Treatment of anaerobic pulmonary infections; carbenicillin compared to clindamycin and gentamicin.

Twenty-three patients with anaerobic infections of the lung were treated with either two antibiotics, clindamycin and gentamicin (11 patients) or with a single antibiotic, carbenicillin (12 patients). Cultures were obtained prior to therapy, either by transtracheal needle aspiration (17 patients) or thoracocentesis (six patients). Anaerobic bacteria were found in all. Fifteen patients had aerobic and facultative bacteria in addition. The anerobic isolates were peptostreptococci (12), peptococci (12), Bacteroides organisms (eight), clostridia (three), actinomycetes (two), eubacteria (one), and fusobacteria (one). Aerobes included streptococci (nine), enterococci (seven), Neisseria organisms (two), Klebsiella organisms (one), Citrobacter organisms (one), Pseudomonas organisms (one), Mycobacterium tuberculosis (two), and Nocardia (one). The two patients with pulmonary tuberculosis with anaerobic and superinfection received antituberculosis chemotherapy in addition. Therapeutic response was considered excellent in both groups. This suggests that carbenicillin may be used as a single antibiotic in the treatment of anaerobic and mixed infections of the lung.