Recurrent soft tissue abscesses caused by Legionella cincinnatiensis

Recurrent soft tissue abscesses of the jaw, wrist, and arm developed in a 7 3-year-old housewife with nephrotic syndrome and immunoglobulin A(kappa) ga mmopathy of unknown etiology. Conventional cultures remained negative, desp ite visible gram-negative rods on microscopy. Broad-spectrum PCR revealed L egionella cincinnatiensis, which was confirmed by isolation of the organism on special Legionella medium. Infections due to Legionella species outside the lungs are rare. L. cincinnatiensis has been implicated in only four ca ses of clinical infection; these involved the lungs in three patients and t he central nervous system in one patient. We conclude that broad-spectrum P CR can be a valuable tool for the evaluation of culture-negative infections with a high probability of bacterial origin and that Legionella might be a n underdiagnosed cause of pyogenic soft tissue infection.