3 1 . Streptococcus 



The incidence of flagellated streptococci may not be as rare 

 as it is commonly considered to be. Bacteriologists rarely examine 

 a culture of cocci for motility, assuming it to be nonmotile. All 

 flagellated streptococci studied to date fall in Lancefield group 

 D, or the enterococcus group. 



Three strains of motile streptococci were studied, one from Dr. 

 O. Felsenfeld, Hektoen Institute, Chicago; and two from Dr. Hans 

 Graudal, Statens Serum Institut, Copenhagen, Denmark. 



Flagellar Characteristics 



All three strains studied showed good motility and were well 

 flagellated (see Fig. 33). The Felsenfeld strain showed a few 

 fairly long chains while the Graudal strains showed mainly diplo- 

 cocci and rarely chains of as many as four individuals. In the 

 Felsenfeld strain the individual organisms showed mainly one 

 flagellum, occasionally two. The flagella appeared to originate 

 most frequently at the point of division of two cells which may 

 indicate a polar origin. The Graudal strains were definitely multi- 

 trichous with up to five flagella on a single cell. In these strains 

 the flagella were definitely of polar origin in most instances. If 

 one should characterize the flagellation in the usual terms the 

 streptococci studied should probably be labeled polar multitri- 

 chous. If this is correct these streptococci are the only gram-posi- 

 tive bacteria with polar flagella ever encountered by the author. 



The shape of the flagella in the three strains studied was mainly 

 normal with unusually long wavelength, similar to Sarcina ureae. 

 The normal wavelength of the three strains averaged 3.2 microns. 

 In the Graudal strains were found a number of flagella which were 

 partly curly. The wavelength of the curly waves averaged 1.2 

 microns. There was also found a rare flagelhim with a wavelength 

 about 2.4 microns which correspond to the subnormal type seen 

 more distinctly in Sarcina ureae. The small amplitude shape seen 

 in Sarcina was not found, nor were any other shapes found. In 

 general, the shapes of the flagella of streptococci and Sarcina are 

 quite similar and both types of cocci have normal flagella of 

 distinctly longer wavelength than the great majority of rod shaped 

 bacteria. 



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