Fluctuations in numbers were also noted on the same sites, depending on the date of the hunt. The presence of F. tularensis was detected in two striped field mice and one wood mouse. All positive animals were caught in 2014. in Lipovljani when the relative numbers of rodents were extremely high (91%) compared to other hunts (1-43%). The gotten results indicate tularemia prevalence among the population of small rodents of 3.3% (3/91) in that area, or 0.67% (3/449) when observing the overall number of tested rodents.
With this research we have determined the presence of F. tularensis within the population of small rodents and connected the increased incidence of the bacteria in the population of rodents with the increased abundance of rodents. The results of the research also indicate a possible connection between the increased frequency of F. tularensis in rodents and increase incidence of the disease in humans. Further research is necessary in order to better comprehend the epidemiologic cycle of F. tularensis in endemic foci of the Republic of Croatia.

• Keywords: mišoliki glodavci; tularemija; PCR
• Keywords (english): mice-like rodents; tularemia; PCR
• Language: croatian
• URN:NBN: urn:nbn:hr:178:221403
• 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: 2018-07-24 10:49:28