BACILLUS CLOACJE 393 
colonies are inoculated into broth and incubated to obtain sufficient 
organisms for their identification by cultural methods. 
Cultural Identification. —A motile, (iram-negative bacillus which pro- 
duces gas in glucose, lactose and mannitol (optionally in saccharose), 
which coagulates but does not peptonize milk, does not liquefy gelatin, 
and is without action upon starches is a member of the B. coli group. 
BACILLUS CLOACA. 
Bacillus cloacie was isolated from sewage and polluted water by 
Jordan.^ The organism appears to be relatively abundant some years 
and comparatively uncommon other years. When it is abundant in 
sewage it is found occasionally in the intestinal tract of man. 
Morphology.— The bacillus is of moderate size, measuring from O.C) 
to O.S micron in diameter and from 1 to 2 microns in length. It 
occurs singly or in pairs, uncommonly in short chains. Young cultures 
exliibit motility, and the organisms possess peritrichic flagella. No 
spores or capsules have been demonstrated. Ordinary anilin dyes 
color the bacilli readily, and the\' are Gram-negative. 
Isolation and Culture.— The colonies on agar plates after eighteen 
hours' incubation are round, clear and colorless, anfl measure from 
1 to 3 mm. in diameter. There is nothing distinctive in the appear- 
ance of the growths. 
Products of Growth. — (a) Chemical. IwdoX, phenol, hydrogen sul- 
phide and ammonia are produced in sugar-free broth. The ammonia 
production is greater than that characteristic of B. coli and less than 
that ordinarily produced by B. proteus.' Acid and gas are produced 
in glucose, lactose, saccharose, and mannitol broths. The gas ratio 
is somewhat variable, but distinctive; the proportion of carbon dioxide 
to hydrogen is greater than that produced by other closely-related 
bacteria.^ The action of the organism upon lactose is slow, and less 
gas is produced from this sugar. The amount of gas produced from 
glucose and saccharose is greater than that produced by other aero- 
genic members of the paratyphoid-proteus group. B. cloacae forms 
but little acid from the fermentation of sugars, and after one to three 
days the reaction, even in sugar broth, becomes alkaline, due to the 
exliaustion of the sugar and the subsequent decomposition of the 
protein constituents of the broth."* Indol and other products of putre- 
faction are formed as soon as the sugar is exhausted. 
Milk is coagulated and slowly peptonized. Freshly isolated cultures 
usually liquefy gelatin, but this property is lost after prolonged artifi- 
cial cultivation. 
The organism is ordinarily non-pathogenic for man. 
' Annual Report of Massachusetts State Board of Health, 1890, p. 836. 
2 Kendall, Day and Walker: Jour. Am. Chem. Soc, 1913, 35, 1230. 
3 H : CO2 = i - i Theobald Smith: Fermentation Tube, 1893, p. 215. 
^ Kendall, Day and Walker: Loc. eit. 
