Noxythiolln-resistant organisms in a district general hospital

Twelve strains of Pseudomonas aeruginosa, three strains of Klebsiella aerogenes, and two strains of Escherichia coli were found to be resistant to noxythiolin. Some of the pseudomonads were isolated from patients in the same ward, not all of whom were on noxythiolin treatment. The strains from these patients were indistinguishable from each other on phage typing, which suggested cross-contamination. No Gram-positive organism was found to be resistant to noxythiolin. Noxythiolin should not be used before a disc diffusion sensitivity test has been performed to determine whether the organisms are sensitive to it. This is particularly important when pseudomonads are the offending organisms.