Mycobacterium malmoense

Mycobacterium malmoense is a Gram-positive bacterium from the genus Mycobacterium.

Etymology
From the city of Malmö, Sweden where the strain used for the description was isolated from patients.

Description
Gram-positive, nonmotile, acid-fast and coccoid to short rods.
 * Environmental reservoir: soil and water.

Colony characteristics
 * Smooth and nonpigmented colonies, growth below the surface of semisolid agar medium after deep inoculation (as seen with M. bovis), 0.9 - 1.7mm in diameter.

Physiology
 * Growth on inspissated egg medium and oleic acid-albumin agar at a temperature range of 22 °C-37 °C requires over 1 week.
 * Susceptible to ethambutol, ethionamide, kanamycin and cycloserine.

Differential characteristics
 * Antigenic structure: seroagglutination demonstrates a single serovar distinct from that of other species.

Pathogenesis

 * Usually infects young children with cervical lymphadenitis or adults with chronic pulmonary disease, (mostly with previously documented pneumoconiosis).
 * Rarely causes extrapulmonary diseases and disseminated infections
 * Biosafety level 2
 * The first case of infectious endocarditis by M. malmoense was reported in 2020 in Cali, Colombia. The patient was a 61-year old woman with a history of biological mitral valve replacement due to rheumatic disease, dermatomyositis and rheumatoid arthritis in management with methotrexate, chloroquine, and prednisolone.

Type strain
Strain ATCC 29571 = CCUG 37761 = CIP 105775 = DSM 44163 = JCM 13391 = NCTC 11298.
 * First isolated from sputum and biopsy specimens with pulmonary disease in Malmö, Sweden.