SPECIAL BACTERIOLOGY 
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V. Disease Production, Mode of Infection, Disinfection 
and Prophylaxis 
Streptococci are widely distributed in nature, but 
usually in association with man, they are found in soil, 
water and milk. Some very severe epidemics of “strep¬ 
tococcus sore throat” have been caused by the use of 
infected milk. 
In human beings they cause both local suppurations 
like staphylococci and also septicemia (“blood poison¬ 
ing” of the laity) ; infections develop very rapidly from 
twelve hours on, and if it becomes general, produces en¬ 
docarditis (inflammation of the lining of the heart), 
meningitis (inflammation of the lining of the skull), 
childbirth fever, acute rheumatism, sore throat (tonsil¬ 
litis), osteomyelitis (inflammation of the bone-marrow), 
pneumonia (“septic” pneumonia) ; they often accom¬ 
pany other infections, e. g., diphtheria. They invariably 
enter through the skin; the prevention is surgical clean¬ 
liness, disinfection, and fumigation. 
VI. Mechanism of Infection and Immunity 
Streptococci produce endotoxins, also hemolysin 
(which destroy red blood cells). 
Immune bodies produced in infected animals are ag¬ 
glutinins, bacteriolysins and opsonins; phagocytosis is 
important in combating the infection. 
VII. Bacteriologic Diagnosis 
Gram-positive cocci, usually arranged in chains, grow 
slowly or not at all on meat extract media, but very well 
on “rich” media, cause hemolysis on blood agar plates. 
If confused with pneumococci, differentiation may be 
difficult; see section on Pneumococcus. 
