THE URINE 137 



fine culture. Flake of the pus should be picked out from the 

 fluid, thoroughly washed in normal saline solution, and plate 

 cultures (preferably tube-plates on agar) made. 



THE URINE 



The more important investigations in which the urine has to 

 be examined have been mentioned already. See p. 66 (tubercle 

 bacilh) and p. 89 (gonococci). 



Methods. — Where the examination is to be microscopical and 

 not cultural it is not usually necessary to use a catheter specimen. 

 The urine is to be passed directly into a sterilized vessel (or at 

 least a clean and dry one), the first portion being passed into 

 another vessel and rejected. 



In most cases it is not absolutely necessary to centrifugalize 

 the urine, since the bacteria are commonly present in large 

 numbers, but it is an advantage when this can be done. It is 

 not advisable to allow the urine to deposit spontaneously, as there 

 are many chances of accidental contamination, and many common 

 bacteria grow with great rapidity in urine. 



The examination should commence by the inspection of a 

 hanging-drop preparation, first under the i then under the J^. 

 This will enable you to recognize the presence of motile bacilli, 

 streptococci, other cocci, etc. ; pus, blood, epithelial cells, etc., and 

 crystals. 



Then pass on to film preparations, preferably from the centri- 

 fugalized deposit. Prepare films in the ordinary way and stain by 

 Gram, counterstaining by dilute carbol fuchsin. This will enable 

 you to study the organisms more closely, and to see whether 

 they retain Gram or not. The staphylococcus (which appears 

 in the urine mostly as diplococci) and the M. urea do so, and the 

 gonococcus and the gonococcus-like diplococcus which causes 

 cystitis are decolorized. 



Where cultures are required, a catheter specimen must be used. 

 The catheter must be boiled, and the urinary meatus sterilized. 

 The first portion of the urine is to be rejected, and a small 

 quantity of the last part collected in a sterile test-tube, and the 

 plug immediately replaced. A small quantity only is required. 



Cystitis, Pyelitis, Etc — These may be due to many organ- 

 isms, either pure or mixed, and there is but little practical interest 



