CHAPTER XXXVIII 



BORDET-GENGOU BACILLUS, MORAX-AXENFELD BACILLUS, ZUR 

 NEDDEN'S BACILLUS, DUCREY BACILLUS 



BORDET-GENGOU BACILLUS 



{" Microbe de la Coqueluche," Pertussis hacillns, Bacillus of whooping- 

 cough.) 



In 1900 Bordet and Gengou ' observed in the sputum of a child 

 suffering from pertussis a small ovoid bacillus which, though similar to 

 the influenza bacillus, showed a number of morphological characteristics 

 which led them to regard it as a distinct species. As they were at first 

 unable to cultivate this organism, their discovery remained ques- 

 tionable until 1906, when cultivation succeeded and the biology of the 

 microorganism was more fully elucidated. 



Morphology. — The morphology of this organism is described by 

 them as follows : The organism in the sputum, early in the disease, is 

 scattered in enormous numbers indiscriminately among the pus cells, 

 and at times within the cells. It is extremely small and ovoid, and 

 frequently is so short that it resembles a micrococcus. Often its poles 

 stain more deeply than the center. In general, the form of the or- 

 ganisms is constant, though occasionally slightly larger individuals 

 are encountered. They are usually grouped separately, though occa- 

 sionally in pairs, end to end. 



Compared with the influenza bacillus in morphology, the bacillus 

 of pertussis is more regularly ovoid and somewhat larger. It has, 

 furthermore, less tendency to pleomorphism and involution. 



Staining. — The Bordet-Gengou bacillus may be stained with alkaline 

 methylene-blue, dilute carbol-fuchsin, or aqueous fuchsin solutions. 

 Bordet and Gengou recommended as a staining-solution carbolated 

 toluidin-blue made up as follows: 



Toluidin-blue 5 gras. 



Alcohol 100 c.c. 



Water 500 c.c. 



1 Bordet et Gengou, Ann. de I'inst. Pasteur, 1906. 

 543 



