106 BACTERIOLOGY FOR NURSES 



Examination of Pus. Films should first be made and stained 

 with methylene blue, with carbol fuchsin, and by Gram's method. 

 Whenever the latter method is employed it is advisable to smear 

 on the end of the same slide a small amount of a known Gram 

 positive culture (staphylococcus) and of a known Gram negative 

 one (B. coli) as a control. Occasionally this preliminary exami- 

 nation reveals all it is necessary to know ; if not, a loopful of pus 

 is inoculated into appropriate media and streaks are made on 

 agar and blood or serum agar plates. In most cases it is well to 

 make anaerobic cultures also. When colonies have developed 

 on the plates, media is inoculated and a film made from each 

 variety present ; further methods of identification of species have 

 already been described. 



When the only information required is the knowledge of the 

 presence or absence of a definite species, then only the special 

 methods for the detection of those organisms need be employed. 



Nose and Throat Cultures. The exudate is obtained by means 

 of a sterile swab, which is immediately replaced within its sterile 

 container if the examination cannot be made at once. If the ex- 

 amination is to be made for the diphtheria bacillus the swab is 

 lightly smeared over a sterile slide and then over the surface of 

 Loeffler's serum media. The smear when stained with Loeffler's 

 methylene blue may reveal the presence of B. diphtheria?; if not, 

 the serum culture should be incubated from twelve to eighteen 

 hours. A film prepared from the resulting growth will reveal 

 the organisms if they are present. 



For septic sore throat the procedure is the same save, in addition, 

 plates of blood-smeared agar should be streaked. Long chains of 

 streptococci will, however, generally be seen in the original film. 



For the detection of tubercle bacilli the procedure is the same 

 as for sputum. 



In the case of Vincent's angina the typical fusiform bacilli and 

 spirochetes will be seen in the smear. A strong stain such as 

 gentian violet gives the best picture. 



Sputum. Patients should be instructed to rinse the mouth 

 well, so that particles of food may not be mixed with the sputum. 



