1 64: BACTERIOLOGY. 



CHAPTER XXVIII. 

 PATHOGENIC BACTERIA. 



In all practical work with pathogenic bacteria, more than ordi- 

 nary care should be used. While the danger attending such work 

 should not be unduly magnified, the student will do well to attend 

 carefully to any abrasions on the skin; he should be scrupulously 

 neat and cleanly, not allowing the material used to be carelessly scat- 

 tered; he should dispose of all material as soon as used, and care- 

 fully cleanse the hands at the close of each period. It is doubt- 

 less true that Bacillus mallei has caused the death of more bac- 

 teriologists from accidental infection than all other species to- 

 gether. The diseases known to be produced in man by bacteria are 

 tuberculosis, leprosy, glanders, anthrax, tetanus, erysipelas, gonor- 

 rhoea, pneumonia, influenza, diphtheria, typhoid fever, Asiatic chol- 

 era, relapsing fever, malignant edema, bubonic plague, and sup- 

 puration. It is believed that some kind of micro-parasite will be 

 found to be the specific cause of each of the following diseases viz., 

 syphilis, mumps, smallpox, chicken pox, measles, scarlet fever, yel- 

 low fever, whooping cough, and others. The limited space of this 

 Manual will allow but a brief discussion of a few of the more im- 

 portant species. 



I. Bacillus Tuberculosis. 



This species is the recognized cause of consumption, or tubercu- 

 losis. It is a non-motile facultative saprophyte, and consists of 

 slender, beaded staves. It may be cultivated on glycerine agar-agar, 

 growing best at 37 degrees Centigrade. It -reproduces by fission, 

 and probably by spore-formation. It is also pathogenic to a num- 

 ber of animals. Man may become infected through wounds, through 

 nutrition such as the milk of tuberculous cows and by inhala- 

 tion. The sputum of the consumptive, if not properly destroyed, 

 dries and becomes pulverized. As dust, it floats in the atmosphere, 

 is inhaled, and under suitable conditions produces infection. It is 

 doubtful whether any one is immune from the disease. 



