Quantitative Culture of Bronchoalveolar Lavage from Patients with Anaerobic Lung Abscesses

Abstract

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.

The Importance of Obligate Anaerobes and the <b><i>Streptococcus anginosus</i></b> Group in Pulmonary Abscess: A Clone Library Analysis Using Bronchoalveolar Lavage Fluid

“…The detection rate of these bacteria was less than half of the cases in cultures in this study, and the prevalence of these oral bacteria might be underestimated in real-world clinical settings. Similarly to a former report, which described a link between the aspiration of oral flora and lung abscess development [20], our results also indicate the important and close relationship between oral bacterial flora and lung abscess. Therefore, physicians should be more aware of the S. anginosus group as primary pathogens of lung abscess.…”

Abscesso pulmonar de aspiração: análise de 252 casos consecutivos estudados de 1968 a 2004

“…(15,17) Aerobic and anaerobic bacteria are aspirated from the mouth into the lung during the period of unconsciousness, but, also, they are still present in the patient mouth after the establishment of the lung abscess. Therefore, bacteria grown in routine cultures (under aerobic conditions) certainly do not indicate the true or full sequence of events occurring within the lung, especially when the material examined is sputum.…”

“…The visualization of mixed flora in (gram) cultures of the secretions strongly indicates the presence of anaerobic microorganisms, and this is extremely useful for making a quick working diagnosis. The definite identification of these bacteria, however, requires the culture of the material collected (with protection) under anaerobic conditions, (13)(14)(15) which, in practice, is rarely necessary for the correct implementation of the treatment. It must be emphasized, however, that the routine sputum cultures carried out under anaerobic conditions do not show anaerobic bacteria, revealing only the growth of accompanying aerobic microorganisms, such as non-hemolytic streptococcus, pneumococcus or some gram-negative cocci.…”

Acute Pneumonia and its Complications

“…Quantitative culture of bronchoalveolar lavage fluid improves the accuracy of identification of aerobic and anaerobic bacteria as causes of lung abscess. 153 Ultrasound or CT-guided transthoracic aspiration of lung abscess performed on complex cases, successfully identifies the etiologic agent in >90% of cases. 154…”