Mycology of the mouth : a text-book of oral bacteria.

  • Goadby, Kenneth (Kenneth Weldon), Sir, 1873-
Date:
1903
Catalogue details

Licence: Public Domain Mark

Credit: Mycology of the mouth : a text-book of oral bacteria. Source: Wellcome Collection.

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    the saliva experimentally proved by Sanarelli. Sanarelli! filtered saliva through a Pasteur-Chamberland filter and tested the filtrate in the following way :— A small quantity of a pure cultivation of staphylococcus aureus, just as much as could be taken up on the point of a platinum needle, was added to 10 cubic centimetres of saliva sterilised by filtration. After mixing, plate cuitivations were made, and the number of organisms present determined. Plate cultures were then made at intervals, and by this means it was found that the number of colonies developing gradually diminished, and in thirty-six hours no staphylococci were present. If, however, a whole loopful of the cultivation was added, the plate cultivations still showed a diminution in the number of organ- isms present during the first two days, but after this the number again increased, until the colonies were uncountable. 7 It follows, therefore, that the saliva possesses a certain bacteri- cidal power which is able to deal with small quantities, or isolated organisms, but that this power is quantitative, and that it is insuffi- cient to deal with a large number. In this respect the action is similar to that of blood serum and other body fluids. It is interesting to note that pneumococci were apparently not affected by the action of the saliva, and grew from the first. Morphology.—Round, spherical or oval cocci, 0:-6—0-9 u diameter, occurring in clusters or singly and in chains, showing a slight flattening at the point of mutual apposition. Not possessed of flagella. According to Du Bary and Hueppe arthrospores are formed ; these consist of large swollen elements 1-0 to 1:5 m Wide, which stain deeply, other observers are inclined to regard such forms as degenerate cocci, and they are known also as “ involution forms.” No endogenous spore formation is known to occur. Capsule not stainable. Staining Reactions.—Retains the stain of Gram’s method, and stains easily with the ordinary basic aniline dyes, carbol methylene blue, gentian violet, &c. Biological Characters.—Non-motile, aerobic, facultative aniero- bic, chromogenic coccus, with well marked fermentative and patho- genic powers. Gelatin, 22° C.—Plates in forty-eight hours white punctate colonies, which rapidly liquefy the medium, microscopically granular, dark brown, entire. Centr. fiir Bakteriol., Bd. xX 1G91 pe Sy;