Induction of oxidative DNA damage in anaerobes

We compared oxidative DNA damage in strictly anaerobic Prevotella melaninogenica, aerotolerant anaerobic Bacteroides fragilis, and facultative anaerobic Salmonella typhimurium after exposure to O-2 or H2O2. Using HPLC with electrochemical detection, we measured 8-hydroxydeoxyguanosine (8OHdG) as a damage marker, O-2 induced 8OHdG in P. melaninogenica but not in B. fragilis, which shows catalase activity, or in S. typhimurium. In P. melaninogenica, with catalase, O-2 induced less 8OHdG; superoxide dismutase had no effect; with glucose and glucose oxidase, O-2 induced more 80HdG. H2O2 also markedly increased 8OHdG. O-2 was suggested to induce 8OHdG through H2O2. O-2 or H2O2 decreased survival only in P. melaninogenica. Highly sensitive to oxidative stress, P, melaninogenica could prove useful for investigating oxidative DNA damage. (C) 1999 Federation of European Biochemical Societies.