PUS-PRODUCING MICROORGANISMS 85 



Streptococcus Pyogenes. The cocci which grow in chains, 

 streptococci, must now be considered. There are many 

 varieties, but the Streptococcus pyogenes (the pus-producing 

 streptococcus) is the only one that need be considered. 

 This organism gives rise chiefly to the spreading inflamma- 

 tion, such as erysipelas, cellulitis, and septicemia. It may 

 cause a localized abscess. It is a rapidly growing organism 

 when conditions are suitable, and is the commonest cause 

 of puerperal infection. It frequently attacks the blood and 

 causes a solution of the red cells. When streptococci attack 

 serous membranes, peritoneum, pleura, heart lining or 

 meninges the infection is very severe and the mortality high. 

 It is commonly present in the mouth, and may produce 

 tonsillitis. It is not so widespread in its distribution as the 



FIG. 27. Streptococcus pyogenes. (Abbott.) 



foregoing coccus, but is greatly feared in surgical and 

 maternity wards. Streptococci are capable of producing 

 inflammation of many sorts and no tissue of the body seems 

 able to resist them when of sufficient virulence. They most 

 commonly affect the tonsil, heart lining, lung, and subcu- 

 taneous tissue. Disinfection of materials from streptococcic 

 infections should be done by carbolic acid, bichloride, or 

 hydrogen peroxide. Great care is necessary in the handling 

 of dressings, clothing, and utensils from patients with strepto- 

 coccus infections, because, despite the low resistance of the 

 organism, transmissions take place quite easily, and it is 

 highly probable that it always occurs by direct transference 

 of the germs as they live a very short time exposed to light 

 and air. This is particularly true of puerperal infections, 



