Phylum Actinobacteria, Class Actinobacteria, Order Actinomycetales, Suborder Corynebacterineae, Family Mycobacteriaceae, Genus
Mycobacterium, Mycobacterium gadium Casal and Calero 1974.
Acid–alcohol-fast, short rods. Gram-positive.
Colonies on Lowenstein-Jensen medium are small, yellow, butyrous, and spherical
after incubation for 3-4 days. Scotochromogenic pigmentation increases slightly on
exposure to light. Colonies become dry, rugged, and flat in older cultures.
The temperature range for growth is 25-37 ºC; does not grow at 42 or 45 ºC. Can grow
in 5% NaCl media. No growth on MacConkey agar without crystal violet.
Isolated from sputum of a patient in whom an Mycobacterium tuberculosis infection was later diagnosed.
Susceptible to hydroxylamine (500 μg/ml), isoniazid (1 μg/ml), ethambutol (5 μg/ml), streptomycin, cycloserine, viomycin, kanamycin,
and capreomycin. Resistant to ethionamide and rifampicin (partially).
Considered to be non-pathogenic to humans.
Experimental infection: intraperitoneal injection of large numbers of the organism into guinea pigs and mice produced local
lymphadenopathy in 2 weeks, with some dissemination into nearby organs, but this process resolved in 8 weeks.
- John G. Magee and Alan C. Ward 2012. Family III. Mycobacteriaceae Chester 1897, 63AL in Bergey’s Manual of Systematic
Bacteriology, Volume Five The Actinobacteria, Part A, Michael Goodfellow & al. (editors), 312-375.
- Schroder KH, Naumann L, Kroppenstedt RM, Reischl U. Mycobacterium hassiacum sp. nov., a new rapidly growing thermophilic
mycobacterium. Int J Syst Bacteriol 1997; 47:86-91.
- Casal M, Calero JR. Mycobacterium gadium sp. nov. a new species of rapid-growing scotochromogenic mycobacteria. Tubercle
- Luquin M, Ausina V, Vincent-Levy-Frebault V, Laneelle MA, Belda F, Garcia-Barcelo M, Prats G, Daffe M. Mycobacterium brumae
sp. nov., a rapidly growing, nonphotochromogenic mycobacterium. Int. J. Syst. Bacteriol. 1993; 43:405-413.
- Vuorio R, Andersson MA, Rainey FA, Kroppenstedt RM, Kampfer P, Busse HJ, Viljanen M, Salkinoja-Salonen M. A new rapidly
growing mycobacterial species, Mycobacterium murale sp. nov., isolated from the indoor walls of a children's day care centre. Int
J Syst Bacteriol 1999; 49:25-35.
Positive results for acid phosphatase, catalase, heat-stable catalase (68 ºC), beta-galactosidase, nitrate reduction, Tween 80
hydrolysis (10 days),and urease.
Can utilize as sole carbon source acetate, formiate, succinate and lactate.
Acid is formed from mannose, glucose, fructose, and sorbitol.
Negative results for arylsulfatase (3 and 7 days), semiquantitative catalase test, iron uptake, niacin accumulation, neutral red,
allantoinase, acetamidase, benzamidase, isonicotinamidase, nicotinamidase, malonamidase, pyrazinamidase, and succinamidase.
No acid production from L-arabinose, adonitol, galactose, D-mannitol, maltose, L-rhamnose, raffinose, sucrose, trehalose, and
No utilization as sole carbon source of benzoate, citrate, malate, pyruvate, fumarate, malonate, oxalate, and tartrate.
(c) Costin Stoica