74 STUDY AND IDENTIFICATION OF BACTERIA 



presence of ordinary pus cocci in a tetanus wound may be that the activity of the 

 leucocytes in phagocytizing them allows the tetanus bacillus to escape phagocytosis. 



This would also explain the importance of nec- 

 rotic tissue in a lacerated wound the phagocytes 

 taking this up instead of tetanus bacilli. The 

 toxin is digested by the alimentary canal juices 

 and infection by that atrium is improbable. 

 The infection occurs especially through skin 

 wounds, and also from those of mucous mem- 

 brane. While tetanus is like diphtheria, a dis- 

 ease in which the bacilli are localized and do not 

 spread, yet recently Richardson has obtained 

 tetanus bacilli in pure culture from the tributary 

 lymphatic glands of a "rusty nail" wound of 

 foot. The cultures inoculated into root of tail 

 of a white rat caused the rat's death in forty- 

 eight hours with typical "seal gait" attitude of 

 tetanus in rats. 



The usual period before symptoms occur is 

 fifteen days. The shorter the period of incuba- 

 tion, the more probably fatal the disease. The 

 horse is the most susceptible animal, next the 

 guinea-pig, then the mouse. Fowls are practi- 

 cally immune. 



In examining for tetanus, scrape out 

 the material from the suspected wound 

 with a sterile Volkmann spoon and put 

 it in a tube containing blood-serum. 

 Place this in an incubator. We have 

 here the principle of the septic tank 

 the cocci and other aerobes grow lux- 

 uriantly and enable the tetanus bacillus 

 to develop. From day to day smell the 

 culture, and if an odor similar to the 

 penetrating, sour, foul smell of the stools 

 of a man who has been on a debauch be 

 detected, it is suspicious. The nonde- 

 velopment of a foul odor is against 

 FIG. 24. B. aerogenes capsu- tetanus. Also make smears from the 

 latus agar culture showing gas material and examine for drum-stick 

 formation. (Williams.) T , ,, f 



spores. If these are found, heat the 



material to 80 C. for one-half hour, to kill nonsporing aerobes and 

 facultative anaerobes, and then inoculate a deep glucose agar tube 



