STREPTOCOCCI 6 I 



amount of suppuration that occurs than do staphylococcic lesions, and the pus 

 is more serous in character. 



Some cases of broncho-penumonia, meningitis and angina are caused by 

 streptococci. Streptococci are widely believed to be the specific cause of 

 erysipelas; they are the common cause of puerperal septicemia, and though it is 

 very doubtful, some believe they are the specific cause of scarlet fever, in which 

 disease they are usually found present in the mouth and throat.* 



Though not generally accepted at this time, one must bear in mind the teach- 

 ings of Rosenow that streptococci may mutate and become pneumococci and 

 vice versa. Rosenow strongly believes that the location of streptococci when 

 they have entered the human body and the character of the disease which fol- 

 lows is determined by the particular strain of streptococcus infecting; different 

 strains manifesting more or less constant selectivity or predilection to attack 

 special organs or tissues, e.g., one strain will affect the appendix, another the 

 heart, another the stomach, etc. 



Rosenow and others believe epidemic poliomyelitis is caused by streptococci. 



DIAGNOSIS 



Erysipelas and other inflammatory conditions, where pus is scant or absent, 

 usually show some edema; by making a small incision in an appropriate place 

 serous fluid may be obtained with a sterile capillary tube. From this several 

 smears are. made. These are stained and examined and will usually be found 

 sufficient to establish the diagnosis in doubtful conditions caused by strepto- 

 cocci. However, organisms may not be found in the smears, or the morphology 

 may be such as to make it impossible to say whether streptococci or pneumococci 

 were observed; then it is desirable to make cultures. The fluid is obtained from 

 the lesion with a sterile capillary tube and planted on several tubes of media 

 agar, blood agar, Loeffler's blood serum or other media. These tubes are in- 

 cubated at 37C. for 24 to 48 hours, and the growth examined both macroscopic- 

 ally and microscopically. Pus and sputum are examined for streptococci in 

 the same way. 



Where streptococcus bacteremia exists or is suspected, blood cultures must 

 be made. The method of obtaining blood and inoculating media is the same as 

 when making blood cultures for staphylococci, previously described. 



Streptococci arranged in pairs rather than chains and sometimes encapsu- 

 lated, so that they are indistinguishable from pneumococci under the micro- 

 scope, are occasionally found, most often in examination of blood and sputum. 

 Differentiation requires culture. 



Inulin bouillon is fermented by pneumococci, not by streptococci; pneumo- 

 cocci form dry, blackish colonies on blood-agar without hemolysis; streptococci 

 form whitish or greenish colonies with or without hemolysis; pneumococci grow 

 in the sterile bouillon filtrate from strep'tococcus cultures, streptococci do not. 



* See " Further Experiments with a Streptococcus Isolated from Cases of Acute Rheuma- 

 tism," Beattie, J. M., Journal of Pathology and Bacteriology, April, 1910. 



"The Etiology of Erysipelas and Allied Infections," Panton and Adams, The Lancet, 

 Oct. 9, 1909. 



