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CULTUEING URINE 



icn the 



Authorities generally insist upon a catheterized specimen in all cases when 

 urine is to be cultured. As a matter of fact when there is a bacterial infection the 

 specific organism is in such predominant numbers that it is easily distinguished 

 from a possible contaminator. Of course should one culture the urine in a tube of 

 bouillon, before plating out, a contamination might overgrow the causative organism, 

 but one should always plate directly from urine which has just been passed. The 

 smear stained by Gram's also checks up, particularly if certain bacteria are found 

 phagocytized in pus cells. The man who follows the clinical side as well as the labora- 

 tory one is rarely confused by an occasional contaminating organism on a plate 

 made from urine or blood. Of course the problem is more difficult with urine, 

 but when culturing of urine is a routine procedure the worker soon knows the organ- 

 isms likely to be encountered in urine of women as well as that of men. As a matter 



Oxyhemoglobin 



Methemoglobin 



Reduced 

 Hemoglobin 



CO Hemoglobin 



FIG. 105. Principal Blood Spectra. (Da Costa.} 



of fact I rarely find colonies on plates made from the urine of normal men, the only 

 precautions taken being those noted below. I now use blood agar plates as routine 

 plating media. 



The glans penis and meatus should be thoroughly washed with soap and water, 

 after which dilute alcohol (70%) should be used. The greater part of the urine 

 first passed should be rejected and only the last portion passed should be caught 

 in a sterile receptacle. A drop of this urine may be either streaked over the 

 surface of an agar, blood agar, or a lactose litmus agar plate, or so treated after 

 being first diluted in a tube of sterile bouillon. 



The lactose litmus agar medium is very useful in distinguishing 

 typhoid or paratyphoid colonies (blue) from colon, and Streptococcus 



