Documentation of Legionella pneumophila and Mycobacterium tuberculosis co-existence in a patient with acute respiratory distress syndrome.

BACKGROUND: Bacterial lung infections are common causes of ARDS and, despite intensive research for decades, the mortality rate remains very high. Only two reports suggest the co-existence of Legionnaires' disease and pulmonary tuberculosis based mainly on clinical presentation and serologic results for Legionella and positive cultures for Mycobacterium tuberculosis (M. tuberculosis).

MATERIALS AND METHODS: A variety of specimens from a 61-year-old man was used for detection of Legionella pneumophila (L. pneumophila) and M. tuberculosis by PCR. Further identification of the pathogens was carried out by sequence analysis.

RESULTS: L. pneumophila region mip was detected in bronchial washings, bronchoalveolar lavage and urine specimens of the patient. M. tuberculosis regions IS6110 and mtp40 were detected in endo-bronchial secretions and bronchoalveolar lavage.

CONCLUSION: By using polymerase chain reaction (PCR) and DNA sequencing we documented L. pneumophila and M. tuberculosis co-existence, in multiple specimens of a patient presenting with acute respiratory distress syndrome (ARDS). Furthermore, the efficacy of the specific antibiotic treatment, based on the PCR results, suggest the co-existence of these two pathogens.