276 



SPECIFIC MICRO-ORGANISMS 



are readily obtained on all the common media and growth occurs 

 between 9" and 42°, best at 37° C. Broth is diffusely clouded 

 with abundant sediment. In gelatin stab-culture, growth occurs 

 all along the line of inoculation with funnel-shaped liquefaction 

 (Figure 109). On agar slant the growth is con- 

 fluent and yellowish after 24 hours. There is 

 similar growth on Loffler's serum, often with 

 liquefaction of the medium. 



The staphylococcus is relatively resistant to 

 heat and chemical germicides. It is killed at 

 62° C. in ten minutes and at 70° C. in five 

 minutes. V. Lingelsheiim^ found it more re- 

 sistant, requiring ten minutes at 80° C. and 

 an hour at 70° C. to kill his strains, but his 

 figures cannot be accepted without further con- 

 firmation.^ It is about as resistant to chemical 

 poisons as any of the sporeless bacteria, and 

 is commonly employed as a test object in the 

 investigation of germicides. Mercuric chloride 

 i-iooo requires three to five hours to kill staph- 

 ylococcus cultures and much longer if the 

 organisms are present in pus. Carbolic acid, 

 3 per cent, kills them in two to ten minutes. 

 Fig. 109.— Gelatine ^^^ pigment is a lipochrome and is pro- 

 culture Ste^/jyfococcMi duced only in the presence of oxygen. The 



oMyeas one week old. . ,. r , i-rr , r .1 11 1 ■ 



tryptic ferment diffuses out of the cells and is 

 capable of liquefying gelatin, albumen and fibrin. The staphy- 

 lococcus produces a soluble poison which kills leukocytes 

 (leukocidin) and others which dissolve red blood cells (staphy- 

 lolysin) and cause clumping of red blood cells (agglomerin). 

 These substances are true soluble toxins and they are destroyed 

 by heating to 80° C. Other soluble poisons seem also to be pre- 

 sent. The bacterial cells killed by heat are only slightly toxic, 



' Neisser: KoUe und Wassermann, Handbuch, 1912, Bd. IV, S. 361. 

 ^ Compare with similar tests on streptococci by v. Lingelsheim, p. 273. 



