432 DESCRIPTION OF SOME SPECIES OF MILK BACTERIA 



This organism can develop in 

 butter and cheese, which then show 

 blue or greenish -blue patches in 

 which the rods described are found 

 in abundance. 



The bacillus isolated from blue 

 milk by Zangemeister and described 

 by him under the name of B. cyano- 

 fluorescens, appears to be simply a 

 variety of the B. syncyaneus. It 

 only differs in some minute varia- 

 tions of form, the aspect of the 

 colonies and the production of 

 pigment. 



Non-pathogenic — Even when 

 inoculated in large quantities. 



BACIIiIiUS SYNXANTHUS 



(B. of yellow milk). 



Source and habitat — Milk. 



Morphology — Short thin rods. 



Staining reaction — Ordinary stains, 

 and by Gram's method. 



Motility — ^Actively motile. 



Biology : cultural characters {includ- 

 ing biochemical features) — Produces 

 a yellow pigment, readily soluble 

 in water, not in ether and alcohol ; 

 decolorised by acids, but returns 

 on treating with alkalis. 



Bouillon — Uniform turbidity and 

 a pellicle. 



Gelatine plates and tubes — 

 Luxuriant yellow-grey growths ; 

 no liquefaction. 



Milk — Iscolouredabrightyellow, 

 the casein is dissolved, and the 

 milk becomes alkaline. 

 Non-pathogenic. 



baciIjIjUS tuberculosis op 



KOCH. 



Source and habitat— Human sputum, 

 and discharges from tubercular 

 patients ; dust, milk, etc. 



Morphology — Slender, slightly bent 

 bacilli, with pointed ends ; threads 

 and true branched forms occur in 

 sputum, and particularly in old 



cultures. They have also been 

 obtained on acid potatoes. Club- 

 shaped forms have also been des- 

 cribed. 1-5 to 4 M long by 0-4 /j. 

 broad. Short in tissues, longer in 

 milk ; solitary, or in twos or threes, 

 often circumflex arrangement ; in 

 groups and bundles ; discrete in 

 human tissues and discharges ; in 

 colonies in animal tissues and dis- 

 charges. 

 Staining reaction — Acid-fast ; Ziehl- 

 Neelsen method ; also by Gram's 

 method. 

 Flagellaj motility j spore formation — 

 Unstained vacuoles and granules 

 often occur, but they are not true 

 spores. There are no flagella in 

 ordinary forms and no motility. 

 The capsule stains. 

 Biology : cultural characters {includ- 

 ing biochemical features) — Growth 

 occurs from 22°-42° C. It is best at 

 37° C. 



Bouillon — Growth occurs in 7 

 or 8 days if glycerine added ; 

 from glycerinated cultures the 

 bacillus may be removed and 

 grown in ordinary bouillon. Klein 

 obtained growth in bouillon to 

 which white of ^g^, had been added. 

 Pellicle may be produced. 



Glycerine-agar — Minute crumb- 

 like colonies, irregular in form, 

 whitish-yellow in colour, elevated, 

 sinuate. Later the entire growth 

 becomes brownish in colour. The 

 appearance is not unlike miniature 

 mountain ranges. Sometimes the 

 growth is dry, in other cases moist. 1 

 Growth slow, commences 6 to 12 | 

 days ; not unlike lichen. 



Potato — Small, crumb-like, 

 yellow, friable masses ; dull and 

 withoutmoistness or lustre. Growth 

 marked in about 2 to 3 weeks. 

 Best if potato kept moist. 



Blood serum — A slight growth in 

 the form of light - coloured, dry, j 



