. Pathogenic microörganisms; a practical manual for students, physicians, and health officers . ameexudate contain the bacilli abundantly. Because of the uncertainty, therefore,of obtaining a growth by the inoculation of agar with bacilli unaccustomed to. this medium, agar is not a reliable medium for use in primary cultures for diag-nostic purposes. A mixture composed of 2 parts Of a per cent, nutrientagar and 1 part of sterile ascitic fluid makes a medium upon which the bacillusgrows much more luxuriantly, but not so characteristically. Isolation of the Diphtheria Bacillus from Plate Cu
. Pathogenic microörganisms; a practical manual for students, physicians, and health officers . ameexudate contain the bacilli abundantly. Because of the uncertainty, therefore,of obtaining a growth by the inoculation of agar with bacilli unaccustomed to. this medium, agar is not a reliable medium for use in primary cultures for diag-nostic purposes. A mixture composed of 2 parts Of a per cent, nutrientagar and 1 part of sterile ascitic fluid makes a medium upon which the bacillusgrows much more luxuriantly, but not so characteristically. Isolation of the Diphtheria Bacillus from Plate Cultures.—Nutrient or glycerinagar should be melted and poured in the Petri dish for this purpose. After it hashardened, the medium in a number of plates is streaked across with bacteriafrom colonies on the serum culture, which appear in size and color like thediphtheria bacilli. Other plates are made from a general mixture of aU bac-teria, selected, as a rule, from the drier portion of the serum. Still others areinoculated from the pellicles of ascitic broth cultures. The plates are left in. Fig. 121.—Colonies of diphtheria 200 diameters. PATHOGENESIS 297 the incubator for about sixteen hours at 37° C. In the examination of theplates one should first seek for typical colonies, then, if these are not found, forany that look most nearly like the characteristic picture. Diphtheria coloniesare very apt to be found at the edges of the streaks of bacterial growth. Thefishings from the colonies are inoculated upon Lofflers blood serum, or intoascitic bouillon. Growth in Bouillon.—-The diphtheria baciUi from about one-half the culturesgrow readily in broth slightly alkaline to litmus; the other strains grow characteristic growth in neutral bouillon is one showing fine grains. Thesedeposit along the sides and bottom of the tube, leaving the broth nearly few cultures in neutral bouillon and many in alkaline bouillon produce fortwenty-four or forty-eig
Size: 1586px × 1576px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauth, bookcentury1900, bookdecade1910, bookidcu31924000235212
