CHAPTER XVIII. 



THE BACILLUS AND THE BACTERIOLOGY OF TETANUS. 



TETANUS is a disease which is characterized by a gradual onset of 

 general spasm of the voluntary muscles, commencing in man most 

 often in those of the jaw and neck, and extending in severe cases to all 

 the muscles of the body. The disease is usually associated with a 

 wound received from four to fourteen days previously. 



In 1884 Nicolaier, under Fliigge's direction, produced tetanus in 

 mice and rabbits by the subcutaneous inoculation of particles of garden 

 earth. The Italians, Carle and Rattone, had just before demonstrated 

 that the pus of an infected wound from a person attacked with tetanus 

 could produce the same disease in rabbits, and showed that the disease 

 was transmissible by inoculation from these animals to others. Finally, 

 Kitasato, in 1889, obtained the bacillus of tetanus in pure culture and 

 described his method of obtaining it and its biological characters. 



Occurrence in Soil, etc. The tetanus bacillus occurs in nature as a 

 common inhabitant of the soil, at least in places where manure has 

 been thrown, being abundant in many localities, not only in the super- 

 ficial layers, but also at the depth of several feet. It has been found in 

 many different substances and places in hay-dust, in horse and cow 

 manure, in the mortar of old masonry, in the dust from horses' hair; 

 in the dust in rooms of houses, barracks, and hospitals; in the air, and 

 in the arrow poison of certain savages in the New Hebrides, who obtained 

 it by smearing the arrow-heads with dirt from crab holes in the swamps. 



Morphology. In young gelatin cultures the bacilli appear as motile, 

 slender rods, with rounded ends, 0.5/* to 0.8/t in diameter by 2 t u to 4// 

 in length, usually occurring singly, but, especially in old cultures, often 

 growing in long threads. They form round spores, thicker than the 

 cell (from I/* to 1.5/J. in diameter), occupying one of its extremities and 

 giving to the rods the appearance of small pins (Fig. 84). 



Staining. It is stained with the ordinary aniline dyes, and is not 

 decolorized by Gram's method. The spores are readily stained and 

 may be demonstrated by double-staining with Ziehl's method. The 

 flagella are fairly easily stained in very young cultures. 



Biology. An anaerobic, liquefying, moderately motile bacillus. It 

 has abundant flagella. Forms spores, and in the spore stage it is not 

 motile. It grows slowly at temperatures from 20 to 24 C., and best 

 at 37 C., when within twenty-four hours it forms spores. It will not 

 in pure culture grow in the presence of oxygen or carbon dioxide gas, 

 but grows well in an atmosphere of hydrogen gas. With certain other 

 bacteria the tetanus bacillus grows luxuriantly in the presence of oxygen. 



