108 BACTERIOLOGY FOR NURSES 



off, more urine added to the sediment, and recentrifuged. All the 

 fluid is then removed and films and streak plates made from the 

 sediment. If necessary an animal is inoculated. 



Feces. A great variety of bacteria are present in feces. Very 

 few, however, are considered of pathological significance. The 

 different forms may be isolated by inoculating a tube of broth with 

 a small amount of feces and streaking pour plates with the result- 

 ing emulsion. 



Bacterial examination of feces is generally made for the isolation 

 of the typhoid bacillus, less often for the cholera spirillum. The 

 methods employed will be considered in the special sections. 



Examinations are occasionally made for the detection of tubercle 

 bacilli in feces. It is considered of doubtful significance, however, 

 since they may be present in the feces of persons suffering from 

 pulmonary tuberculosis as a result of swallowing sputum. 



Ear Cultures. From the discharge a culture is made on Loef- 

 fler's serum and also two film preparations; one of the latter is 

 stained by Gram's method, the other by a method appropriate for 

 the detection of any special species thought to be present. The 

 culture is examined after eighteen to twenty-four hours' incuba- 

 tion and if necessary the resulting growth is plated on agar to 

 isolate the organisms in pure culture and prove their identity. 



Eye Cultures. The procedure is the same as above except 

 that in addition to culturing on Loeffler's serum cultures should 

 also be made on blood agar. 



Blood Cultures. In order to detect organisms occurring in 

 the blood in relatively small numbers, such as the typhoid bacillus, 

 it is often necessary to make blood cultures. The skin should be 

 thoroughly cleansed as for a surgical operation and 10 to 15 c.c. 

 of blood withdrawn from the median basilic vein of the arm by 

 means of a sterile hypodermic needle and syringe. Whenever 

 possible it is best to inoculate the culture media at the bedside 

 while the blood is liquid. If this is not convenient coagulation may 

 be prevented by drawing into the syringe before the needle is in- 

 serted into the vein an equal quantity of 2 per cent sodium citrate 

 or by immediately transferring the blood to a test tube containing 



