Genome DNA Sequencing, Phylogenetic Dendrogram and Outer Membrane Protein Separation Studies of Local Najaf S. Typhi Isolates/ Iraq

Abstract

From a clinically proven human typhoid cases, five S. typhi local isolates were VITIC identified and designated as: S1, S2, S3, S4 and S5. PCR for the S. typhi specific 16s rRNA genes were performed on the genomic DNA of the five isolates. Gene sequences were found as 1500 bps for the isolates S1-S4 and 1470 bps for S5. The genomic DNA similarities to standard NCBI S. typhi isolates were showing 97%, 94%, 82%, 98% and 99% corresponding to S1, S2, S3, S4 and S5 respectively. The phylogenetic dendrogram showed S5 is more identical to S3 by genetic distance 5.284 and combined into one root. The outer membrane protein was separated, purified and identified as 55 kDa and 62 kDa on SDS – PAGE. Such molecular weights were comparable to S. typhi OMP. The pure made OMP preparation is being suggestive for the; sero-diagnosis , vaccine candidate and herd immunity studies of human typhoid.