COMPREHENSIVE KEY 1023 



slightl}' in size on further incubation; light brown on potato; Straus reaction pro- 

 duced in guinea pigs; strict parasites causing glanders in man and animals 



Actinobacillus p. J^H 

 {A. mallei) 



Small ovoid coccobacilli arranged singlj^ and in pairs or in small bundles; sometimes 

 pleomorphic; frequently exhibit bipolar staining; colonies on meat infusion agar 

 0.1 to 1.0 mm in diameter in 24 hours at 37° C. ; may increase in size up to 4 to 6 mm 

 in 5 days at 37° C. A slight thin layer or no growth on potato; organisms cause 

 plague in man and rodents or hemorrhagic septicemia in various other animals and 

 in birds Pasteurella p. 395 



Organisms cause actinobacillosis in man and other animals and may also be found in 

 actinomycotic lesions; colonies on agar small, circular, bluish gray, translucent, 

 with a smooth surface and an entire edge, up to 1.5 mm in diameter in 24 hours at 

 37° C. but increase considerably in size on further incubation; on alkaline potato 

 a slight glistening grayish yellow growth is produced Actinobacillus p. J^ll^ 



Not as above 81 



81. 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 transform 



completely into cocci. Colonies yellow or colorless 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 82 



82. Colonies yellow Flavobacterium p. 309 



Colonies colorless 83 



83. Enteric pathogens of man; agglutinate with Shigella antisera Shigella p. 384 



{Shigella Group, Rome, 1953; non-lactose-fermenters) 

 Organisms pathogenic to birds; agglutinate with Salmonella Group D "O" antiserum 



Salmonella p. 368 

 {S. gallinarum) 

 Not as above 84 



84. Organisms cause disintegration of filter paper in 0.5 per cent peptone water 



Cellulonionas p. 601 

 Not as above Achroniobacter p. 300 



85. Soil organisms; 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 transform completely into cocci; colonies yellow or colorless 



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 86 



