title: Antigenic variability of Shigella flexneri serovars 1-5.
abstract: Data on the genetic basis of the classification of Shigella flexneri serological variants 1-5 are presented. Subserovars "a" are related to monolysogenic variants of the basic lipopolysaccharide (LPS) structure 0 antigen 3,4, "b" to bilysogenic ones. A scheme of their antigenic variability, with regard to loss of one or both prophages is presented. This scheme helps differentiate between antigenic variability and mixed or superinfections. Recent reports confirming our previously published suggestion to exclude serovar 6 (Shigella newcastle) from Shigella flexneri are analyzed. We propose that antigenic variability of S. flexneri 1-5 results from lysogenization of naturally occurring strains. The possibility of consecutive lysogenization of S. flexneri y (-:3,4) by bacteriophages 6 and 7 has been shown, as exemplified by the circulation of a previously unknown subserovar IV:7,8.
mesh_terms: D000942:Antigens, Bacterial / Q000235:genetics / Q000276:immunology*; D001435:Bacteriophages / Q000235:genetics; D008242:Lysogeny; D010957:Plasmids; D012763:Shigella flexneri / Q000145:classification / Q000235:genetics / Q000276:immunology*; D013045:Species Specificity
chemical_list: D000942:Antigens, Bacterial