AbstractThe aim of the research was to determine the intestinal carriers of C. difficile in different human population groups in Serbia. The research enrolled 877 persons with formed stools: (newborn children in maternity hospitals for up to two weeks old) (23), group A; children aged from two weeks to two years (121), group B; children aged two to 10 years (54), group C, healthy individuals aged 10 and over (516), group D; patients hospitalized for at least 48 hours (100), group E; staff of the Clinical Center in Nis, Serbia, (63), group F. The toxins A and B of C. difficile were detected by ELISA-ridascreen Clostridium difficile Toxin A/B (R — Biopharm AG, Darmstadt, Germany). The toxin A of C. difficile was detected using ColorPAC Toxin A test (BectonDickinson, New Jersey, USA). Out of the total number of persons (877), the carriers of certain types of toxin-producing strains of C. difficile were distributed as: 6.04% (A−/B−), 1.83% (A+/B+) and 0.11% (A−/B+). In most groups (5/6), the dominance of non-toxigenic (A−/B−) isolates was established, with the rate of carriers 1.75 – 30.43% depending on the group. Toxigenic isolates were prevalent only in the group F in relation to non — toxigenic (7.94% versus 4.76% of persons). In other groups, the carriers of toxigenic strains ranged from 0.00 – 17.45%. The presence of asymptomatic intestinal carriers of C. difficile in the human population, indicate the possible reservoirs and sources of infection.