MYCOBACTERIACEiE: THE BACILLUS OF DIPHTHERIA 3 II 



and Gram-negative. It occurs in large numbers between the 

 cilia of the epithelial cells lining the trachea and bronchi in cases 

 of whooping cough where it rnechanically^ interferes with the 

 action of the cilia and gives rise to irritation. It is an obligate 

 aerobe and at first grows well only on media containing blood, 

 ascitic fluid or other protein. Later it adapts itself to artificial 

 culture on ordinary media. Gelatin is not liquefied. 



Bacillus (Hemophilus) Influenzae.^ — Pfeiffer in 1892 isolated a 

 small bacillus 0.25/1 wide by 0.5 to 2.0/1 long from the bronchial 

 secretion in cases of epidemic influenza. The bacillus occurs in 

 enormous numbers in acute uncomplicated cases of influenza 

 in the nasal and bronchial mucus. It is non-motile, aerobic, 

 rather diflicult to stain and Gram-negative. Cultures are ob- 

 tained on ordinary agar smeared with fresh human or rabbit's 

 blood or upon a mixture of blood and agar. Hemoglobin seems 

 essential to growth. The bacillus is very sensitive to drying, 

 and its transmission would seem to occur largely through close 

 association, and the scattering of moist droplets of material, 

 from the nose and mouth in sneezing, coughing and talking. 

 The cultures are toxic for rabbits and monkeys. The causal 

 relation of B. influenzce to influenza is not as yet fully established. 

 Conditions resembling influenza very, closely seem to be caused 

 by other organisms, such as the cocci. 



The influenza pandemic of 1918 has stimulated numerous 

 investigations of the disease but the bacteriology of it has not 

 been fully elucidated.^ 



' Mallory: Pertussis: The Histological Lesion in the Respiratory Tract, Journ. 

 Med. Rsch., 1912, Vol. XXVII, pp. 115-124; Mallory, Hornor and Henderson, 

 Journ. Med. Rsch., 1913, Vol. XXVII, pp. 39i~397- 



^ Park : Bacteriology of recent pa ndemic of influenza and complicating infections, 

 Journ. Amer. Med. Assn., 1919, 73,P- 318; Huntoon and Hannum: 'S.tXe oi Bacillus 

 influenza in clinical influenza, Journ. of Immunology, 1919, 4, p. 167; MacNeal: 

 The influenza epidemic of 1918 in the American Expeditionary Forces in France 

 and England, Archives Int. Med., 1919, 23, p. 657; Blake and Cecil: The production 

 of an acute respiratory disease in monkeys by inoculation with Bacillus influenza, 

 Journ. A. M. A., Jan. 17, 1920, 74, p. 170. 



