Prevalencija bakterija iz roda Leptospira u populaciji mišolikih glodavaca

master's thesis

• Title (english): Prevalence of Leptospira spp. in Population of Small Rodents
• Author: Roberta Čordaš
• Mentor: Josipa Habuš (mentor)
• Committee member: Suzana Hađina (predsjednik povjerenstva)
• Committee member: Matko Perharić (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: 2019-07-11, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Veterinary Medicine; Veterinary Public Health and Food Safety

Abstract

Leptospiroza je (re)emergentna zarazna bolest mnogih domaćih i divljih životinja i čovjeka uzrokovana patogenim bakterijama iz roda Leptospira. To je tipična bolest prirodno žarišnog tipa čija je epizootiologija i epidemiologija usko vezana uz pojedine životinjske vrste koje nose i izlučuju pojedine serovare leptospira u okoliš. Glavni izvor leptospira predstavljaju mišoliki glodavci i štakor (rezervoari leptospiroze) koji od leptospiroze ne oboljevaju, a predstavljaju doživotne kliconoše. Ciljevi ovog istraživanja bili su utvrditi učestalost infekcije u mišolikih glodavaca te utvrditi osjetljivost pojedinih metoda koje u tu svrhu možemo rabiti. Bubrezi 186 mišolikih glodavaca izlovljenih na sedam izdvojenih lokaliteta unutar endemskih područja leptospiroze Republike Hrvatske pretraženi su paralelno metodom izdvajanja i metodom lančane reakcije polimerazom u stvarnom vremenu. Metodom renokulture ustanovljeno je 9/186 pozitivnih uzoraka (4,83%), a lančanom rakcijom polimerazom 20/186 (10,75%). Veća osjetljivost lančane reakcije polimerazom u stvarnom vremenu te činjenica da se njome mogu pretraživati i djelomično autolitični uzorci čine ovu metodu dobrim izborom u istraživanjima kliconoštva u populaciji mišolikih glodavaca. Ipak, nemogućnost identifikacije dokazanog soja razlog je zašto metoda izdvajanjem ne može u potpunosti biti zamijenjena bržim i osjetljivijim molekularnim metodama. Prisutstvo bakterija iz roda Leptospira utvrđeno je u pet od sedam pretraživanih vrsta što potvrđuje ulogu mišolikih glodavaca u održavanju endemskih žarišta leptospiroze. Najviši stupanj kliconoštva (30%) utvrđen je na širem području Velike Gorice. Ovakav rezultat može se pokušati objasniti činjenicom da to područje pripada u sliv rijeke Save i da ima veliki poplavni potencijal, a vlažna područja omogućuju duži opstanak leptospira u okolišu. Kako bi se dodatno istražili biotički i abiotički čimbenici koji utječu na brojnost populacije mišolikih glodavaca i postotak inficiranosti leptospirama trebalo bi provesti longitudinalnu studiju koja bi pratila kliconoštvo te ostale čimbenike na istim lokalitetima ali kroz dulje vrijeme.

Abstract (english)

Leptospirosis is a (re) emerging zoonosis of many domestic and wild animals and humans, caused by pathogenic bacteria from the genus Leptospira. It is a naturally foci disease with epizootiology and epidemiology closely linked to carrier species that excrete certain serovars of Leptospira to the environment. The main reservoirs of leptospira are rats and small rodents that do not suffer from clinical disease and are lifelong carriers. The aim of this study was to determine the shedding rate in small rodents in areas where leptospirosis appears endemic and to determine the sensitivity of methods used to detect the frequency of rodent infections. Renal culture and real-time polymerase chain reaction (qPCR) were used to test kidney specimens of 186 animals, trapped in seven endemic regions of Croatia. Using the isolation method we obtained nine positive samples (4,83%), while 20 (10,75%) positive samples were detected by qPCR. Molecular methods had higher sensitivity and we were able to obtain positive result even on autolyzed samples. However, due to the fact that serological determination cannot be achieved by molecular methods, isolation is still considered important in this kind of epidemiological investigations. During this investigation Leptospira spp. were detected in five out of seven small rodents species with the highest degree of shedding (30%) detected in the Velika Gorica municipality. Those findings can be because this area belongs to the river Sava basin and have high flooding potential and humid areas allow longer survival of leptospira in the environment. Further longitudinal studies are needed in order to identify all abiotic and biotic factors that can affect the density of rodent population and shedding rates.

• Keywords: Leptospira; mišoliki glodavci; Real Time PCR; renokultura
• Keywords (english): Leptospira; small rodents; Real Time PCR; isolation
• Language: croatian
• URN:NBN: urn:nbn:hr:178:970494
• 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: 2020-01-28 11:50:37