The serologic structure of Lac+ recombinants of 2a, 2b, 5a and var. Y serotypes of Sh. flexneri was compared. Rec. 2a Lac+, rec. 2b Lac+ and rec. Y Lac+ were shown to be identified, and rec. 5a Lac+ was found to differ from those mentioned in that it was deficient in determinants for 3,4 group antigen complex. Furthermore, the paper discusses the presumable genetic mechanisms of the described variability.
All Keywords