Clostridium difficile (Clostridioides difficile) is a Gram-positive, anaerobic bacterium that forms resistant spores and is one of the most important human and animal pathogens. The bacterium is often associated with hospital infections, but in recent years, the number of infections in the community has increased as well. C. difficile spores are also found in natural habitats, households and in food. The purpose of this master's thesis was to determine and monitor the frequency and diversity of C. difficile genotypes in compost samples. We sampled two composters at different time points and from five different sampling points, to obtain 45 compost samples. We used two approaches, the direct method and the sonication, to isolate C. difficile from the obtained samples. For molecular characterization of isolates, PCR-ribotyping and toxinotyping were used. C. difficile was isolated from 38 compost samples (84.4%). In total, 906 isolates were isolated and then classified into 35 different PCR-ribotypes. 77.1% of PCR-ribotypes were toxigenic and belonging to the toxinotypes 0, 0 / v, III, V, and VIII. The most common C. difficile PCR-ribotypes in compost samples were 018, 014/020, and SLO 057. It makes sense to use both methods, direct method and the sonication, to isolate the bacterium. Our results confirm that compost can be a potential source of infection with C. difficile bacterium, since it is present in high percentages in compost samples. Compost also contains various C. difficile PCR-ribotypes, which overlap with PCR-ribotypes in humans, animals, the environment and foods in Slovenia.
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