604 BACTERIA IN INFECTIOUS DISEASES. 



Strelitz (1892) obtained in cultures from pemphigus vesicles a micrococcus 

 which corresponded in every respect with Staphylococcus pyogenes aureus. 

 Inoculation of this micrococcus in his own arm caused the development of 

 typical pemphigus bullae. 



PERICARDITIS. 



Pericarditis is a localized infectious process due to various patho- 

 genic microorganisms. In two cases reported by Barbacci (1892) the 

 micrococcus of pneumonia was found to be the infectious agent. 

 Paviot (1894) reports a fatal case of purulent pericarditis in which a 

 diplococcus was found resembling Friedlander's bacillus. Ernst 

 (1893) obtained from the pericardial sac, in a case in which the tu- 

 bercle bacillus was also present, a variety of Bacillus pyocyaneus. 



In " uraemic pericarditis " Banti failed, in four cases, to find any 

 microorganism in fluid obtained from the pericardial sac. 



In pericarditis occurring in general septica3mic infection the 

 microorganism to which the general infection is due will probably 

 be found in the pericardial sac, and when it occurs as a complication 

 of one of the specific infectious diseases in which bacteria are usually 

 not found in the blood eruptive fevers it is probably due to a mixed 

 infection with one of the common pus cocci. In chronic tubercular 

 pericarditis the tubercle bacillus is the infectious agent. 



PERITONITIS. 



That peritonitis usually results from the presence of microorgan- 

 isms in the cavity of the abdomen seems to be well established by ex- 

 perimental evidence and by bacteriological researches in cases of this 

 disease. Mechanical irritants, like finely powdered glass (writer's 

 experiments) , introduced into the cavity of the abdomen of rabbits, 

 do not cause peritonitis unless microorganisms are introduced at the 

 same time ; the minute fragments of glass become encysted and the 

 animal remains in good health. But Pernice has shown that peri- 

 tonitis may be induced in rabbits and in guinea-pigs by injecting 

 into the cavity of the abdomen various chemical substances, such as 

 concentrated mineral acids, acetic acid, phenol, nitrate of silver, etc. 

 It is also demonstrated by numerous experiments that pure cultures 

 of various bacteria injected into the cavity of the abdomen of the 

 animals mentioned may produce a fibrinous or a purulent peritonitis. 

 Among these is the Bacillus coli communis, which is constantly 

 present in the intestine of healthy persons; and in peritonitis follow- 

 ing perforation of the bowels this bacillus is responsible, in part at 

 least, for the intense peritoneal inflammation which so quickly occurs. 

 In puerperal peritonitis the pus cocci, and especially Streptococcus 

 pyogenes, appear to be the usual cause of the inflammatory process. 



