CHAPTER IX. 



BACTERIOLOGICAL DIAGNOSIS. 



EXERCISE CVI. EXAMINATION OF BUCCAL SECRETION. 



DEFINITION. The secretion of the mouth, or saliva, is a mixed product derived iu 

 part from the mucous glands within the mouth and also from the parotid, submax- 

 illary, and sublingual glands In disease the normal character of the different parts may 

 vary or there may be various exudates and growths present. 



COLLECTION. Material for bacteriological examination is best obtained by means of 

 a sterile probang or forceps. This material may be examined directly by means of 

 cover-glass preparations or by means of cultures. 



1. Method of Preparing Outfit. Wind a small piece of absorbent cotton on the end 

 of a wire (about 1 mm. in diameter and 14 cm. long). Thrust the other end of the 

 wire through the cotton plug of a test-tube or fasten in a cork and sterilize at 150 C. for 

 1 hour. This with a tube of nutrient medium (usually Leoffler's Blood serum) is placed 

 in a box for transportation. 



2. Method of Using Outfit. The patient is placed in a good light and the probang 

 gently but firmly rubbed over the suspected area of the throat and then drawn gently 

 over the surface of the medium, both tubes securely stoppered and the outfit sent to the 

 laboratory. The organisms to be sought for are B. diphtheriae, the pyogenic cocci and 

 Monilia Candida. 



BACTERIUM DIPHTHERIAE. 



The presence of this germ in the mouth usually results in a formation of a pseudo- 

 membrane a portion of which is to be removed with a pair of forceps or by means of the 

 outfit described above. It should, 1) be examined directly for the diphtheria bacillus by 

 smearing on a cover-glass and staining by following methods : 



a. Loeffler's methylen blue. 



6. Gram's stain. 



c. Neisser's stain: a. 1 gram methylen blue dissolved in 20 cc. of alcohol (96%), is 

 added to 950 cc. of distilled water and 50 cc. of glacial acetic acid; 6. 2 grams of bismark 

 brown dissolved in a liter of distilled water. Films are stained in a. 2 to 3 seconds, washed 

 in water, stained in 6. 3 to 5 seconds, dried and mounted. 



2) Usually, however, mere microscopical examination is not sufficient, and culture 

 methods must be employed. In fact this method ought always to be used. 



In this case make smears on Loeffler's blood serum and incubate them at 36-38 C. 

 for 12-24 hours and then examine the growth in cover-glass preparations. The diphthe- 

 ria organism if present should show: 



a. Characteristic appearance with Loeffler's methylen blue. 



b. Positive Neisser stain. 



c. Positive Gram stain. 



