Pneumococcus conjunctivitis / by Fred T. Tooke.

  • Tooke, Fred T.
Date:
[1906]
Catalogue details

Licence: In copyright

Credit: Pneumococcus conjunctivitis / by Fred T. Tooke. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

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    them from other diplococci. As soon as the inflammation subsides the typical pneumococci disappear while the so-called Xerosis bacilli and siJaphylococci may remaifi in vaiying numbers, A mixed infection is not frequently the case and at the crisis of an attack a pure culture of pneumococci is generally found. Examining, microscopically, a section of the conjunctiva aifected by this form of inflammation, one finds a diffuse infiltration of leucocytes through the section while pneumococci can be detected in the epithelium and in the more superficial layers of the mucosa. Culture growths show a characteristic form, and the disposition towards chain formation is apparent, sometimes confusing them with the streptococcus growth. A microscopical examination of a smear preparation usually solves the problem; the diplococcus is generally seen a pair of enclosed cocci some of which are of larger size than others. The typical shape, or that most frequently seen is somewhat pointed at the poles, or lanceolate, and this characteristic is particularly v- ell seen in smear preparations. One may also observe shorter and rounder diplococci with isolated short, plump chains, as well as short bacillus-like growths and involution forms. The capsule misleads one in considering them to be as large as the staphylococci or the strep- tococci. This capsule is best seen in a preparation of Loeffler's aniline blue. Pneumococci grow only in high temperatures, over 22°C., best at 35°C.; they become weak at 40°C. They require media which are mildly alkaline, yet difi'erent gi-owths seem to vary in this respect. The media should be moist and not too old; on agar and blood serum one notices glassy, bright, opalescent colonies which are round, re- sembling tiny droplets. They are very small and not very much elevated or sharply defined. After a few days' growth these colonies disappear or are indistinct. Some colonies of pneumococci growing on a very moist surface have to be examined with the aid of a magnifying glass in order to be detected. Romer had advocated rabbit's blood serum, to which one-third glycerin has been added, as the best culture medium upon which to grow the pneumococcus. These bacteria from the conjunctiva seem to be more difficult to grow than those obtained from the sputum of pneumonia; the best media are carefully prepared blood serum and agar. Tlie cultures generally die in the incubaijor in a few days; anairobic gro^Hhs generally last a little longer and their power of virulence is also retained, as I have already stated in Gilford's conclusions. Bouillon growths produce a slight turbidity which quickly clears up. Growths from the conjunctiva