418 



TETANUS 



means of the methods appropriate for anaerobic bacteria. The 

 best methods for dealing with such pus are as follows : 



(1) The principle is to take advantage of the resistance of the 

 spores of the bacillus to heat. A sloped tube of inspissated 

 serum or a deep tube of glucose agar is inoculated with the pus 

 and incubated anaerobically at 37 C. for forty-eight hours, at 

 the end of which time numerous spore-bearing bacilli can often 

 be observed microscopically. The culture is then kept at 80 C. 



FIG. 121. Tetanus bacilli, showing flagella. 

 Stained by Rd. Mnir's method, x 1000. 



for from three-quarters to one hour, with the view of killing all 

 organisms except those which have spored. A loopful is then 

 added to glucose gelatin, and roll-tube cultures are made in the 

 usual way and kept in an atmosphere of hydrogen at 22 C. ; 

 after five days the plates are ready for examination. Kitasato 

 compares the colonies in gelatin plates to those of the b. 

 subtilis. They consist of a thick centre with shoots radiating 

 out on all sides. They liquefy the gelatin more slowly than the 

 b. subtilis. This method of isolation is not always successful, 

 partly because along with the tetanus bacilli, both in its natural 



