INDIVIDUAL FEATURES OF PYOGENIC BACTERIA. 109 



2. The Microeoccus pyogenes tennis (Rosenbach). The 

 -Ificrococcus tetragenus is sometimes found associated with 



the foregoing two varieties in abscesses or in pus cavities, 

 and are also able to produce abscesses at the place of injec- 

 tion in animals. 



3. The Streptococcus pyogenes is found associated with the 

 staphylococci in purulent accumulations, and is sometimes 

 itself responsible for pus-production in the body. 



4. The gonococcus is the cause of specific suppuration of 

 the urethra and often elsewhere in the body.. 



5. The pneumococcus is often found in abscesses which 

 occur in the course of the disease in pneumonic patients. 



6. 7, and 8. The Bacillus pyocyaneus, typhosus, and tuber- 

 culosis are sometimes the cause of pus-production, as pure 

 cultures of these organisms have been found in some cases 

 of abscesses during the respective infections. 



Nearly all pyogenic organisms are facultative anaerobics. 



THE INDIVIDUAL FEATURES OF THE PYOGENIC 

 BACTERIA. 



I. Staphylococcus Pyogenes Aureus. 



The Staphylococcus pyogenes aureus, by far the most fre- 

 quent pus organism, is found a. in health on the surface of the 

 skin, also of the mucous membranes in the digestive tube, 

 and upper part of the respiratory tract, and 6. in pathological 

 conditions in pus irrespective of its localization, either alone 

 or in association with the other pyogenic staphylococci, also 

 in the blood in cases of general infection, and a number 

 of cases of extensive suppurating lesions, abscesses, suppu- 

 rating tumors, furuncles, etc.; and c. outside of the human 

 body in the air, in dust, and occasionally in water. 



Morphology. The Staphylococcus pyogenes aureus is a 

 small rounded cell having a diameter of 0.9 to 1.2 mikrons, 

 found either singly or in irregular groups or masses resem- 

 bling a bunch of grapes, hence its name. Sometimes it is seen 

 in pairs, as a diplococcus. Its appearance in pus as well as 

 in culture-media is the same in general as is seen in Fig. 47. 



