134 



DIPHTHERIA AND PSEUDODIPHTHERIA. 



The Bacillus diphtheria? is found a. in false membranes of 

 diphtheritic origin ; b. occasionally in the mouth and nose of 

 healthy individuals ; and c. in the dust of rooms inhabited 

 by diphtheritic patients, or on articles of clothing or furniture 

 which, though they may not have come into direct contact 

 with the patients, yet have been in the. same room with them. 



Morphology. The Klebs-Loeffler bacillus is a short rod, 

 from 2 to 6 mikrons in length, and from 0.2 to 0.8 mikron 

 in breadth, being found longer in certain cultures than in 

 others, and when grown for several generations in artificial 

 media. The rods occur singly or in pairs, or in irregu- 

 lar groups ; they may be straight or sometimes slightly 

 curved. Occasionally one or both of the extremities are 

 thicker than the rest of the body of the cell ; at other times 

 the centre of the cell bulges and the end of the cell tapers 

 (Figs. 56, 57, 58). 



FIG. 56. 



FIG. 57. 



One of very characteristic forms of 

 diphtheria bacilli from blood-serum 

 cultures, showing clubbed ends and ir- 

 regular stain. X 1100. Stain, meth- 

 ylene-blue. (Park.) 



Extremely long form of diphtheria 

 bacillus. This culture has grown on 

 artificial media for four years and pro- 

 duces strong toxin. X 1100. (Park.) 



Bacillus diphtherice stains with all of the anilin dyes and 

 by Gram's method, but better with Loeffler's alkaline meth- 

 ylene-blue solution. For the purpose of differentiation the 

 Neisser special stain is often used. 



The bacilli cells do not stain uniformly ; they contain large 



