72 CITY MILK SUPPLY 



The other streptococcus was isolated in one outbreak, from a cow in 

 the suspected herd and was different from hemolytic udder streptococci 

 in the same herd and from those of the herd in outbreak A. 



The udder of this cow had been injured and one quarter which was 

 inflamed gave a thick curdy product; the three other quarters were 

 apparently unaffected but the milk from the inflamed quarter did not give 

 hemolytic streptococci in the cultures, whereas the mixed sample of milk 

 from the three quarters that seemed sound contained human streptococci. 

 This type was wholly identical with streptococci from the throats of three 

 human cases, one of them fatal, and in another outbreak it was isolated 

 from mixed milk. This organism is now regarded as the usual cause of 

 septic sore throat and is referred to as the /3 hemolytic streptococcus of the 

 Smith type or briefly as the Smith streptococcus. The strains studied 

 differed slightly among themselves, as to form of the colonies and othei 

 cultural characteristics. On horse-blood agar plates the colonies formed 

 a sharply defined, clear, transparent, completely hemolyzed, colorless 

 zone 2 to 4 mm. in diameter; they were simple and biconvex and never 

 complex. In bouillon the growth of the several strains varied from a 

 well-clouded suspension with flocculent sediment to a perfectly clear 

 bouillon with abundant fleecy sediment. The great clouding was associ- 

 ated with the shorter chains. In 7 days, cultures in milk coagulated on 

 heating. In bouillon after 24 hr. incubation, the chains were composed of 

 round flattened cells, that is, with the transverse axis the greater with 

 occasional cells that were elongated. This streptococcus fermented 

 dextrose, maltose, saccharose, lactose and salicin with the production of 

 acid, but did not ferment mannit, raffinose or inulin. Injected intraven- 

 ously into rabbits in a definite, uniform dose it produced a febrile reaction 

 lasting 1 to 4 days or over a week, followed by, or accompanying, a local- 

 ization affecting the hip, shoulder, knee, wrist, and foot. In the more 

 acute cases foci occurred in the kidneys and heart. These streptococci 

 were identical with streptococci that were held by other bacteriologists 

 to be causative of the epidemics of septic sore throat in Boston in 1911, and 

 Baltimore and Chicago in 1912 which were found to be identical with each 

 other. 



The streptococci that have caused the recent outbreaks of septic sore 

 throat are alike in that immediately around the colonies is produced a clear 

 hemolyzed area on blood agar plates; but these hemolytic colonies are to 

 be carefully distinguished from the colony of the common throat coccus, 

 which has a partly discolored and hemolyzed mantle between the colony 

 proper and the outer, narrower hemolyzed zone. 



Study of Krumwiede and Valentine. This work was amply con- 

 firmed by Krumwiede and Valentine who investigated an outbreak of 

 septic sore throat that occurred at Rockville Center, Long Island, N. Y., 

 in June, 1914. The infection was on the route of a dairy that daily 



