8TAPHYLOCOCCUS INFECTIONS. 543 



This was confirmed by Lubarsch, who found the 

 condition most readily, produced in the chicken 

 and with more difficulty in the mouse, rabbit and 

 dog. It rarely results if suppuration is avoided. 

 Killed cultures may be used. 



Eabbits and mice are the most susceptible ani- suscepti- 

 raals. The susceptibility of man is much greater. Animals. 

 The organisms are most virulent for rabbits when 

 injected intravenously, and a variety of lesions 

 may result, as abscesses in various parts of the 

 body (especially the kidney, heart and muscles), 

 arthritis, endocarditis, etc. They are less patho- 

 genic when injected into the pleural or peritoneal 

 cavities. Eabbits are rarely to be infected by the 

 feeding of cultures. In experimental infections 

 degenerations of the axis cylinders in the white 

 and gray matter, and of ganglionic cells, have been 

 noted. The virulence of staphylococci is subject 

 to great variations, and it may be increased by 

 passage. In passing a culture through the rabbit 

 eight times, v. Lingelsheim reduced the fatal dose 

 for rabbits from 5 c.c. of a 24-hour broth culture, 

 to 1/100 c.c., but a corresponding increase in viru- 

 lence for the mouse and guinea-pig did not occur. 

 Virulence for animals is not a reliable index of 

 virulence for man. 



The staphylococcus is the most common pus infections 

 producer in man. The most frequent infections 

 are those of the skin, the organisms gaming en- 

 trance through the hair follicles rather than 

 through the sweat ducts (Unna), resulting in such 

 conditions as acne pustules, abscess of the skin 

 and subcutaneous tissue, furuncles and carbun- skin. 

 cles. They are found almost constantly in the 

 lesions of impetigo and often in pure culture, 

 Thev have been much vaunted as a cause of 



