COMPREHEXSIVE KEY 1021 



or filamentous; may reach 100 to 150 microns in length; homogeneous in young 

 cultures but become granulated, beaded and swollen in old cultures and tend to frag- 

 ment into rods and cocci; large spherical swellings packed with granules common; 

 cholesterol globules appear among the growth; only rods and short filaments appear 

 in pathological material; non-branching; non-acid fast; colonies on ascitic agar 

 1 to 2.5 mm in 3 days, circular, low convex, colorless; L-phase variants are common; 

 highly virulent for mice causing polyarthritis. Causes rat-bite or Haverhill fever 



in man Streptobacillus p. 451 



{S. moniliformis) 

 Not as above: grow well on media without blood or .serum 66 



66. Colonies colorless 67 



Colonies yellow 70 



67. Organisms grow in 0.5 per cent peptone containing filter paper, causing the latter to 



disintegrate; gelatin liquefied; nitrite produced from nitrate; starch hydrolyzed 



Cellulomonas p. 601 

 Not as above 68 



68. Lactose fermented in two days ' 69 



Lactose fermentation delayed; enteric pathogens Shigella p. 384 



(Shigella Group, Rome, 1953, slow lactose-fermenters) 



69. Encapsulated cells; pathogenic Klebsiella p. 344 



Not as above Achromobacter p. 300 



70. Curved rods which transform completely into coccoid forms during growth of the 

 colony. Rods elongate and divide. At the point of division the rods grow out at an 

 angle to the original axis and divide again at the angle when the cell has doubled 

 its length. This process continues until a colony is formed. Ultimately the rods trans- 

 form completely into cocci Arthrobacter p. 605 



Note: The emphasis lies on the final transformation into cocci. Some authori- 

 ties may consider that limited true branching may occur. If this is admitted 

 the dividing line between Arthrobacter and Nocardia becomes very slim. The 

 author's observations of Arthrobacter globiforme fit the above statement, and 

 it is suggested that these criteria be adopted, true branching forms which 

 later disintegrate being assigned to Nocardia. 



Not as above; starch hydrolyzed Flavobacterium p. 309 



In addition to the above, the following species, two of them plant pathogens, ter- 

 minate at this point: Pseudomonas iridescens, Corynebacterium agropyri and Bacte- 

 rium stewartii. 



71. Non-motile 72 



Motile 103 



72. Acid and gas from glucose 73 



Acid but no gas from glucose 77 



No acid or gas from glucose 85 



73. Only a small amount of gas from glucose; causes dysentery in man; agglutinated by 



polyvalent antiserum to Shigella jlexneri Shigella p. 384 



(Newcastle strain) 

 Organisms which cause bacillary white diarrhoea of chickens; agglutinated with 



Salmonella group D "O" antiserum Salmonella p. 368 



(S. puUorum) 

 Not as above 74 



74. Bioluminescent on 3 per cent salt agar, especially with a fish base; pleomorphic and 



branching rods on asparagine-sugar media; 2-3-butylene-glj-col produced 



Photobacterium p. 193 

 Not bioluminescent 75 



75. Gelatin liquefied; nitrites produced from nitrates; methyl-red negative; Voges-Pros- 



