FAMILY I. MYCOBACTERIACEAE 



701 



Petragnani's medium: Primaiy growth 

 visible in 4 weeks as minute, transparent, 

 dome-shaped colonies; in older cultures 

 colonies are low convex to flat with irregular 

 outline and rough surface, lemon to mus- 

 tard-yellow. 



Dorset's egg medium: Scanty growth, the 

 colonies resembling those on Petragnani's 

 medium, but there is little or no pigment. 



Glycerol broth: Growth onh' when colony 

 fragments are used as the inoculum, form- 

 ing white, irregular, floating balls; no pellicle 

 formed. 



Glycerol: Low concentrations in most 

 media enhance growth, especially in the 

 later stages of growth. 



Optimum temperature, between 30° and 

 33° C. Very limited growth at 25° and 37°, 

 and no growth at 41° C. 



Pathogenicity: Causes skin ulcers in man 

 which are characterized by indolent exten- 

 sion from areas of inconspicuous induration 

 to involve large areas. Rats and mice are 

 infected experimental!}' ; guinea pigs, rab- 

 bits, fowls and lizards are resistant. E.xperi- 

 mentally inoculated rats develop hemorrha- 

 gic necrotic lesions surrounded bj' zones of 

 cellular accumulations consisting of leuco- 

 cytes, lymphocytes and macrophages. There 

 are no giant cells. The necrotic and cellular 

 zones show large clumps of acid-fast bacilli 

 in the extra-cellular spaces and in macro- 

 phages. 



Antigenic structure: In complement fixa- 

 tion tests with sera of rabbits immunized 

 with human, bovine and murine types of 

 tubercle bacilli, Mycobacterium ranae and 

 M. phlei, the heat-killed, washed bacilli 

 serving as antigens, M. ulcerans was found to 

 be antigenicallj' distinct from the other 

 pathogenic species of Mycobacterium tested. 

 This conclusion was supported by skin sen- 

 sitivity reactions in guinea pigs (Fenner 

 and Leach, op. cit., 30, 1952, 1; and Fenner, 

 op. cit., 30, 1952, 11). 



Distinctive characters: Acid-fast bacilli; 

 grows at 33° but not at 37° C; produces 

 necrotic and ulcerative lesions in man, rats 

 and mice without giant-cell formation; 

 antigenically distinct from the other 

 pathogenic species of Mycobacterium. 



Source: Isolated from ulcerative skin 

 infections in man. 



Habitat : The apparent cause of skin ulcers 

 in man. Transmissible to rats and mice. 



8. Mycobacterium tuberculosis (Zopf, 

 1883) Lehmann and Neumann, 1896. 

 (Tuberkelbacillen, Koch, Berl. klin. Wochn- 

 schr., 19, 1882, 225; Bacterium tuberculosis 

 Zopf, Die Spaltpilze, 1 Aufl., 1883, 67; Tu- 

 berkelbacillen, Koch, Mitteil. a. d. kaiserl. 

 Gesundheitsamte, 2, 1884, 6; Bacillus tuber- 

 culosis Schroeter, in Cohn, Kryptogamen- 

 Flora V. Schlesien, 3, 1886, 164; Human 

 tubercle bacilli, Th. Smith, Trans. Assoc. 

 Am. Phys., 11, 1896, 75; Lehmann and Neu- 

 mann, Bakt. Diag., 1 Aufl., 2, 1896, 363; 

 Mycobacteritim txibercxdosis tj^pus humanus 

 Lehmann and Neumann, ibid., 4 Aufl., 2, 

 1907, 550; Mycobacterium tuberculosis var. 

 hominis Bergey et al.. Manual, 4th ed., 

 1934, 536.) 



tu.ber.cu.lo'sis. L. dim. noun tuberculum 

 a small swelling, tubercle; Gr. suffix -osis 

 characterized by; M.L. fern. gen. n. tubercu- 

 losis of tuberculosis. 



Common name: Human tubercle bacillus. 



Original description supplemented by 

 material taken from Topley and Wilson 

 (Princip. of Bact. and Immun., London, 

 2nded., 1936,315). 



Rods, ranging in size from 0.3 to 0.6 by 

 0.5 to 4.0 microns, straight or slightly 

 curved, occurring singly and in occasional 

 threads. Sometimes swollen, clavate or even 

 branched. Stain uniformly or irregularly, 

 showing banded or beaded forms. Acid-fast 

 and acid -alcohol -fast. Gram-positive. 

 Growth in all media is slow, requiring 

 several weeks for development. 



This bacterium contains mycolic acid 

 (Stodola, Lesuk and Anderson, Jour. Biol. 

 Chem., 1S6, 1938, 505). The acid-fast mycolic 

 acid combines more firmly with carbol- 

 auramin than with carbol-fuchsin, and this 

 apparently accounts for the increased sensi- 

 tivity of fluorescence microscopy for this 

 bacterium (Richards, Science, 93, 1941, 190; 

 Richards, Kline and Leach, Amer. Rev. 

 Tuberc, U, 1941, 255). 



Glycerol agar colonies: Raised, thick. 



