BORDET-GENGOU BACILLUS 507 



resembling the growth of typhoid bacilli. In these later generations, 

 also, they develop readily upon plain blood agar or ascitic agar and 

 in ascitic broth or broth to which blood has been added. In the 

 fluid media they form a viscid sediment, but no pellicle. 



Culturally, the bacillus varies from B. influenzae in growing less 

 readily on hemoglobin media than the latter, on first cultivation 

 from the sputum. Later it grows much more heavily on such media 

 and shows less dependence upon the presence of hemoglobin than 

 does B. influenzae. It also grows rather more slowly than the influ- 

 enza bacillus. It is strictly aerobic and in fluid cultures is best 

 grown in wide flasks with shallow layers of the medium. 



The Bordet-Gengou bacillus grows moderately at temperatures 

 about 37.5 C., but does not cease to grow at temperatures as low 

 as 5 to 10 C. On blood agar and in ascitic broth it may remain 

 alive for as long as two months (Wollstein). 



Pathogenicity. As regards the pathogenicity and etiological 

 specificity of this organism for whooping-cough, no positive state- 

 ment can as yet be made. The fact that it has been found in many 

 cases in almost pure cultures during the early paroxysms, renders it 

 likely that the organism is the specific cause of the disease. Mallory 

 and Homer 4 have found bacilli appearing to be Bordet and Gengou 's 

 organisms lying between the cilia in the tracheal epithelium of 

 whooping cough cases that have come to autopsy. However, in 

 early cases true influenza bacilli have been often found, and these 

 latter seem to remain in the sputum of such patients for a longer 

 period and in larger numbers than the bacillus of Bordet and 

 Gengou. Endotoxins have been obtained from the cultures of the 

 bacilli by Bordet and Gengou by the method of Besredka. 5 The 

 growth from slant cultures is washed up in a little salt solution, dried 

 in vacuo, and ground in a mortar with a small, measured quantity of 

 salt. Finally, enough distilled water is added to bring the salt into a 

 solution of 0.75 per cent and the mixture is centrifugalized and de- 

 canted. One to two c.c. of such an extract will usually kill a rabbit 

 within twenty-four hours after intravenous inoculation. Subcu- 

 taneous inoculation produces non-suppurating necrosis and ulcera- 

 tion without marked constitutional symptoms. 



Inoculation of monkeys with the bacilli themselves by the respira- 

 tory path has failed to produce the disease. 



4 Mallory and Homer, Journ. Med. Ees. xxvii, 1912, p. 115. 

 fi Bordet, Bull, de la Soc. Eoy. de Brux., 1907. 



