. Preventive medicine and hygiene. Fig. I the flexible wire holding the swab is containedwithin the bent glass tube; in Fig. II it is extruded as in use. The swab is here re-duced one-half in size. The Recognition of Meningococcus Carriers.—The specimenshould be taken from the roof of the nasopharynx, with a sterile cottonswab, guarded by a glass tube, as shown in the illustration (Fig. 193). DISEASES OF THE SOLDIER 1263 It is important to prevent contaminations by organisms in the mouthand saliva. The meningococcus is very frail, and therefore the plates should bemade immediately. It is very
. Preventive medicine and hygiene. Fig. I the flexible wire holding the swab is containedwithin the bent glass tube; in Fig. II it is extruded as in use. The swab is here re-duced one-half in size. The Recognition of Meningococcus Carriers.—The specimenshould be taken from the roof of the nasopharynx, with a sterile cottonswab, guarded by a glass tube, as shown in the illustration (Fig. 193). DISEASES OF THE SOLDIER 1263 It is important to prevent contaminations by organisms in the mouthand saliva. The meningococcus is very frail, and therefore the plates should bemade immediately. It is very sensitive to acid and is soon destroyedby the acidity of contaminating organisms. Sodium chlorid is also toxicto tbe meningococcus, and therefore salt solution should not be used asa diluent, and salt is commonly omitted from the culture media. The meningococcus may be grown iipon sheep-serum dextrose agar;ascitic agar, blood-serum agar, pea-extract trypsin agar which has re-cently been recommended by Gordon,^ or liver agar. V/. Fig. 193.—Diagram Illtjstrating the Method of Taking Material from the Naso-pharynx BY Means of a Special Swab. W—wire holder of S—swab; P—softpalate; D—tongue depressor. (After Dopter.) The sheep-serum agar is made with one part of sheep serum andthree parts of double distilled water. The sheep serum is obtained byclotting and centrifuging. This diluted serum is then sterilized frac-tionally in the Arnold for thirty minutes on three successive days. Theagar is prepared separately with 2 per cent agar and 1 per cent peptonereaction to phenolphthalein. The plates are made by adding 1 the diluted sheep serum to 5 of the liquefied agar at 40° C. Three or four petri plates are seeded with the swab. These platesare then incubated over night, or about fourteen hours at 37° C. Watchfor small moist colonies with regular outline; then let the plates standat room temperature (about 25° C.) for several hours. This permitsthe colonies
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Keywords: ., bookauthorwh, bookcentury1900, bookdecade1910, booksubjecthygiene
