174 Medical Bacteriology. 



SPECIAL BACTERIOLOGICAL METHODS. 



Particular organisms may be stained as follows : 

 Pyogenic micrococci. Loeffler's or Weigert's method. 

 Micrococcus gonorrhoea*,. Loeffler's method gives the best results. 

 Sarcina tetragena, Loeffler's or Weigert's method. 

 Bacterium unthracis. Loeffler's or Weigert's method. 

 Bacterium pneumoniae. Weigert's method. 



Bacterium pneumonic-urn. The following method is recommended for staining the cap- 

 sules in sections (M. & W.) : 



a. Stain for 24 hours in the incubator in the following solution: 



Saturated alcoholic solution of gentian violet - 50cc. 



Distilled water - lOOcc. 



Glacial acetic acid lOcc. 



b. Wash out in 1% solution of acetic acid. 



c. Alcohol. 



d. Xylene. 



e. Canada balsam. 



Bacterium cuniculicida. Loeffler's Method. 

 Bacterium tuberculosis. 



a. Weigert's method (staining with auilin oil gentian violet 24 hours at room 

 temperature, or 2-3 hours at 40 C.). 



b. Ziehl-Neelsen's Method. 



1. Stain with carbol-fuchsin (12-24 hrs. room temperature, 1-3 hrs. 40 C.) 



2. Decolorize with nitric acid (10%) a few seconds and then with alcohol (60-90%) 

 until color is nearly all extracted. 



3- Counter-stain with methylen blue. 



4. Dehydrate with absolute alcohol (a few seconds). 



5. Clear with clove oil. 



6. Xylene (and examine). 



7. Mount in balsam. 



Bacterium leprae. This organism is stained with the tubercle stain, unless the sec- 

 tions have been kept in alcohol for some time, in which case Weigert's method can be 

 employed. To differentiate this organism from B. tuberculosis, stain as follows: 



a. An aqueous solution of fuchsin 6-7 minutes. 



b. Acid alcohol (nitric acid 1, alcohol 10) \ minute. 



c. Wash in water. 



d. Counter-stain in a saturated aqueous solution of methylen blue. 



e. Alcohol. 

 /. Xylene. 

 g. Balsam. 



The bacteria of leprosy stain readily by this method, tubercle bacteria do not. 

 Bacterium mallei. 

 Slow Method. 



a. Stain in Loeffler's methylen blue 6-8 hours. 



b. Wash in distilled water. 



c. Tannic acid solution (10 %) 4-5 hours. 



