112 LABORATORY BACTERIOLOGY 



EXERCISE L 



BACTERIOLOGIC EXAMINATION OF PUS AND 

 EXUDATES 



164. It is often very desirable for diagnostic purposes to 

 make a bacteriologic examination of the pus from abscesses 

 and the mucopurulent discharges or exudates from mucous 

 or serous membranes. 



Several diseases can be diagnosed in this way. It is often 

 necessary to make cultures and it is always advisable to do so 

 whenever the material is in a suitable condition. Among the 

 specific diseases for which such an examination is especially 

 valuable are actinomycosis, gonorrhea, diphtheria, and tuber- 

 culosis. Further, it is often desirable to determine the genera 

 of the bacteria in the numerous abscesses and suppurating 

 wounds encountered in both man and the lower animals. 

 Such examinations of the more desirable cases will be made 

 from time to time as they become available. In this exercise 

 such cover-glass preparations will be examined as have been 

 accumulated for this purpose. 



165. Work for this exercise. Examine the pus in the fresh 

 condition and note its composition, leucocytes, red blood 

 corpuscles, fungi (actinomycosis), etc. 



Make cover-glass preparations and stain one or more of 

 them with carbol fuchsin and one with alkaline methylene 

 blue and examine. Note the cellular tissue elements present 

 and describe the bacteria found. If the pus is from a case 

 suspected to be of a specific nature, stain and examine for the 

 corresponding organism. 



If actinomycosis, the ray fungus may be seen better in the 

 fresh preparation. Add a drop of a io% solution of caustic 

 potash to a loopful of pus on the slide and cover it with a 

 cover glass and examine. 



