Gram-negative bacillary infections in cancer patients.

The majority of infectious complications in cancer patients are caused by Gram-negative bacilli. The most common organisms are Escherichia coli, Klebsiella spp. and Pseudomonas aeruginosa. Sites of infection are related to the patients' underlying malignancies, but pneumonia and septicaemia occur most often. Important newer antibiotics for the therapy of these infections are aminoglycosides and semisynthetic penicillins. It is advisable to utilize combinations of antibiotics for serious infections in cancer patients, and therapy should be instituted promptly at the onset of infection.