cells produce lepromin reactions in lepro- leprosy-like acid-fast bacilli that have not matous humans. The bacilli from lesions are yet been cultivated on artificial media, not bound together in clumps, rounded Source: An endemic disease of rats in masses and palisades as in human lesions. various parts of the world, having been For further details, see review by Lowe found in Odessa, Berlin, London, New (Internat. Jour. Leprosy, 5, 1937, 310 and South Wales, Hawaii, San Francisco and 463). elsewhere. Comment: Nodular diseases of the skin Habitat: The natural disease occurs of other animals have been described, e.g. a chiefly in the skin and lymph nodes, caus- disease of the buffalo in India and of the ing induration, alopecia (loss of hair) and frog in South America, which are caused by eventually ulceration. Genus II. Mycococcus Krassilnikov, 1938* (Krassilnikov, Microbiologia (Russian), 7, Part 1, 1938, 335; also see Ray Fungi and Related Organisms, Izd. Akad. Nauk, U.S.S.R., Moskau, 1938, 121, Guide to the Actinomycetes, Izd. Akad. Nauk, U.S.S.R., Moskau, 1941, 122, and Guide to the Bacteria and Actinomycetes, Izd. Akad. Nauk, U.S.S.R., Moskau, 1949, 198; not Mycococcus Bokor, Arch. f. Mikrobiol., /, 1930, 1.) My'co. coccus. Gr. noun myces a fungus; Gr. noun coccus a berry, a sphere; M.L. mas.n. Mycococcus coccus-shaped fungus. Cells generally spherical, occurring singly, in short chains or in clumps; rod-shaped cells also occur, particularly in potato and liquid media. The spherical cells are quite variable in size and shape, the smaller cocci measuring 0.2 to 0.5 micron in diameter, and the larger cells (involution forms) measuring 0.7 to 1.0 micron in diameter; occasional cells are angu- lar or ameboid in shape. The length of the rod-shaped cells ordinarily does not exceed twice the width. Multiplication is by fission, constriction or bud formation. Resting cells, which are produced from vegetative, coccus-like cells, germinate in a manner analogous to that of the spores of the Actinomycetes, forming one to three germ tubes on their surface. Not acid-fast. Gram-positive. Grow well on ordinary culture media. Gross appearance of colo- nies similar to those of the genus Mycobacterium; red, yellow-green or orange pigments are produced. Aerobic. Found widely distributed in soils. The type species is Mycococcus albus Krassilnikov. Key to the species of genus Mycococcus.f I. Non-chromogenic. A. Proteolytic property strong. Milk coagulated and peptonized. 1. Mycococcus albus. B. Proteolytic property weak. 1. Milk slowly coagulated, becoming slightly alkaline; weakly peptonized. la. Mycococcus albus subsp. albidus. 2. Milk rapidly coagulated, becoming slightly acid; not peptonized. lb. Mycococcus albus subsp. lactis. II. Chromogenic. A. Chromogenesis red, orange or rust. 1. Colonies with dough-like consistency. a. Cells occur singly, in pairs or in chains 3 to 4 microns in length. 2. Mycococcus ruber.
- Prepared by Miss Lois Nellis, Hobart College, Geneva, New York, from a translation
made by Prof. S. A. Waksman, Rutgers University, New Bnmswick, New Jersey, Decem- ber, 1954. t Key based on a table by Krassilnikov, Guide to the Actinomycetes, Izd. Akad. Nauk, U.S.S.R., Moskau, 1941, 123.
