402 PATHOGENIC BACTERIA. 



10 cases, streptococci associated with diphtheria bacilli 

 five times and with Staphylococcus pyogenes aureus three 

 times. The diphtheria bacillus occurred alone in 7 cases. 

 The Staphylococcus pyogenes aureus and the pneumo- 

 coccus each alone once and both together once. 



"The clinical significance of this general infection 

 with the Klebs-LofHer bacillus is not apparent. It 

 occurred generally, but not always, in the gravest cases, 

 or those known as ' septic ' cases. It is probable that 

 it may be due to a diminished resistance to the tissue- 

 cells, or of the germicidal power of the blood. In this 

 series of fatal cases the number of infections with the 

 streptococcus and with the Klebs-L,6ffler bacillus was 

 about even, though slightly in favor of the strepto- 

 coccus." 



The mixed infections are simply diphtheria plus the 

 pathogenic effects of the combined bacteria. The diph- 

 theria bacillus probably begins the process, growing 

 upon the mucous membrane, devitalizing it, and produc- 

 ing the coagulation-necrosis. Whatever pyogenic germs 

 happen through accident to be present are thus afforded 

 an opportunity to enter ; and added to the diphtheria 

 there may be ulceration, suppuration, gangrene, etc. , at 

 the seat of local disease, and metastatic abscesses from 

 lymphogenic and hematogenic distribution of the 

 pyogenic bacteria. 



It may be well to remark that all pseudomembranous 

 diseases of the throat are not diphtheria, but that some 

 of them, exactly similar in clinical picture, result from 

 the activity of the pyogenic organisms alone, and are 

 neither diphtheria nor contagious. 



Diphtheritic inflammations of the throat are not always 

 accompanied by the formation of the usual pseudomem- 

 brane. It occasionally happens that in the larynx a rapid 

 inflammatory edema without a fibrinous surface-coating 

 causes a fatal suffocation. Only a bacteriological exam- 

 ination will reveal the nature of the disease in such cases. 



The pseudomembrane which characterizes diphtheria 



