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Bakterija Clostridium difficile (Clostridioides difficile) spada med najpomembnejše povzročiteljice bolnišničnih črevesnih okužb, število okužb narašča tudi v domačem okolju. Naravni rezervoar bakterije je predvsem črevesje otrok in mladih živali, najdemo jo tudi v različnih naravnih okoljih, vodi, tleh, gospodinjskih površinah in hrani. Namen magistrske naloge je bil ugotoviti občutljivost gojitvene metode za osamitev bakterije C. difficile iz različnih vzorcev zelene solate in s površine krompirja ter ugotoviti pogostnost in raznolikost genotipov bakterije C. difficile na površini krompirja, ingverja in v vzorcih zelene solate. Za osamitev bakterije iz vzorcev zelenjave smo uporabili metodo, ki je vključevala bogatitev in osamitev bakterije C. difficile na selektivnem kromogenem gojišču po alkoholnem šoku bogatitvene kulture. Testirali smo 98 vzorcev zelenjave 52 vzorcev krompirja, 31 vzorcev zelene solate in 15 vzorcev ingverja. Bakterijo C. difficile smo izolirali iz 14,3 % (14/98) vzorcev zelenjave, od tega iz 13,5 % vzorcev krompirja, 19,4 % vzorcev zelene solate in 6,7 % vzorcev ingverja. Osamili smo 124 izolatov bakterije C. difficile, ki smo jih s pomočjo PCR-ribotipizacije razvrstili v 15 različnih PCR-ribotipov. Skoraj polovica izolatov je bila toksigenih (46,7 %). Toksigeni sevi so pripadali toksinotipoma 0 in III. Najpogostejši PCR-ribotipi so bili SLO 214 (netoksigeni), 011/049 in 014/020 (toksinotip 0). Nobena okužba z bakterijo C. difficile še ni bila neposredno povezana s hrano, vendar bi na podlagi naših rezultatov lahko povzeli, da zelenjava predstavlja potencialni vir okužbe, saj smo na zelenjavi našli PCR-ribotipe, ki povzročajo okužbe pri ljudeh. Bacteria Clostridium difficile (Clostridioides difficile) is among the most important causes of hospital intestinal infections. In recent years the number of community-associates infections has also increased. The main natural reservoir of the bacteria is the intestine of children and young animals but C. difficile can be found in different environments such as water, soil, household surfaces and food. The aim of our study was to determine the detection limit of the cultivation method for the isolation of C. difficile from lettuce and potato samples, and to determine the prevalence and variability of C. difficile genotypes on the surface of potatoes, ginger and in lettuce. For the isolation of bacteria from vegetable samples, we used the method which included the isolation of C. difficile on a selective chromogenic medium, after the ethanol shock of the enrichment culture. A total of 98 vegetable samples were tested 52 potato, 31 lettuce and 15 ginger samples. The overall prevalence of C. difficile on vegetables was 14,3 % (14/98) 13,5 % on potato samples 19,4 % on lettuce samples and 6,7 % on ginger samples were positive, respectively. One hundred and forty two isolates were distributed into 15 different PCR-ribotypes. Almost half of the vegetables isolated were toxigenic (46,7 %) and belonged to toxinotype 0 and III. The most prevalent PCR-ribotypes were SLO 214 (non-toxigenic), 011/049 and 014/020 (toxinotype 0). Infection with C. difficile has not yet been directly linked to contaminated food, but on the basis of our results we can conclude that vegetables represent a possible source for human infections since we found in the vegetables the same PCR-ribotypes, that cause C. difficile infections in humans. |
