Quantitative culture of bronchoalveolar lavage from patients with anaerobic lung abscesses.

The study of anaerobic infections of the lung is usually limited to the use of invasive techniques such as transtracheal aspiration (TTA) to avoid contamination by oral flora. Bronchoalveolar lavage (BAL) has been used successfully in the study of the etiology of pneumonia in immunocompromised patients. This study evaluated the role of the quantitative culture of BAL in the diagnosis of lung abscess. Four episodes of lung abscess in three patients were studied, and the results of quantitative culture of BAL were compared with those of the standard technique of TTA. Nineteen anaerobic bacterial species were recovered from the BAL fluid, all but one at concentrations greater than 10(3) cfu/ml. Culture of BAL fluid yielded 18 of 22 of the isolates cultured from TTA, including 12 of 16 of the anaerobic bacteria. This study suggests that quantitative culture of BAL fluid may be useful in the bronchoscopic evaluation of lung abscess.