BACTERIAL IDENTIFICATION USING SSRA ENCODING TRANSFER-MESSENGER RNA.

Abstract. Ribosomal DNA (rDNA) sequences are widely used for phylogenetic and bacterial identification. However, rDNA of different species often reveals similar or identical same sequences. This study employed the bacterial stable small RNA (ssrA) gene encoding transfer-messenger RNA (tmRNA) as a tool for identification of Staphylococcus aureus, Enterococcus spp, Pseudomonas spp and Enterobacteriaceae from clinical isolates as representative groups using PCR and species specific primers. The method correctly identified 11 standard strains and 99 clinical isolates. Quantitative PCR revealed a limit of detection of 10(-5) µg of DNA for S. aureus and Enterococcus spp, and 10(-6) µg for Pseudomonas spp and Enterobacteriaceae. Further studies with a greater number of bacteria especially from clinical samples will need to be undertaken before this bacterial molecular marker can be applied in a clinical setting.