Mycobacterium microti

Mycobacterium microti


 * Member of the Mycobacterium tuberculosis complex (MTBC)
 * Also known as the 'Vole bacillus'
 * Etymology: microtus is a genus that includes the vole.

Description
Gram-positive, nonmotile and acid-fast rods.

Colony characteristics
 * Variable colony morphology, buff in colour, either rough or smooth.

Physiology
 * Growth on glycerol-free egg media at 37°C within 28-60 days. May adapt tolerance to glycerol.
 * Sensitive to isoniazid, ethambutol, rifampin, streptomycin and pyrazinamide.

Differential characteristics
 * A commercial hybridisation assay (AccuProbe) to identify members of the M. tuberculosis complex exists.
 * All members of the M. tuberculosis complex share identical 16S rDNA and internal transcribed spacers (ITS) sequences
 * But molecular differentiation is possible by gyrB sequence polymorphism

Pathogenesis

 * Cause of naturally acquired generalised tuberculosis in voles.
 * Recently van Soolingen et al. reported about the first infections among humans caused by M. microti
 * Losing pathogenicity on repeated subculture.
 * Biosafety level 3

Type Strain
Strain ATCC 19422 = CIP 104256 = NCTC 8710.