Mycobacterium simiae

M. simiae is a rarely isolated mycobacterial species that is also reported to occur in the environment (Griffith DE et al. 2007). In rare cases, M. simiae is responsible for pulmonary infections; extra-pulmonary localizations are rare. As with infections caused by other nontuberculous mycobacteria, AIDS and presumably other immunodeficiencies are risk factors for M. simiae infection.

In larger collectives, M. simiae were identified from blood in 4.2% of patients. In these patients, fever was the most common symptom. There are other reports of disseminated disease caused by M. simiae in the world literature (Narang R et al. 2010). These infections were detected during prospective blood culture studies in febrile adult HIV-positive hospitalized patients in these two countries. In disseminated infections caused by M. simiae, lesions of the skin may occur, albeit rarely, usually in the form of disseminated, papular, or nodular infiltrates Narang R et al. 2010).

M. simiae is resistant to nearly all antibiotics in the resistance assay (Griffith DE et al. 2007). Clarithromycin, moxifloxacin, and protionamide (PTH) may be sensitive. An optimal combination and duration of therapy has not been established. Treatment that includes clarithromycin, moxifloxacin, and trimethoprim/sulfamethoxazole is recommended (Griffith DE et al. 2007).

1. Fukano H et al. (2018) Mycobacterium shigaense sp. nov. a slow-growing, scotochromogenic species, is a member of the Mycobacterium simiae complex. Int J Syst Evol Microbiol 68:2437-2442.
2. Griffith DE et al (2007) Am J Respir Crit Care Med 175: 367-416.
3. Narang R et al (2010) Disseminated disease caused by Mycobacterium simiae in AIDS patients: a report of three cases. Clin Microbiol Infect 16: 912-914.