508 PFEIFFER'S BACILLUS 



obtained by Kitasato and by Bruschettini and Canon were not cultures of Pfeiffer's 

 bacillus. 



Ascitic fluid media are not, as a rule, of much use for growing Pfeiffer's bacillus 

 though very suitable for Elmassian's micro-organism. 



SECTION III. BIOLOGICAL PROPERTIES. 

 1. Vitality and Virulence. 



Pfeiffer's bacillus is very sensitive to heat and drying. In sputum which 

 is kept moist the organism retains its vitality for 14 days ; but if allowed to 

 dry at ordinary temperatures, the organism is killed in 36 hours. Desicca- 

 tion at 37 C. sterilizes cultures of the bacillus in 2 hours and at ordinary 

 temperatures in 24 hours. 



In cultures on blood-agar, the bacillus lives for a week to a fortnight ; and 

 by sub-cultivating on this medium every 4 or 5 days it can be kept alive for 

 several months. In a collodion sac in the peritoneal cavity of a rabbit the 

 organism lived for nearly 2 months (Dujardin-Beaumetz). 



The virulence of Pfeiffer's bacillus is subject to considerable variation. 

 By mixing the organism with streptococci and passing the mixture through 

 mice the virulence can be raised for a short period but not for long. 



2. Toxin. 



Cultures killed with chloroform or heat are toxic. Heated cultures inocu- 

 lated into the cerebro-spinal fluid of rabbits killed the animals in 2-3 hours 

 (Martin and Dujardin-Beaumetz). 



Slatineano prepared an endo-toxin as follows : 



Cultures on blood-agar 24 hours old, either living or killed by heat at 55 C. 

 were -made into an emulsion with normal saline solution, centrifuged and the deposit 

 dried. 0*25 gram of dried bacilli were mixed with 10 c.c. of a mixture of equal 

 parts of distilled water and normal horse serum, left in the ice chest for 12 hours 

 and then centrifuged. 



The supernatant liquid, in doses of O045 c.c., inoculated into the brain of 

 guinea-pigs, proved fatal in 6-10 hours, and when given in quantities of 5 c.c. 

 into the peritoneal cavity the animal died in a few days. 



3. Immunity. Serum therapy. 



Kolle and Delius failed to immunize animals against Pfeiffer's bacillus 

 but Slatineano, Cantani, and Latapie, obtained more promising results. 



Cantani inoculated guinea-pigs sub-cutaneously with increasing doses of very 

 virulent cultures on blood-agar sterilized at 56 C. One guinea-pig was inoculated 

 with 181 cultures over a period of 4 months. The animals were then tested by 

 inoculating many times the minimal lethal dose into the peritoneal cavity. Many 

 of the animals did not survive the immunizing process, but those which did proved 

 to be highly immune and were able to resist the intra- peritoneal inoculation of 100 

 lethal doses. The serums of the immunized animals exhibited prophylactic pro- 

 perties in different degrees : the best results were obtained when the test animal was 

 inoculated with the serum of an immunized animal mixed with a virulent culture. 



Latapie immunized a goat by inoculating it first with dead then with 

 living cultures of a strain of Pfeiffer's bacillus isolated from a case of influenza ; 

 several inoculations were given and the immunizing process was extended over 

 a year. The animal was bled 1 month after the last inoculation, and tho 

 serum was found to be capable of protecting guinea-pigs against two or three 

 fatal doses of the bacillus, provided that it was inoculated in doses of 1-3 c.c. 

 either sub-cutaneously several hours before, or intra-venously a few hours 

 before, the test inoculation. 



