Bacteriology and treatment of primary lung abscess.

Abstract

A prospective study of bacteriology and therapeutic outcome in 26 cases of primary lung abscess is reported. Bacteriologic results were based on percutaneous transtracheal aspirates obtained before antimicrobial therapy. Anaerobic bacteria were recovered from 24 patients. The principal isolates were Fusobacterium nucleatum, Bacteroides melaninogenicus, and anaerobic gram-positive cocci. Bacteroides fragilis, of interest for its unique antibiotic susceptibility pattern, was recovered from 4 patients. Aerobic or facultative bacteria were present in 10 patients but were the exclusive isolates in only 2. Antimicrobial therapy was selected on the basis of the bacteriologic findings. This was judged successful in all cases, although 2 patients died from concurrent conditions before their pulmonary infection was cured.