390 APPLICATION OF METHODS OF BACTERIOLOGY 



Inoculation into Animals. As a rule, cultures of this 

 organism obtained directly from the discharges of the wound 

 are capable, when introduced into animals, of producing 

 diseased conditions; but cultures kept on artificial media 

 for a long time may in part, or completely, lose this power. 



When guinea-pigs or rabbits are inoculated subcutaneously 

 with 1 c.c. of virulent fluid cultures of this organism, death 

 usually results in from eighteen to thirty-six hours. At 

 the seat of inoculation there are found an extensive purulent 

 infiltration of the tissues and a marked zone of inflammatory 

 edema. 



When introduced directly into the peritoneal cavity the 

 results are also fatal, and at autopsy a genuine fibrinous 

 peritonitis is found. There is usually an accumulation of 

 serum in both the peritoneal and pleural cavities. At 

 autopsies after both methods of inoculation the organisms 

 will be found in pure cultures in the blood and internal 

 viscera. 



When animals are inoculated with small doses (less than 

 1 c.c. of a bouillon culture) of this organism death may not 

 ensue, and only a local inflammatory reaction (abscess 

 formation) may be set up. In these cases the animals are 

 usually protected from subsequent inoculation with doses 

 that would otherwise prove fatal. 



Most interesting in connection with pseudomonas ceru- 

 ginosa is the statement of Bouchard, and of Charrin and 

 others, that its products possess the power of counteract- 

 ing the pathogenic activities of bacterium anthracis. That 

 is to say, if an animal be inoculated with a virulent anthrax 

 culture, and soon after be inoculated with a culture of pseudo- 

 monas oeruginosa, the fatal effects of the former inoculation 



