676 INDEX OF INFECTIOUS DISEASES. 



rather to some inflammation resulting from any cause aggravated 

 by the presence of pyogenic micrococci. 



Coryza. It is doubtful whether this affection is due to the action 

 of any one specific micro-organism. Bacteria, however, play a part 

 in keeping up the inflammation in acute and chronic nasal catarrh ; 

 and in ozaena the offensive odor of the nasal secretions seems to be 

 due to the presence of certain bacteria, as Hajek's B. foetidus ozsense. 



Cystitis. It has been shown by recent investigations that cyst- 

 itis is not caused by the mere presence of most varieties of bacteria 

 in the bladder, except, perhaps, by a few varieties, such as the gono- 

 coccus, 528, provided it be healthy ; but when the mucous membrane 

 is injured by mechanical violence, or by the presence of a foreign 

 body, cystitis is likely to result from the introduction of bacteria. 

 The micro-organisms most frequently concerned in the development 

 of chronic cystitis are the colon, 449, bacillus, the typhoid bacillus, 

 the bacillus aerogenes, and varieties of the proteus bacillus. Among 

 other bacteria which have been found in the bladder, and which may 

 influence the production of chronic inflammation, are the tubercle 

 bacillus, staphylococcus pyogenes aureus and allied species, the uro- 

 bacillus, and the urobacillus liquefaciens septicus of Krogius. 



Dengue. No specific micro-organism has been found in this dis- 

 ease which would seem to bear a causal relation to it. 



Dental Caries. According to Miller (1894), who has made an 

 exhaustive study of the bacteriology of dental caries, it is a mixed 

 infection due to the presence of various micro-organisms in the pulp, 

 cocci and bacilli being about equally frequent, with the occasional 

 appearance of spiral forms. The typical pyogenic cocci are seldom 

 present in the pus from the pulp, but various allied species are 

 found which cause pus formation in mice. Putrefactive processes, 

 also the result of bacterial action, greatly increase the action of the 

 pulp cocci. 



Diarrhoea. The action of bacteria in the production of diarrhoea 

 has already been referred to under cholera infantum and cholera 

 nostras There is no reason to suppose that any particular micro- 

 organism is the specific cause of this class of diseases, which are due 

 probably to the toxins produced by various bacteria. Those which 

 would seem to have most to do with the production of these troubles 

 are bacilli of the colon and proteus groups. 



Diphtheria. The Klebs-Loffler bacillus, 349, is now recognized 

 to be the specific cause of diphtheria. Other bacteria, however, are 

 always associated with this, producing more or less of mixed infec- 



