Mycobacterium gastri

Mycobacterium gastri is a species of the phylum Actinomycetota (Gram-positive bacteria with high guanine and cytosine content, one of the dominant phyla of all bacteria), belonging to the genus Mycobacterium.

Mycobacterium gastri
Scientific classification
Domain:	Bacteria
Kingdom:	Bacillati
Phylum:	Actinomycetota
Class:	Actinomycetes
Order:	Mycobacteriales
Family:	Mycobacteriaceae
Genus:	Mycobacterium
Species:	M. gastri
Binomial name
Mycobacterium gastri Wayne 1966, ATCC 15754

Description

Moderately long to long, Gram-positive, aerobic, nonmotile and acid-fast rods.

Colony characteristics

• Nonchromogenic, smooth to rough, white colonies on Löwenstein-Jensen medium and smooth or somewhat granular on Middlebrook 7H10 agar.

Physiology

• Growth on Löwenstein-Jensen medium or on Middlebrook 7H10 agar at 37 °C, (temperature range 25 °C-40 °C), within 7 or more days.
• Does not grow in the presence of ethambutol or isoniazid.

Differential characteristics

• Closely related to M. kansasii
• M. gastri and M. kansasii share an identical 16S rDNA sequence. Species differentiation is possible by differences in the ITS and hsp65 sequences.
• M. kansasii produces a photochromogenic yellow pigment.
• AccuProbes for M. kansasii are negative.

Pathogenesis

• Casual resident of human stomachs, but not considered a cause of disease.
• Biosafety level 1

Type strain

• First isolated from human gastric specimen. Also found in soil.

Strain ATCC 15754 = CCUG 20995 = CIP 104530 = DSM 43505 = JCM 12407.