The microflora of chronic pleural empyema. An analysis of 89 patients.

Bacteriological cultures from 89 patients with chronic pleural empyema were studied. Seventy-nine patients had positive and 10 negative culture results. Forty-eight patients had a single isolate--pyogenic cocci in 32 and Gram-negative enteric bacilli in 16--and multiple organisms were grown in 31 patients. Anaerobic organisms were recovered in 6,2%. Our negative culture rate of 11,2% may reflect failure to recover anaerobes, but could represent sterilization of the empyema by prior use of antibiotics. The results of antibiotic sensitivity tests and the pathogenicity of the organisms recovered suggest that the choice of antibiotic combinations for chronic pleural empyema requires careful consideration.