244 PUBLIC HEALTH BACTERIOLOGY 



Koch-Weeks Bacillus. A bacillus similar to the 

 above, but longer and more slender, was described by- 

 Koch in 1883, and by Weeks in 1887, in connection with an 

 epidemic form of acute conjunctivitis. 



Cultures. It grows best on serum agar, and at 37 C ; 

 the colonies appear in 36 hours as dew drops. 



The disease is characterized by a muco-purulent discharge, 

 hyperaemia of the whole of the conjunctiva, and swelling 

 of the lymph follicles of the lids, which show through 

 the palpebral conjunctiva as slightly raised pinkish-grey 

 bodies, a half to one millimetre in diameter. A film made 

 from the discharge and stained with Loeffler's methylene- 

 blue, shows the bacilli. The affection is very contagious, 

 and to prevent epidemics in schools, common face-towels 

 should be rigorously prohibited. 



Bordet-Gengou Bacillus. These observers found 

 a small ovoid bacillus in the sputum of a child suffering 

 from whooping-cough. 



Culture. In 1906, six years later, they succeeded in 

 cultivating it on a special medium, after failing with 

 ascitic agar and blood agar. This medium is a glycerin 

 extract of potato with 4 per cent salt and 2-5 per cent 

 agar, to which is added an equal quantity of defibrinated 

 human or rabbit's blood. On this, inoculated from 

 sputum, the colonies appear within 48 hours, and are small, 

 greyish, and rather thick. In subcultures, they give 

 a more luxuriant growth, and can then be grown on blood 

 agar and in ascitic broth, in which it causes a viscid 

 sediment but no pellicle. It is strictly aerobic, and grows 

 moderately below blood-heat. It remains alive in culture for 

 as long as two months. Specific agglutinins are developed 

 in immunized animals, which serve to distinguish it from 

 B. influenzae. The washed and dried bacilli ground in a 

 mortar and injected into a rabbit intravenously, usually 

 kill it in 24 hours. Specific complement fixation has 

 been used by Bordet and Gengou to prove the identity of 

 the bacillus, using the serum of an infant suffering from 

 whooping-cough. 



The organism is present in the sputum in the early 

 stages in predominating numbers, but later it is 

 swamped by others. It is scattered among the pus cells, 



