Isolation and characterization of clostridium difficile from river sediment

Po Gramu pozitivna anaerobna bakterija Clostridioides (Clostridium) difficile je pogosta povzročiteljica bolnišničnih črevesnih okužb. V zadnjih letih se povečuje število okužb v domačem okolju pri populaciji, ki je bila v preteklosti prepoznana po nizkem tveganju za okužbo. Bakterija tvori odporne endospore, ki ji omogočajo preživetje zunaj gostitelja. Okolje predstavlja enega od možnih rezervoarjev C. difficile. Namen naše naloge je bil raziskati pogostnost bakterije C. difficile v rečnem sedimentu. Vzorčeno je bilo na treh lokacijah vzdolž reke Drave v jesenskem in zimskem letnem času. Skupno je bilo nabranih 6 vzorcev v duplikatih, prisotnost spor bakterije C. difficile je bila dokazana na vseh lokacijah in v vseh vzorcih. Iz vseh vzorcev je bilo osamljenih 335 izolatov C. difficile, ki so bili z metodo PCR-ribotipizacije uvrščeni v 26 različnih PCR- ribotipov. Prevladujoča PCR-ribotipa sta bila 001/072 (29,9 %) in 014/020 (15,5 %), ki sta oba toksigena in sta pogosto povzročitelja okužb pri hospitaliziranih bolnikih v bližnji bolnišnici ter v Sloveniji in v svetu nasploh. Skupno je zgolj 8 PCR-ribotipov pripadalo netoksigenim izolatom, kar predstavlja 30,8 % vseh izolatov. Naši rezultati kažejo, da je rečni sediment bogat rezervoar endospor C. difficile in zaradi visokega deleža toksigenih sevov lahko predstavlja vir okužbe z bakterijo C. difficile.Gram-positive anaerobic bacterium Clostridioides (Clostridium) difficile is a common cause of nosocomial intestinal infections. In recent years, the number of community- acquired Clostridium difficile infection has been increasing, in a population that has been identified in the past for its low risk of infection. The bacterium forms resistant endospores that allow it to survive outside the host. The purpose of our task was to investigate the frequency of C. difficile in river sediment. We sampled at three locations along the river Drava in the autumn and winter seasons. A total of 6 samples were collected in duplicates, and the presence of C. difficile spores was demonstrated at all locations and in all samples. From all samples, 335 C. difficile isolates, which were classified into 26 different PCR ribotypes by the PCR-ribotyping method, were determined. The predominant PCR-ribotypes were 001/072 (29.9%) and 014/020 (15.5%), both of which are toxigens and often cause infections in hospitalized patients in a nearby hospital, in Slovenia, as well as in the world in general. In total, only 8 PCR ribotypes belonged to non-toxigenic isolates, representing 30.8% of all isolates. Our results indicate that river sediment is a rich reservoir of C. difficile endospores and, due to the high proportion of toxic strains, may be a source of C. difficile infection