[Pneumonia caused by Legionella micdadei in a fatal case and its bacteriological characteristics]

Community-acquired lung abscess caused by Legionella micdadei in a myeloma patient receiving thalidomide treatment

Legionella infection causes 2 to 14% of community-acquired pneumonia (CAP). Legionella micdadei constitutes <1% of these infections. We describe a case of cavitary L. micdadei CAP in a myeloma patient receiving thalidomide treatment. The importance of considering pneumonia and problems in diagnosing pneumonia caused by L. micdadei in this patient population are reviewed.

Legionella micdadei pneumonia diagnosed by culture isolation and DNA-dNA hybridization from bronchial lavage fluid

An 80-year-old man was admitted because of dyspnea on effort. We suspected an acute exacerbation of chronic heart failure and idiopathic interstitial pneumonia caused by right-sided pneumonia. A nodular shadow in right upper lobe spread and consolidated into the airspace, and it failed to improve despite administration of meropenem trihydrate, vancomycin hydrochloride and clindamycin. A definitive diagnosis of Legionella micdadei pneumonia was made on the basis of this organism being isolated in culture from bronchial lavage fluid and subsequent identification of Legionella micdadei using DNA-DNA hybridization. The airspace consolidation gradually improved following treatment with intravenous erythromycin and minocycline hydrochloride.