Role of anaerobic bacteria in spontaneous peritonitis of cirrhosis: report of two cases and review of the literature.

The role of anaerobic or microaerophillic bacteria in spontaneous peritonitis of cirrhosis has not been clearly defined. Among 126 cases recorded in the literature, in only eight (6 per cent), including the two reported here, was bacterascites associated with anaerobic or microaerophilic bacteria. Clinical features in these cases were indistinguishable from those associated with aerobic bacteria. However, polymicrobial bacterascites occurred in four of eight cases associated with anaerobes, as contrasted with only 10 of 118 cases (8 per cent) associated with aerobes alone. On the other hand, concurrent bacteremia occurred in only one of eight cases associated with anaerobes as contrasted with 52 of 118 cases (44 per cent) of aerobic spontaneous peritonitis. Experimental evidence is cited in an attempt to explain this relatively low incidence of spontaneous peritonitis associated with anaerobic or microaerophilic bacteria, despite the high density of these organisms in the normal bowel flora.