Suggestion to supplement Shigella flexneri classification scheme with the subserovar Shigella flexneri 4c: phenotypic characteristics of strains.

A new serovar of Shigella flexneri has been isolated with increasing frequency in the USSR. It has the antigenic formula IV:7,8. We suggest that it be incorporated into the classification scheme as S. flexneri subserovar 4c. The 212 strains of this proposed subserovar examined to date display biochemical and serological properties typical of the species, are sensitive to the genus-specific bacteriophage, and cause keratoconjunctivitis in the Sereny test.