396 THE COLI—CLOAC.E— PROTEUS GROUP 
Urea is actively decomposed, ammonia and carbon dioxide being liber- 
ated. ^ The addition of f>lucose is said to prevent the liberation of 
ammonia and carbon dioxide.'- 
{h) Enzymes. —B. protens prodnces a sohible proteolytic enzyme 
in protein media containing no ntilizable sugars, which liciuefies egg 
albumen, fibrin, blood serum, and gelatin. It is tryptic, rather than 
peptic in character.^ This enzyme"* is not produced when ntilizable 
sugars are present in the medium. No other enzymes are known. 
{(■) Toxins.— A soluble toxin has not been demonstrated in cultures 
of B. protens. At one time "sepsin" was supposed to be an import- 
ant factor in "jjtomain poisoning." This substance is produced in 
but minute amounts by proteus bacilli, however, and no importance is 
now attached to it. The nature of the poisonous substance produced by 
B. proteus is unknown. 
Pathogenesis. — Several types of disease have been attributed to 
members of the proteus group. Meat poisoning and ptomain poison- 
ing epidemics caused by eating meats decomposed by the organisms 
have been reported by Levy,* Wesenberg,*^ Silberschmidt^ and Pfuhl.^ 
Dieudonne'^ has described an epidemic which originated in a potato 
salad from which proteus bacilli were isolated. B. proteus is one of 
the very feW' bacteria which will cause cystitis when it is injected 
into the urinary bladder. Cystitis in man is frequently caused by 
B. proteus.^'' Pyelonephritis, frequently of a very purulent type, and 
abscesses are occasionally caused by members of the group. The 
organisms do not as a rule grow in normal tissues, but they grow 
readily in necrotic tissues, forming much pus which has a fetid odor. 
Middle ear infections, characterized by very foul-smelling pus, have 
been reported. 
B. proteus fluorescens, an organism exhibiting many characteristics 
of the proteus group, has been isolated from several cases of A' eil's 
disease (infectious jaundice) by Jaeger,^* Conradiand Vogt,*"^and Briin- 
ing.^^ It is now definitely established that the organism has no etiologi- 
cal relationship to the disease.*'* Bar and Renon*^ isolated a similar 
bacillus from a case of jaundice in the new-born. Booker**^ has isolated 
B. proteus from the feces of a large number of cases of acute summer 
diarrhea in children. It would apjiear from his studies that the 
organisms played a prominent part in the causation of certain types 
1 Schnitzler: Centralbl. f. Bakteriol., 1893, 13, 68. 
2 Brodmeier: Centralbl. f. Bakteriol., 1895, 18, 380. 
3 Kendall and Keith: Jour. Infec. Dis., 1926, 38, 193. 
* Kendall, Cheetham and Hamilton: Jour. Infec. Dis., 1922, 30, 251. 
'■> Arch. f. exp. Path. u. Pharm., 1895, 34, 342. « Ztschr. f. Hyg., 1898, 28, 484. 
' Ibid., 1899, 30, 328. « Ibid., 1900, 35, 265. 
9 Mlinchen. med. Wchnschr.. 1003, 50, 2282. 
" Meyerhof: Centralbl. f. Bakteriol., 1898, 24, 18, 55, 148. 
'1 Ztschr. f. Hyg., 1892, 12, 525. '^ ibid., 1901, 37, 283. 
" Deutsch. med. Wchnschr., 1904, 30, 1269. 
'* Infectious jaundice is the result of infection with Leptospira icterohoemorrhagi£e, 
(See page 596). 
''' Semaine med., 1895, p. 234. Johns Hopkins Hosp. Rep., vol. 6. 
