VtBRlON SEPTIQVE 539 
Immunity and Immunization. Leclainche and \'allee/ IMarkoff,- and 
Meyer,-' have inununized animals with cultures of ^'ihri()n septique 
and have shown that the sera of these animals will agij;lutinate the 
hemologous strain in high dilution. IVIiss Robertson'* has found that 
at least three serologically specific types of the organism may be recog- 
nized by suitable immune sera.'' These differences, however, are 
probably not to be regarded as establishing species within the type. 
It was found that the injection of impure cultures of Vibrion septique 
did not lead to the formation of potent agglutinating sera.*^ 
Antitoxin.— Antitoxic sera have been obtained from horses immun- 
ized with cultures of the organism. The serum has considerable 
protective powers, but is not very successful in controlling infections 
already established. The antiserum may reach as high a titer as 500 
to 1000 units. ^ 
Pathogenesis. —Vibrion septique is quite variable with respect to its 
pathogenic power; some strains are highly virulent for guinea-pigs 
and rabbits, others are almost devoid of pathogenic powers. Glucose 
broth cultures, or cultures developed in glucose broth and cooked 
meat, from twenty- four to forty-eight hours old, are the best for experi- 
mental purposes. From 0.1 cc. to 0.005 cc, depending upon the strain 
of organism, will frequently kill a guinea-pig within twenty-four hours. 
Rabbits, gram for gram, are somewhat more susceptible than guinea- 
pigs to the same toxin. 
Animals which have been killed by the injection of cultures of the 
Vibrion septique show lesions which are reminiscent of those incited 
by B. welchii. Before death there is a somewhat rapidly developing 
edema, and some gas, as showai by crepitation. The process is fre- 
quently associated with paralysis of the legs, if the amount of toxin 
injected is insufficient to kill the animal promptly. 
At autopsy there is marked edema, and rows of minute gas bubbles 
are frequently seen in the hyperemic tissue.^ The adrenals are greatly 
engorged with blood, and of a dark brown color. The liver, spleen and 
kidneys are usually rather paler than those of normal animals. The 
edema fluid and the peritoneal fluid (which is increased in amount) is 
rich in long filaments which exhibit the characteristic serpentine motion 
under the microscope. Smears from the surface of the parenchima- 
tous organs show the same chains, and, in most instances, pro\ided pure 
cultures have been used, the typical citron and navicular involution 
forms as well. These stain irregularly. Pure cultures may be obtained 
1 Ann. Inst. Pasteur, 1900, 14, 202, 51.3. 
2 Centralbl. f. Bakteriol., orig., 1911, 60, 188. 
' Jour. Infec. Dis., 1915, 17, 458. 
'■ Jour. Pathol, and Bacteriol., 1920, 23, 153. 
^ Attention is redirected to chemical tjiJes of the organism as well as serological t>T3es. 
6 Jour. Pathol, and Bacteriol., 1920, 23, 153. 
^ Raphael and Frasey: Compt. rend. Acad. Sci., 1915, 161, 361. 
« The degree of edema is influenced materially by the time elapsing between the 
injection and the death of the animal. 
