98 BACTERIOLOGY 



64. M. pyogenes var. aureus Rosenbach 



I.e., No. 6. 



Morphology. Cocci 1.0 /x, in irregular clumps. Stain by Gram's method. 



Gelatin colonies. Deep: round-oval, granular, brownish. Surface: whitish 

 yellow points, becoming more yellowish ; not increasing in size, but be- 

 coming sunken in the liquefied gelatin. Microscopically, round ; border 

 undulate erose lacerate; punctate, finely granular, translucent. 



Gelatin stab. Liquefaction saccate, with a yellowish film on the surface. 

 Gelatin turbid, with a yellowish sediment. 



Agar slant. An abundant opaque, smooth, moist, glistening layer, becoming 

 bright orange. 



Potato. Growth abundant, orange, or rather scanty. 



Bouillon. Turbid, becoming clear, with abundant yellowish sediment. 



Milk. Coagulated, acid. Indol negative. H 2 S, slight. 



Glucose bouillon. No gas ; acid. 



Pathogenesis. Virulence of cultures variable. Rabbits : Subcutaneous inocu- 

 lations cause acute local inflammation and suppuration. The cocci mul- 

 tiply in the lymph spaces, and may be found within the leucocytes, and 

 also invading the capillary walls ; usually the cocci confined to the local 

 centres of suppuration. Intraperitoneal injections cause suppurative 

 peritonitis, either local or spreading, resulting in death. Subcutaneous 

 inoculations of human subjects result in local suppuration. 



Habitat. Widely distributed; in ulcerative endocarditis, osteomyelitis, and 

 a variety of inflammatory and suppurative processes in the body. For 

 etiological relations, see text-books. 



Varieties. 



Staphlococcus salivarius-pyogenes Biondi : Die path. Microorg. des Speichels, 

 Zeitsch. f. Hygiene, II, 1887, 1094. 



Micrococcus of Almquist : Zeitsch. f. Hygiene, X, 1891, 253. 



In pemphigus. Organism possesses specific pathogenic power. Almquist, by 

 inoculation of his own arm, caused bullae like those of phemphigus. 



Staphlococcus quadrigeminus Czaplewski : Centralblatt,Bakteriologie, XXV, 143. 



In many points similar to M. pyogenes-aureus . 



Diff. colonies on Ldffler's blood serum show in a short time a transparency 

 and liquefaction of the medium. Stain by Gram's method, but more easily 

 decolorized. Grows more slowly in gelatin, and forms an air bubble in 

 gelatin above the funnel of liquefaction. Pigment like aureus, but with a 

 rose-colored tinge. 



Habitat. Isolated from vaccine lymph. 



