Epidemiology and chemotherapy of opportunistic infections due to Pseudomonas and Klebsiella.

Pseudomonas and Klebsiella are now important agents of opportunistic infection. They are widely distributed in nature, and both groups consist of many distinct types. The distribution of types of Pseudomonas aeruginosa is the same in infections and in faecal carriers and this suggests that carriers may be a major source of infecting strains. Gentamicin is effective against almost all strains of pseudomonas; carbenicillin, though not effective alone against as high a proportion of strains, acts synergistically with gentamicin. The epidemiology of Klebsiella infections is poorly understood; symptomless colonization of patients with Klebsiella is frequently the preliminary to clinical infection. Klebsiella strains show a wide range of patterns of antibiotic sensitivity, and multiresistant strains very often owe their resistance to the acquisition of R factors.