PATHOGENIC BACTERIA. 239 



jjroducing disease, which is fully as important as the typical 

 suppuration seen in an abscess. This happens when the sup- 

 purative condition is complicated by other pathological pro- 

 cesses, or when there is inflammation of another variety with- 

 out suppuration at all; or they may produce lesions which are 

 not inflammatory in a strict sense. These differences in their 

 action depend largely upon the organ affected. One such 

 condition is osteomyelitis, which is suppuration occurring in 

 bone, but. which does not prevent the ordinary picture of pus- 

 formation owing to the hard and unyielding character of the 

 tissue. Other conditions of very great importance are menin- 

 gitis, pericarditis, pleuritis, croupous and broncho-pneumonia, 

 peritonitis and endocarditis. It will be observed that these 

 affections are, for the most part, inflammations of the serous 

 membranes. Such inflammations, when they are produced 

 by pyogenic bacteria, are Hkely to be of great severity, accom- 

 panied by the formation of fibrinous exudates; pus-formation 

 may or may not be present. We find that the cause at times 

 is the Staphylococcus pyogenes aureus; this is often the case 

 in malignant endocarditis. Generally speaking, in such in- 

 flammations the Streptococcus pyogenes, the Staphylococcus 

 pyogenes aureus and the pneumococcus occur most commonly, 

 although they are by no means the only organisms found. 

 Many cases of peritonitis show the presence of B. coli com- 

 munis, either in combination with other bacteria or alone.* 

 This is explained by the proximity of the intestine, and espe- 

 cially by the frequent occurrence of peritonitis after perfora- 

 tion of the intestine. 



In inflammations of mucous membranes the common pyo- 

 genic organisms are usually the cause, though other organisms 

 are occasionally responsible. In acute bronchitis, pneumo- 



* Flexner. Etiology, etc., of Peritonitis. Philadelphia Medical Journal. 

 November 12, 1898. 



