SO LOCALIZED INFECTIONS OF PUS NATURE 



into pus is called suppuration, which may be defined 

 as the destruction of tissues and cells by the products 

 of bacteria. Pus under the microscope is composed of 

 white blood cells, particularly the so-called polynuclear 

 leukocytes, microorganisms, and partly or wholly 

 destroyed tissue. There is also some granular 

 fluid. 



While the term pus is applied to all the degenerated 

 products of inflammation, there is a special word when 

 the material collects on a surface. This is usually desig- 

 nated as an exudate. For example, the false membrane 

 of diphtheria is called an exudate as is also the fluid 

 containing shreds within the pleural or abdominal 

 cavities, or in the lungs in pneumonia. 



PUS-PRODUCING MICROORGANISMS 



It has been stated that there is no particular germ 

 alway responsible for pus, but there is a small group 

 of the round bacteria most commonly present. They 

 are called micrococci or staphylococci, and strepto- 

 cocci. Certain members of the group of cocci may also 

 do other things than produce simple pus or abscesses. 

 These will be considered at the end of this chapter. 

 Bacteria other than cocci which can produce pus are 

 the colon bacillus, pyocyaneus bacillus, typhoid bacillus, 

 pseudodiphtheria bacillus. 



Staphylococcus Pyogenes Aureus. Of the micrococci 

 there is one particular species of importance which 

 by some bacteriologists has been divided into two on 

 account of its ability to produce color in laboratory 

 cultures and because the one having a golden yellow 



