Comparative_transcriptome_analyses_of_pBSSB2_postitive_and_negative_Salmonella_Typhi

Bacteria regulates flagellin expression via phase variation, In Salmonella enterica, this process allows the expression of one of two flagellin genes, fliC or fljB locus, one at a time. S. Typhi possesses only the fliC gene (H:d) and lacks the fljB locus, therefore, is not capable of phase variation. However, some S. Typhi strains isolated exclusively from Indonesia have a fljB homologue located on a novel linear plasmid pBSSB1, that encodes a novel flagellin, H:z66. PBSSB2 (a derivative of pBSSB1 with a kanamycin resistant cassette) has been transferred into and stably maintained in S. Typhi (BRD948) and E.coli (Top10). Furthermore, the expression of the z66 flagella antigen is expressed in the transformed S.Typhi BRD948. To date, pBSSB1 is the first non-bacteriophage-related linear plasmid to be described in enterobacteriacea1; we propose that a comparative transcriptome analyses of pBSSB2+ and pBSSB2- strains of S. Typhi BRD948 strains may reveal genetic information providing clues to the functional role of pBSSB1-encoded genes and possible influence on S Typhi-encoded genes that may influence pathogenesis of S. Typhi.