320 BACTERIA AND DISEASE 



specific, but secondary or mechanical. Other bacteria in addition 

 to the two named have from time to time been held responsible 

 for pneumonia, a streptococcus receiving, at one time, some support. 

 But whilst opinion is divided as to the rdle of various extraneous 

 and concomitant bacteria in lung disease, importance is attached to 

 Frankel's and Friedlander's organisms. 



The diplococcus of Frankel is a small oval diplococcus found in 

 the "rusty" sputum of croupous pneumonia. It is non-motile, 

 non-liquefying, aerobic, and facultatively anaerobic. When examined 

 from cultures the diplococci are frequently seen in chains, not unlike 

 a streptococcus, and there is some reason to suppose that this form 

 gave rise to the belief that it was another species ; when examined 

 from the tissues, sputum, or pus, it possesses a capsule, like an 

 unstained halo (stained by MacConkey's method), but in culture this 

 is lost except in gelatine at 37 C. (Gordon). Involution forms occur. 

 The diplococcus is difficult to cultivate, but grows on glycerine 

 agar and blood serum at body temperature. . On ordinary gelatine 

 at room temperature it does not grow, or if so, very slightly. The 

 ideal fluid is a slightly alkaline liquid medium, and in twenty-four 

 hours a powdery growth will occur in such broth. On potato there 

 is apparently no growth. The pneumococcus always requires a 

 temperature of about blood-heat for its maximum development. 

 It rapidly loses its virulence on solid media, and is said to be 

 non-virulent after three or four sub-culturings. A temperature of 

 54-58 C. for a few minutes kills the bacteria, but not the toxin. 

 This, however, is removed by filtration, and is therefore probably 

 intracellular. It is attenuated by heating to 70 C. This diplococcus 

 stains by Gram's method (see Plate 22, p. 318). 



Frankel's diplococcus occurs, then, in the acute stage of true 

 croupous pneumonia, in company with streptococci and staphylococci. 

 It is by far the most frequently present organism in croupous 

 pneumonia. It also occurs in the blood in certain suppurative 

 conditions, in pleurisy and inflammation of the pericardium, and some- 

 times in diphtheria, and therefore it is not peculiar to pneumonia. 



Frankel's organism is said to be frequently present in the saliva 

 of healthy persons. Inflammation depresses the resistant vitality 

 of the tissues, and thus affords to the diplococcus present in the 

 saliva an excellent nidus for its growth.* 



Friedlander's Pneumo-bacillus is a capsulated oval coccus, assuming 

 the form of a small bacillus. It is inconstant in pneumonia, unequally 

 distributed, and scarce ; it is aerobic, and facultatively anaerobic ; 



* For further particulars respecting the pneumococcus, see Practitioner, March 

 1900, pp. 280-304 (J. W. Eyre); and Brit. Med. Jour., 1902, vol. ii., pp. 1585, 

 1646, 1704, 1765 (Croonian Lectures on Natural History and Pathology of 

 Pneumonia, by J. W. Washbourn). 



