6s6 BACTERIA OF THE RESPIRATORY TRACT 



like the varieties that occur commonly in the throat. Many of the non-hemolytic 

 streptococci are distinctly anaerobic when first cultivated. 



On the teeth along the gum margins appear constantly similar radiating growths 

 made up of the same four varieties of organisms. They compose a considerable part 

 of the tartar on the teeth. When removed, the growth returns again in two or three 

 days. 



These organisms may under given manifold conditions cause serious infections. 

 They are prone to develop in tissues which have lost their vitality; for example, when 

 injured by wounds, foreign bodies, vascular changes, tumors, severe infections, an- 

 esthetics, etc. As a result of the growth especially of the spirochetes, fusiform bacilli, 

 and streptococci, there arise infections about the throat, gangrene about the mouth or 

 face (noma), growths on the tonsils (pharyngomycosis), putrid infections of the middle 

 ear, and various lung infections characterized by a foul odor of the breath and sputum, 

 such as pulmonary abscesses, putrid bronchitis, and bronchiectasis and empyema.' 



HEMOPHILIC BACTERIA 



Of all the respiratory bacteria the influenza bacillus of Pfeiffer has attracted most 

 attention recently because of the influenza pandemic of 1918-19. My own work has 

 been along two chief lines :^ first, a study of the nutrition of this organism ; and, second, 

 its distribution and relation to respiratory infections. 



Certain points as regards its nutrition are interesting. If blood or hemoglobin 

 media is heated to boiling or less for a short time (a few minutes), it will support a 

 profuse growth of these bacilli. If boiled for a long time (one to two hours) or if 

 heated to a higher temperature in the autoclave for even a few moments, its value as 

 a culture medium for this organism is lost. But its cultural value is regained, or we 

 may say the media may be reactivated, by adding a small amount of any one of a 

 large group of substances, namely, ascites fluid, serum, animal tissues (free of hemo- 

 globin), plant extracts of various kinds (carrot or potato), dead or live bodies, or ex- 

 tracts of bacteria of various kinds or of yeasts, etc. Heating any one of these sub- 

 stances in the autoclave for a short time will render it inert for purposes of blood-media 

 reactivation. Inorganic substances do not so behave. From these experiments it is clear 

 that we are dealing with the interaction of two substances in this nutritive process. 

 Either one alone will not support growth of this bacillus. The two combined will do 

 so. The one is hemoglobin or one of its heat derivatives which is a relatively stabile 

 body. It is an iron-containing substance and has been shown to be hematin or hemin. 

 The second substance is a labile substance destroyed at autoclave temperature in a 

 few moments or at the boiling temperature in one to two hours. It will pass through 

 filter paper and through porcelain filters without appreciable loss. It resists acids, but 

 appears to be susceptible to alkalies. It is found generally in the juices of both plants 

 and animals. Serum, ascites fluid, extracts of heart, Uver, brain, kidneys, etc., and also 

 extracts of plants, especially carrot and potato, contain it in abundance. Bacteria 



■ Pilot, I., and Davis, D. J.: Arch. Int. Med., 34, 313. 1924. 



* Davis, D. J.: /. Infect. Dis., 21, 392. 1917; ibid., 29, 171. 1921; J.A.M.A., 77, 683. 1921; 

 Proc. Chicago Inst. Med., 2, 142. 1919; J.A.M.A., 64, 1814. 1915; ibid., 48, 1563. 1907. 



