Extrapulmonary and disseminated infections due to Mycobacterium malmoense: case report and review

Mycobacterium malmoense is a potentially pathogenic species that was first described in 1977. During the past decade M. malmoense has been recognized with increasing frequency as a pulmonary pathogen. More than 180 cases of M. malmoense infection have been reported. Most of these infections affected a previously damaged lung. Other infection sites included the skin, lymph nodes, and bursae. Five cases of disseminated infection have been reported. The antituberculous drugs associated with the most favorable susceptibility patterns are rifampin and ethambutol. Because of the slow growth of M. malmoense on conventional, egg-based bacteriologic media, the incubation time should be > 6 weeks; special solid and liquid media are recommended. We report a case of disseminated pulmonary and gastrointestinal infection due to M. malmoense in a patient with AIDS, who was treated successfully with a combination of rifabutin (ansamycin), clofazimine, and isoniazid. In addition, we review the characteristics of extrapulmonary and disseminated infections due to M. malmoense.