PATHOGENIC AEROBIC BACILLI 



one cubic centimetre or more of a culture in bouillon usually cause 

 the death of the animal in from twelve to thirty-six hours. An ex- 

 tensive inflammatory oedema and purulent infiltration of the tissues 

 result from subcutaneous inoculations, and a sero-fibrinous or puru- 

 lent peritonitis is induced by the introduction of the bacillus into the 

 peritoneal cavity. The bacillus is found in the serous or purulent 

 fluid in the subcutaneous tissues or abdominal cavity, and also in the 

 blood and various organs, from which it can be recovered in pure 

 cultures, although not present in great numbers, as is the case in 

 the various forms of septicaemia heretofore described. When smaller 

 amounts are injected subcutaneously the animal usually recovers 

 after the formation of a local abscess, and it is subsequently immune 

 when inoculated with doses which would be fatal to an unprotected 

 animal. Immunity may also be secured by the injection of a con- 

 siderable quantity of a sterilized culture. Bouchard has also pro- 

 duced immunity in rabbits by injecting into them the filtered urine 

 of other rabbits which had been inoculated with a virulent culture of 

 the bacillus. It has been shown by Bouchard, and by Charrin and 

 Guignard, that in rabbits which have been inoculated with a culture 

 of the anthrax bacillus a fatal result may be prevented by soon after 

 inoculating the same animals with a pure culture of the Bacillus 

 pyocyanus. The experiments of Woodhead and Wood indicate that 

 the antidotal effect is due to chemical products of the growth of the 

 bacillus, and not to an antagonism of the living bacterial cells. They 

 were able to obtain similar results by the injection of sterilized cul- 

 tures of the Bacillus pyocyanus, made soon after infection with the 

 anthrax bacillus. 



96. BACILLUS OP FIOCCA. 



Found by Fiocca in the saliva of cats and dogs. 



Closely resembles the influenza bacillus of Pfeiffer and of Canon. 



Morphology. Resembles the bacillus of rabbit septicaemia, but is only 

 half as large from 0.2 to 0.33 /* in breadth. The length is but little greater 

 than the breadth. Usually seen in pairs, closely resembling diplococci. 

 When cultivated on potato it appears to be a micrococcus, but in the blood 

 of infected animals and in bouillon cultures it is seen to be a short bacillus. 



Stains with difficulty with the usual aniline colors, but is readily stained 

 by Ehrlich's method or with Ziehl's solution. 



Biological Characters. An aerobic and facultative anaerobic, non- 

 liquefying, non-motile bacillus. Spore formation not observed. Grows best 

 at 37 C. and does not develop at temperatures below 15 C. In agar plates, 

 at 37 C., small, punctiform colonies are developed at the end of twenty -four 

 hours; these do not increase in size later; under the microscope the deep 

 colonies are seen to be spherical, granular, and dark yellow in color ; the 

 superficial colonies are more or less round, with irregular outlines, trans- 

 parent, slightly granular, and often have a shining nucleus at the centre. 

 Upon gelatin plates the colonies have a similar appearance, but are not vis- 

 ible in less than four or five days. In streak cultures upon the surface of 

 agar small, punctiform colonies are seen along the track of the needle at the 

 end of twenty-four hours, resembling fine dewdrops; the following day 



