PUS-PRODUCING MICROORGANISMS 83 



This color-producing organism is called the Staphylococcus 

 pyogenes aureus (the golden pus-producing coccus). See 

 Plate II for an idea of growth and color. It is about ^^^75- of 

 an inch across and appears under the microscope as single 

 individuals, pairs, but more frequently in grape-like groups. 

 It stains fairly well with most dyes used. It does not form 

 spores and does not move from place to place by its own 

 power. It grows best about 85 F. It is killed about 56 C. 

 or 130 F. at ten minutes in the moist condition, but when 

 completely dry it may require boiling to kill. When dried 

 on cloth or paper it may live three months. This organism 

 grows well on ordinary laboratory foodstuffs and produces, 

 particularly in the presence of diffuse light and oxygen, a 

 golden yellow color. This coccus has the property of coagu- 

 lating milk and liquefying gelatin by the ferments it pro- 

 duces. It is killed by corrosive sublimate, 1 to 1000, in ten 

 minutes in watery solution. In pus a considerably longer 

 time is required. 1 to 20 carbolic kills in one minute; 1 to 

 500 in about one-half hour. The pus in which the staphylo- 

 coccus lives supplies a protective envelope, and should be 

 well mixed and diluted with the germicide. 



This organism is very virulent for the smaller animals, 

 which may be infected by rubbing on or injection under the 

 skin. It will then produce a local abscess or septicemia. It 

 may produce acute inflammation of the interior of the heart, 

 or bone disease. 



Staphylococcus Pyogenes Albus. The Staphylococcus pyo- 

 genes albus is precisely like the foregoing except that it does 

 not produce the golden-yellow pigment, but grows in a por- 

 celain-white manner. There is an organism on the skin to 

 which we give the same name, but add the word "epider- 

 midis." It is constantly present dn the surface, in the epider- 

 mis, and in the glands of the skin. Since its pus-forming 

 ability is so feeble, "pyogenes" may be omitted and the 

 name Staphylococcus epidermidis albus given. It does not 

 produce disease, but is of constant annoyance in making 



