170 PATHOGENIC BACTERIA 



and a fluorescent one. They impart a beautiful green fluores- 

 cence to the tube of culture material. The bacillus has the 

 power to elaborate a gelatin-digesting and a milk-curdling 

 ferment. Its powers of resistance to heat and chemicals are 

 rather high. Materials to be disinfected should be exposed to 

 carbolic acid or formaldehyde solutions for half an hour. 



The poisons of the pyocyaneus bacillus are twofold 

 one an endotoxin, the other a soluble separable toxin. These 

 substances, more especially the latter, have the power of 

 destroying some other bacteria. The broth culture, freed of 

 bacteria and reduced to one-tenth its volume, then called 

 pyocyanase, is used sometimes to rid the throat of persistent 

 diphtheria bacilli. The toxins are more poisonous to animals 

 than are the living cultures. Most small laboratory animals 

 are susceptible to injections of the living pyocyaneus bacillus. 

 The bacilli may multiply within the body and enter the blood 

 stream. It is maintained that some part of the toxin has the 

 power to destroy red blood cells. 



The pyocyaneus bacillus may, by its presence on wounds, 

 delay their healing. It is commonest perhaps in boils in the 

 axilla and groin. It has been found in otitis media and in 

 gastro-enteritis of debilitated children. There may be a 

 general sepsis, under which circumstances pleurisy, peri- 

 carditis, and the like may be looked for. A diagnosis is made 

 solely by finding the pigment- producing bacillus in pus or 

 other exudate, or possibly by blood culture. Active immunity 

 may be produced in the lower animals by exceedingly careful 

 technic, but it has not been found profitable to use the anti- 

 serum upon human beings. Vaccines have been tried in 

 cases of old abscesses, sinuses and the like in which the 

 pyocyaneus bacillus has been a factor, with some betterment, 

 but the reaction following injections is severe and they should 

 be used only by persons thoroughly familiar with their 

 actions. 



