Phylum Actinobacteria, Class Actinobacteria, Order Actinomycetales, Suborder Corynebacterineae, Family Mycobacteriaceae, Genus
Mycobacterium, Mycobacterium farcinogenes Chamoiseau 1973.
Old synonym: "Mycobacterium farcinogenes subsp. tchadense" .
Strongly acid-alcohol-fast rods. Produce short or long, bent, and branched filaments
grouped in clumps or in a tangled lacy network, not fragmenting into bacillary forms.
Cords are not formed. Gram-positive.
Colonies on Lowenstein-Jensen medium are honey yellow, rough and convoluted,
firmly attached to the medium, and surrounded by an iridescent halo. In contrast,
growth on most agar-based media can be seen as small isolated pale halos, which
coalesce to form wheat colored (non-chromogenic), rough convoluted, raised,
wrinkled growth. In broth medium such as tryptose broth with serum, a thick rough dry
growth develops with a whitish surface veil, but the broth remains clear. Growth
occurs in 15-20 days in liquid or on solid medium. Grows at 25-37 ºC, but not at 40 or
45 ºC. No growth on MacConkey agar or on media supplemented with 5% (w/v) NaCl.
Isolated from lesions of farcy in African bovines (Zebu cows). Isolated from sputum samples of pastoralists of the Hamer Woreda
tribe in southern parts of Ethiopia; and from a person with failed hip implant.
Resistant to thiophen-2-carboxylic acid hydrazide (TCH), ethambutol (2 μg/ml) (most strains), isoniazid (1 μg/ml), rifampin (32 μg/ml)
(many strains), and streptomycin (8 μg/ml). Susceptible to capreomycin and dapsone.
Produce bovine farcy; do not affect other domestic or non-domestic animals. Mycobacterium farcinogenes causes the disease in East
and Central Africa and Mycobacterium senegalense in West Africa.
Isolated from humans with clinical signs of tuberculosis.
- subcutaneous inoculation of the organism into guinea pigs produces draining abscesses after 8 days, which heal slowly. Abscesses
are seen in the testes, seminal vesicles, or vagina in 6-7 days after intraperitoneal injection; most animals die after prolonged infection.
- a zebu calf inoculated with M. farcinogenes died after 84 days with miliary lung lesions (evenly distributed caseous pulmonary nodules
about 2 mm in diameter).
- 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.
- Hamid, M. E. (2012). Epidemiology, pathology, immunology and diagnosis of bovine farcy: A review. Preventive Veterinary
Medicine, 105(1-2), 1–9. doi:10.1016/j.prevetmed.2012.01.004.
- Stephen Berger 2019. GIDEON Guide to Medically Important Bacteria, eBook.
- Ridell, M., and M. Goodfellow. 1983. Numerical classification of Mycobacterium farcinogenes, Mycobacterium senegalense and
related taxa. J. Gen. Microbiol. 129:599-611.
- El-Sanousi, S. M., and M. A. M. Salih. 1979. Miliary bovine farcy experimentally induced in a zebu calf. Vet. Pathol. 16:372-373.
- Chamoiseau G. Etiology of farcy in African bovines: nomenclature of the causal organisms Mycobacterium farcinogenes
Chamoiseau and Mycobacterium senegalense (Chamoiseau) comb. nov. International Journal of Systematic Bacteriology 1979;
- Levy-Frebault V, Rafidinarivo E, Prome JC, Grandry J, Boisvert H, David HL. Mycobacterium fallax sp. nov. Int. J. Syst. Bacteriol.
- Shojaei H, Daley C, Gitti Z, Hashemi A, Heidarieh P, Moore ER, Naser AD, Russo C, van Ingen J, Tortoli E. Mycobacterium
iranicum sp. nov., a rapidly growing scotochromogenic species isolated from clinical specimens on three different continents. Int
J Syst Evol Microbiol 2013; 63:1383-1389.
Positive results for catalase (contradictory reports), semiquantitative catalase test, thermostable catalase (68 ºC), nitrate reduction,
acetamidase, allantoinase, benzamidase, formamidase, nicotinamidase, and isonicotinamidase.
Can utilize citrate, benzoate, and pyruvate.
Negative results for arylsulphatase (10 days), catalase, iron uptake, neutral red test, niacin accumulation, tellurite reduction, and
Tween hydrolysis. No hydrolysis of gelatin, casein, tyrosine, hypoxanthine, or xanthine. No utilization of inositol, sorbitol or malonate.
Variable results for pyrazinamidase, salicylamidase, and urease.
(c) Costin Stoica