SPECIAL FORMS OF CONJUNCTIVAL INFECTION 209 



subcutaneous cellulitis, also in orbital inflammations arising from the adjoining 

 sinuses. Concerning the finding of Streptococci in the endogenous infections of 

 the eye, see p. 368. 



Cultures. A facultative anaerobe. On agar small round grey surface colonies, 

 slightly stippled, transparent. They generally have sharper margins than the 

 colonies of Pneurnococci, and have very little tendency to coalesce. 



On ascites agar they grow better, and their borders often have fine radial 

 striations. 



In bouillon the growth is variable sometimes a fine cloudiness, sometimes clear, 

 with a more or less free deposit, which often collects into balls, and can only be 

 broken up by vigorous shaking. 



Milk is coagulated after a few days. On potatoes there is at most a scanty 

 growth sometimes, indeed, none at all. 



In a gelatine stab-culture at 18 C., fine granules form along the track of the needle 

 without liquefaction ; a grey growth, with a smooth, wavy, or indented border, 

 spreads slowly out on the surface. 



The chains, which are most easily seen in preparations from bouillon, vary in 

 length and in form in different strains. Behring, von Lingelsheim, and others, 

 have subdivided the organism on this basis l into Sir. brevis, with short chains, diffuse 

 clouding of bouillon, a suspicion of liquefaction in gelatine, growth on potatoes, and 

 generally low virulence ; and Sir. long us, with long chains, giving a deposit at the 

 bottom of the clear bouillon, no liquefaction of gelatine, no growth on potatoes, and 

 greater virulence. This division cannot be rigidly carried out, and the subdivisions 

 attempted by other authors (Lenhartz and Schottmuller) are not recognized. 

 Zangermeister considers that the puerperal and the saprophytic Streptococci are 

 the same, and that an exaltation of virulence is possible (Centr. f. Bakt., Ref., 

 1907, p. 468). 



Schottmuller attempted a differentiation of the Streptococci by their growth on 

 blood-agar. The Sir. erysipelatis sew longus, the highly pathogenic form, shows 

 here a definite haemolysis, a clear circle being formed around the individual white 

 colonies. The Sir. mitior seu viridans which is not pathogenic or only slightly so, 

 grows as a green or brown smear, without any definite haemolysis. The capsulated 

 coccus (Sir. mucosus) forms a glutinous slimy grey-green scum. The Pneumo- 

 coccns develops a dark grey pigment, without any haemolysis. 



Many observers are agreed that the pathogenic forms alone have a hsemolytic 

 action (cf. Baumann, Mi inch. med. Woch., 1906, No. 25). Others, however, deny 

 this ; the formation of pigment is also variously stated. It is certainly worth 

 noting these points in the findings in the eye. 



There is no constant difference to be made out by the use of different kinds of 

 sugars, although many strains of virulent Streptococci constantly cause fermentation, 

 while the Pneumococcus and the Sir. mucosus do not. 



The virulence of the Streptococcus is very variable ; it is best retained in a 

 gelatine culture, which, after two days in an incubator at 22 C. is preserved in an 

 ice-chest. The pathogenicity for man does not always coincide with that for 

 animals. Strains which have become highly pathogenic by passage through animals 

 cannot always be at once u%ed for the production of immune serum, suitable for 

 the treatment of human beings. Individual strains vary much in their power to 

 produce antibodies, so that a serum obtained from one strain does not always 

 immunize to the same extent against other strains. We have, therefore, the prepara- 

 tion of polyvalent sera (Menzer's serum by Merck, Hoechst's antistreptococcal 

 serum, and those of Ahronson and Moser, prepared from strains obtained fresh from 



1 For literature, cf. v. Lingelsheim, Kolle and Wassermann, 'Handbook,' vol. ii., and 

 Gunther, ' Bacteriologie,' 1906, sixth edition, p. 735. 



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