The effect of nalidixic acid on microaerophilic and anaerobic bacteria. Special study of clostridia.

Study of the sensitivity of 141 strains of anaerobic and microaerophilic bacteria to nalidixic acid shows that few bacteria are inhibited by low concentrations (Veillonella, Eikenella, most of the Clostridia). Nalidixic acid appears to be bactericidal with respect to Clostridium perfringens, and its point of attack in the DNA is probably different from that of metronidazole.