CHAPTER XII. 



THE PROCURING OF MATERIAL FOR BACTERIOLOGICAL EXAMI- 

 NATION FROM THOSE SUFFERING FROM DISEASE. 



A LONG experience has taught me that physicians very frequently 

 take a great amount of trouble, and yet, on account of not carrying out 

 certain simple but necessary precautions, make worthless cultures or 

 send material almost useless for bacteriological study. 



In making cultures from diseased tissues various procedures may 

 be carried out, according to the facilities which the physician has and 

 the kind of information that he desires to obtain. From the dead body 

 culture material should be removed at the first moment possible after 

 death. Every hour's delay makes the results less reliable. From both 

 dead and living tissues the less the alteration that occurs in any sub- 

 stance between its removal from the body and its inoculation upon or 

 in culture media or animals the more exact the information which will 

 be obtained from its examination. If the material is allowed to dry 

 many bacteria will be destroyed in the process, and certain forms which 

 were present will be obliterated or, at least, entirely altered in the pro- 

 portion which they bear to others. If possible, therefore, culture media 

 should be inoculated in the neighborhood of the patient or dead body. 

 For that purpose a bacteriologist should take the most suitable of the 

 culture media to the bedside or autopsy table. Such a list of media, 

 if fairly complete, would comprise nutrient bouillon alone and mixed 

 with one-third its quantity of ascitic fluid, slanted nutrient agar, slanted 

 agar streaked with rabbit or human blood, and firmly solidified slanted 

 blood serum. If only one variety of media is to be used the solidified 

 blood serum is most useful for parasitic bacteria, and this can be easily 

 carried by the physician and inoculated by him, even if he is not 

 very familiar with bacteriological technique. The material must be 

 obtained in different ways, according to the nature of the infection. 



For the detection of the bacteria causing septicaemia we are met 

 with the difficulty that there are apt to be very few organisms present 

 in the blood until shortly before death. It will, therefore, be use- 

 less to take only a drop of blood for cultures, as even when present 

 there may not be more than eight or ten organisms in a cubic centi- 

 metre. If cultures are to be made at all, it is, therefore, best to make 

 them correctly by taking from 5 to 20 c.c. of blood by means of a 

 sterile hypodermic needle, or a suitable glass tube armed with a hypo- 

 dermic needle, from the vein of the arm, after proper cleansing of the 

 skin and a tiny incision. Into each of five different tubes containing 

 bouillon we add 1 c.c. of blood, and into a flask containing 100 c.c. we 



