888 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



1899, 409.) From Latin lac, lactis, milk 

 and colo, to dwell ; hence, a milk dweller. 



From the fact that Lehmann and Neu- 

 mann {loc. cit., 411) refer to the binomial 

 Bacillus friburgensis Korn, it is evident 

 that the species name Jrihurgensis (see 

 Appendix) published the same year 

 (1899) has priority over the species name 

 lacticola. However, since it has never 

 been used with the broad meaning given 

 Mycobacterium lacticola by Lehmann and 

 Neumann in the original description, it 

 is not substituted for the more com- 

 monly used Mycobacterium lacticola in 

 this edition of the Manual. 



Description from Lehmann and Neu- 

 mann {loc. cit) and Jensen (Proc. Linnean 

 Soc. of New So. Wales, 59, 1934. 19). 



Slender rods : 0.5 to 0.7 by 2 to 8 microns 

 in young cultures, in older cultures the 

 rods are shorter and frequently coccoid 

 in shape. Curved and irregular forms 

 occur occasionally. Branched forms, 

 if they occur, are ver\- rare. Staining 

 is generally uniform but slight beading 

 occurs occasionally. Strongly acid-fast 

 except organisms from glucose-contain- 

 ing media which are sometimes only 

 faintly acid-fast. Gram-positive. 



Gelatin colonies: Similar to those on 

 agar. 



Gelatin stab: Filiform growth in stal). 

 No liquefaction. 



Agar colonies : Convex, glistening, with 

 entire margins, at first smooth but after 

 10 to 14 days growth folded or wrinkled. 

 Opaque, at first white, after 2 or 3 days 

 growth becomes yellow. 



Glucose agar : Similar to agar but more 

 rapid growth and less intensely pig- 

 mented. 



Glycerol agar slants : Spreading, moist, 

 wrinkled, pale cream-colored to yellow. 



Nutrient broth: Diffuse growth, later 

 with yellowish pellicle. 



Litmus milk: Small white granules of 

 growth at the surface, later a dry yellow- 

 ish pellicle. After some weeks' growth 

 the milk becomes alkaline and clear. 

 No coagulation. 



Dorset's egg medium: As on glycerol 

 agar. 



Coagulated serum : As qp glycerol agar. 



Potato: Spreading, raised, wrinkled 

 growth, pale yellow to orange. 



Long's medium lacking glycerol : No 

 growth. Long's medium with 5 per cent 

 glycerol : Acid formed. (Thomson, 

 Amer. Rev. Tub., 26, 1932, 162.) 



Indole not formed. 



Nitrates: Reduced, doubtful (Jensen). 



Carbohydrates : Glucose, fructose, arab- 

 inose and galactose are utilized ; lactose 

 is not utilized ; sucrose is not utilized by 

 3 strains, utilized by 1 strain {Mycobac- 

 teriiwi friburgensis) (Merrill, Jour. Bact., 

 20, 1930, 235). Sorbitol, arabinose, galac- 

 tose, trehalose, mannitol and fructose are 

 utilized ; sucrose is not utilized (Gordon, 

 Jour. Bact., 34, 1937, 617). 



Optimum temperature 37°C, maximum 

 temperature for growth 52°C, minimum 

 15° to 18°C. Fails to survive 60°C for 

 1 hour, grows at 47°C (Gordon, Jour. 

 Bact., 34, 1937, 617; Gordon andHagan, 

 Jour. Bact., 36, 1938, 39). 



Optimum pH 6.8 to 7.2. Limits for 

 growth 4.5 to 10.0. 



Distinctive characters: Saprophytic 

 acid-fast organism. Grows rapidly on 

 most media, develops a yellow or orange 

 pigmentation after 3 to 4 days growth. 

 Fails to grow on Long's medium lacking 

 glycerol and produces acid when glycerol 

 is present. Fails to survive 60°C for an 

 hour, grows at temperatures as high as 

 47°C. 



Variation : Lehmann and Neumann 

 (Bakt. Diag., 2 Aufi., 2, 1899, 408) and 

 Haag (Cent. f. Bakt., II Abt., 71, 1927, 1) 

 describe three forms : a flat smooth form, 

 a moist, slimy, smooth form and a dry, 

 friable perrugose form. The two former 

 correspond with S and the latter with R 

 types described by Bynoe as characteris- 

 tic of Mycobacterium stercoris, Myco- 

 bacterium berolinensis, Mycobacterium 

 butyricum and Mycobacterium graminis 

 which in turn correspond with S and R 

 types of other members of the genus. 

 Schwabacher (Spec. Rep. Ser. Med. Res. 



