PREVENTION OF CLOSTRIDIUM DIFFICILE-ASSOCIATED ENTEROCOLITIS BY BIFIDOBACTERIA

TREJO, FERNANDO M; P. F. PÉREZ; DE ANTONI G. L

Simposio; International and Latin American Clostridium difficile Symposium. Brazil. 2014; 2014

Clostridium difficile is a spore former microorganism responsible for 90-100 % of cases of pseudomembranouse colitis, 60-75% of antibiotic-associated colitis and 30-60 % of antibiotic-associated diarrhea. Disruption of the balance of the intestinal microbiota by administration of proton pump inhibitors or antibiotics such as clyndamicin and cephalosporins lead to the overgrowth of C. difficile in the large bowel. The main virulence factors of this microorganism are two large protein toxins TcdA (enterotoxin, 308 kDa) and TcdB (cytotoxin, 260 kDa). Evidence suggests that potentially probiotic microorganisms such as Lactobacillus and Bifidobacterium constitute an alternative approach to prevent/treat C. difficile associated diarrhea (CDAD). However, the mechanism/s by which these bacteria exert the protective effect has not been completely elucidated. The aim of this work was to evaluate the ability of B. bifidum strain CIDCA 5310 to antagonize C. difficile infection in a hamster model of enterocolitis. Preliminary in vitro studies allowed to stablish that B. bifidum 5310 was able to inhibit TcdA and TcdB production. Hamsters (45-60 days old) were treated with B. bifidum 5310 108 cfu/ml or placebo administered in drinking water (day 0). Afterwards, animals received by intragastric gavage (i.g.) 3 mg/animal of clyndamicin (day 7). On day 11 all the animals were infected i. g. with  108 cfu C. difficile strain 117. On day 14 animals were sacrified and cecal content was tested for biological activity on Vero cells. Samples of ceca were analyzed by hematoxylin/eosin staining. Enterocolitis (EC) development and survival were evaluated as the main signs of C. difficile infection. The ratio of animals positive for EC and the ratio of deaths were 11/13 and 4/13 respectively in the placebo group. In contrast the bifidobacteria-treated group presented ratios of EC and death of 3/13 and 0/13 respectively. This represents a significant beneficial effect (p