FAMILY IV. ENTEROBACTERIACEAE 



347 



The t}'pe species is Paracolobaclrum aerogenoides Borman et al. 



Key to the species of genus Paracolobactrum. 



I. Acetylmethylcarbinol produced. 



1. Paracolobactrum aerogenoides. 

 II. Acetylmethylcarbinol not produced. 



A. Ammonium citrate utilized as a sole source of carbon. 



1. Gelatin not liquefied. 



2. Paracolobactrum intermedium. 



2. Gelatin slowly liquefied. 



3. Paracolobactrum arizonae. 



B. Ammonium citrate not utilized as a sole source of carbon. 



4. Paracolobactrum coliforme. 



1. Paracolobactrum aerogenoides Bor- 

 man et al., 1944. (Para-aerogenes, Stuart, 

 Wheeler, Rustigian and Zimmerman, Jour. 

 Bact., 45, 1943, 117; Borman, Stuart and 

 Wheeler, Jour. Bact., 48, 1944, 361.) 



a.e.ro.ge.no.i'des. M.L. adj. aerogenes 

 gas-producing, a specific epithet; Gr. noun 

 eidus resembling, like; M.L. adj. aeroge- 

 noides (Aerobacter) aerogenes-like. 



Characters as for Aerobacter aerogenes 

 Beijerinck and Aerobacter cloacae Bergey et 

 al. except for consistently delayed fermenta- 

 tion of lactose. 



Primarily non-pathogenic. 



Comments: M0ller (Acta Path, et Micro- 

 biol. Scand., 35, 1954, 262 and 272) has named 

 the non-gelatin-liquefying, Aerobacter aero- 

 genes-like paracolons the Hafnia Group, 

 type species Hafnia alvei M0ller {ibid., 272). 

 The organisms in the Hafnia Group are 

 motile at 22° becoming less motile at 36° and 

 non-motile at 38° C. 



Source : Isolated from cases of human gas- 

 troenteritis. 



Habitat: Found in surface water, soil, 

 grains and the intestinal tracts of animals, 

 including man. 



2. Paracolobactrum intermedium Bor- 

 man et al., 1944. (Para-freundii, Stuart, 

 Wheeler, Rustigian and Zimmerman, Jour. 

 Bact., 45, 1943, 117; Borman, Stuart and 

 Wheeler, Jour. Bact., 48, 1944, 361.) 



in.ter.me'di.um. L. adj. intermedius 

 intermediate. 



Characters as for Escherichia freundii 

 Yale and Escherichia intermedia Vaughn and 

 Levine except for consistently delayed fer- 

 mentation of lactose. 



Relationships to other species: The 

 Ballerup Group (Bruner, Edwards and Hop- 

 son, Jour. Inf. Dis., 85, 1949, 290) and the 

 Bethesda Group (Edwards, West and 

 Bruner, Jour. Bact., 55, 1948, 712) have 

 been combined by recent investigators 

 (West and Edwards, U. S. Dept. Health, 

 Education and Welfare Monograph, No. 22, 

 1954, 34; Kauffmann, Enter obacteriaceae. 

 Ejnar Munksgaard, Copenhagen, 1954, 210). 

 While these workers recognize the combined 

 groups as being identical with Paracolo- 

 bactrum intermedium Borman et al., they do 

 not distinguish between them and Escher- 

 ichia freundii Yale. 



Source: Isolated from cases of human 

 gastroenteritis. 



Habitat: Found in surface water, soil, 

 grains and the intestinal tracts of animals, 

 including man. 



3. Paracolobactrum arizonae (Kauff- 

 mann, 1940) Borman, comb. nov. {Salmonella 

 sp., Dar es salaam Type var. from Arizona, 

 Caldwell and Ryerson, Jour. Inf. Dis., 66, 

 1939, 245 ; Salmonella arizona (sic) Kauffmann, 

 Acta Path, et Microbiol. Scand., 17, 1940, 

 or 19, 1942; Arizona culture, Edwards, 

 Cherry and Bruner, Jour. Inf. Dis., 73, 1943, 

 236; Arizona Group, Edwards, Jour. Bact., 

 49, 1945, 513.) 



a.ri.zo'nae. M.L. noun Arizona Arizona; 

 M.L. gen. noun arizonae of Arizona. 



Rods. Motile by means of peritrichous 

 flagella. Gram-negative. 



Gelatin: Slow liquefaction. 



Potassium cyanide medium: No growth 

 (exceptions are rare) . 



Indole not produced. 



