Abstract
The effects of sulphasalazine (SASP), azodisal sodium (ADS), and their metabolites were tested in vitro on aerobic and anaerobic faecal bacterial strains. Sulphapyridine (SP) had a mild to moderate effect on Escherichia coli and Streptococcus faecalis. SASP also had a growth-inhibitory effect on Strep, faecalis. The other substances had no effect on the aerobic strains. SASP, SP, 5-aminosalicylic acid, and, to a certain extent, N-acetyl 5-aminosalicylic acid exerted a growth-inhibitory effect on the anaerobic strains. Of special interest was the inhibitory effect on Clostridium difficile strains. In recent years the possibility that overgrowth of CI. difficile could cause flare-ups of inflammatory bowel disease has been discussed. Some studies suggested that SASP treatment could predispose to CI. difficile superinfection, whereas others found SASP more probable to exert a prophylactic effect. Our findings support the theory that SASP treatment reduces rather than promotes the risk of CI. difficile superinfection.