Provider: - Institution: - Data provided by Europeana Collections- Toxoplasmosis, infection caused by the parasite Toxoplasma gondii, is one of the most widespread zoonoses in the world and it has been estimated that up to one third of the global human population is infected with this parasite. Although serological tests are the primary method in the routine diagnosis of toxoplasmosis, interpretation of the results can be not only difficult and time-consuming, but they can be inconclusive. Therefore, the introduction of highly sensitive molecular methods, by which results can be obtained within a day, into the diagnosis of toxoplasmosis is of great importance. The aim of this research was the introduction of molecular methods into the diagnosis of toxoplasmosis for the first time in Serbia, as well as genotypization of the isolated T. gondii strains. This study included 160 human biological samples from 127 patients serologically suspected of toxoplasmosis in which the presence of T. gondii was analyzed by PCR and by bioassay in mice. It was found that the detection of T. gondii DNA in human biological materials depends on the type of sample as well as on the initial volume. Real-time PCR was positive in 30.8% of peripheral blood samples, 33.3% of cord blood samples, 35.7% of amniotic fluid samples, 57.1% of CSF samples and 60% of humor aqueous samples. The detection rate of T. gondii by molecular methods was higher than by bioassay, in both blood samples from adults suspected of acute toxoplasmosis and samples from fetuses and newborns suspected of congenital toxoplasmosis. The results of this study emphasize the huge practical importance and potential of molecular diagnostics and show the benefit of introducing this method as part of the standard protocol for the diagnosis of toxoplasmosis. T. gondii has a wide range of host organisms, including all warm-blooded animals, so that in the second part of this research molecular methods for the detection of this parasite were applied in animal material, rodents specifically. Rodents were chosen because of their potentially important role as a link in the transmission chain of T. gondii infection. A total of 156 brain samples from 144 brown rats (Rattus norvegicus) and 12 house mice (Mus musculus) were analyzed. T. gondii DNA was vi detected in 10.4% of rats and in as many as 83.3% of house mice. The rate of positive findings in rats and mice collected in Belgrade is an indicator of the degree of contamination of the urban environment with T. gondii, reflecting a considerable public health risk. Finally, this research provides the very first and original phylogenetic data on T. gondii population structure in Serbia. Recent studies performed world-wide indicate the existence of a clonal population structure characterized by three main, widespread clonal lineages (I, II and III), of which types I and II are predominant in Europe and North America. There are also recombinant and atypical strains that are mainly present in South America and Africa. In this study, the identification of the T. gondii clonal type was performed in 22 samples, 19 from humans and three from rats, using the PCRRFLP method. Genotyping was successful in five human samples of which four isolates originating from cases of congenital toxoplasmosis, toxoplasmosis in pregnancy and bone marrow transplantation were type II, while one isolate from a case of congenital toxoplasmosis was type I. These results, first for the Southeastern Europe, indicate the predominance of genotype II in our country, as well as in most of the Europe.- Toksoplazmoza, oboljenje koje izaziva parazit Toxoplasma gondii, jedna je od najrasprostranjenijih zoonoza u svetu, i procenjuje se da je čak jedna trećina čovečanstva inficirana ovim parazitom. Iako serološki testovi predstavljaju primarnu metodu u rutinskoj dijagnostici toksoplazmoze, interpretacija rezultata seroloških analiza u nekim kliničkim slučajevima može biti komplikovana i dugotrajna, a neretko i nedovoljno informativna. Zbog toga je uvođenje molekularnih metoda koje inače odlikuje velika osetljivost i pomoću kojih je moguće dobiti rezultate u kratkom vremenskom periodu, od velikog značaja za dijagnostiku toksoplazmoze. Otuda je cilj ovog istraživanja bio uvođenje molekularne dijagnostike toksoplazmoze po prvi put u Srbiji, kao i genotipizacija izolovanih sojeva T. gondii. Ovom studijom je obuhvaćeno 160 uzoraka poreklom od 127 pacijenata serološki suspektnih na toksoplazmozu, kod kojih je prisustvo T. gondii analizirano PCR-om u realnom vremenu i biološkim ogledom. Pokazano je da uspešnost dokazivanja DNK T. gondii u materijalu humanog porekla zavisi kako od tipa materijala tako i od ukupne zapremine materijala od kojeg se uzima uzorak. Tako je PCR u realnom vremenu bio pozitivan u 30,8% uzoraka periferne krvi, u 33,3% uzoraka krvi iz pupčanika, u 35,7% uzoraka plodovih voda, u 57,1% uzoraka likvora i u 60% uzoraka očnih vodica. U odnosu na izolaciju parazita biološkim ogledom, pokazana je znatno viša stopa detekcije DNK T. gondii, i to i u uzorcima krvi od pacijenata suspektnih na akutnu toksoplazmozu tako i u onima poreklom od fetusa i novorođenčadi suspektnih na kongenitalnu toksoplazmozu. Dobijeni rezultati ukazuju pre svega na veliki potencijal i praktični značaj molekularne dijagnostike kao i na potrebu uvođenja ove metode kao dela standardnog protokola za dijagnostiku toksoplazmoze. T. gondii ima veoma širok spektar domaćina koji uključuje sve toplokrvne životinje, te su u drugom delu ovog istraživanja molekularne metode za detekciju toksoplazmoze primenjene na materijalu životinjskog porekla, i to konkretno od glodara. Zbog njihove potencijalno značajne uloge kao karike u epidemiološkom lancu toksoplazmoze u okviru ove studije ispitano je i 156 uzoraka poreklom od 144 braon pacova (Rattus norvegicus) i 12 kućnih miševa (Mus musculus). DNK T. gondii je detektovana u mozgu 10,4% pacova i kod čak 83,3% kućnih miševa. Relativno visoka stopa pozitivnih nalaza kod pacova i miševa sakupljenih u Beogradu ukazuje na kontaminiranost naše sredine parazitom T. gondii koja predstavlja rizik za javno zdravlje. Poslednji deo ovog rada se odnosi na prva i poptuno originalna filogenetska istraživanja populacione strukture T. gondii. Naime, skorašnja istraživanja u svetu ukazuju na postojanje klonske populacione strukture koju karakterišu tri široko rasprostranjena glavna klonska tipa (I, II i III), od kojih su tipovi I i II predominantni u Evropi i Severnoj Americi. Postoje takođe i rekombinantni i atipični sojevi koji su uglavnom prisutni u Južnoj Americi i Africi. U ovom istraživanju određivanje klonskog tipa, čime su dobijeni i prvi podaci o populacionoj strukturi T. gondii u Srbiji, vršeno je korišćenjem PCR-RFLP metode. Analizirano je ukupno 22 uzorka i to 19 humanog porekla i 3 poreklom od pacova. Uspešno je genotipizirano pet uzoraka poreklom od ljudi, za koje se pokazalo da četiri pripadaju tipu II a jedan tipu I. Sojevi tipa II su izolovani iz kliničkih uzoraka bolesnika sa kongenitalnom toksoplazmozom, toksoplazmozom stečenom u trudnoći i reaktivacijom infekcije usled post- transplantacione imunosupresije, dok je soj tipa I izolovan iz jednog uzorka poreklom od kongenitalno inficiranog novorođenčeta. Ovi rezultati, prvi za čitavo područje Jugoistočne Evrope, pokazuju da je i u našoj zemlji, kao i u većem delu Evrope, predominantan pre svega genotip II.- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana