TYPHOID-COLON GROUP 99 



Strong and Teague have shown that of 39 plates exposed before the mouths of 

 patients with pneumonic plague, with marked dyspnoea and pulmonary oedema, but 

 without coughing, only one plate showed plague bacilli. In 39 other experimental 

 plate cultures with coughing on the part of the patients there were 15 plates showing 

 plague bacilli. 



The droplet method of infection is therefore the important one in plague 

 pneumonia. 



As these droplets are expelled to a considerable distance not only should the 

 respiratory inlets be protected by masks but the conjunctivas with glasses and 

 abrasions with protective coatings. 



For diagnosis make smears and cultures from material drawn from 

 a bubo by a syringe. (At a later stage, when softening begins, there may 

 not be any bacilli present.) Also, if pneumonic plague, from the 

 sputum. Blood cultures and even blood smears may be employed in 

 septicaemic plague. Formol fuchsin and Archibald's stain make satis- 

 factory stains. Always inoculate a guinea-pig with the material either 

 by rubbing it in with a glass spatula on the shaven skin or by sub- 

 cutaneous injection. For prophylaxis the most important method is 

 that of Haffkine. Stalactite bouillon cultures of plague are grown for 

 five to six weeks. These are killed by a temperature of 65 C. for one 

 hour. Lysol (1/4%) is added to the preparation and from 0.5 to 4 c.c. 

 injected, according to the age and size of the individual treated. Sus- 

 ceptibility is reduced about one-fourth, and of those attacked after 

 previous vaccination, the mortality is only about one-fourth of what it is 

 among the noninoculated. Strong prepares a prophylactic vaccine 

 from living plague cultures rendered avirulent. Yersin's serum, made 

 by injecting horses with dead plague cultures and afterward with 

 living ones, is of value prophylactically and has possibly considerable 

 curative power. 



The Eberth, Gartner and Escherich Groups. From a standpoint 

 of cultures in litmus milk and sugar bouillon we can divide the organ- 

 isms related to typhoid at one extreme and the colon at the other into 

 three groups. 



i. The Eberth or typhoid group. There are three important patho- 

 gens in this group: the B. typhosus, the B. dysenteriae, and the 3. 

 faecalis alkaligenes. The color of litmus milk is practically uhaltereU' 

 and there is no gas production in either glucoSecr lactose bouillon. Np 

 coagulation of milk. No reduction' oi ftcutral red. ' The J3. typb'osiis. 

 and the B. faecalis alkaligenes are actively motile, while' the B. dysen- 

 teriae is nonmotile or practically so. 



