Molecular identification and sequencing of pseudomonas aeruginosa virulence genes among different isolates in al-diwaneyah hospital

Abstract

Pseudomonas (P.) aeruginosa possesses a variety of the virulence factors that may contribute to its pathogenicity, such as exotoxin A (toxA) and exoenzyme S (ExoS). The principal aim of this study was to find out the rapid method for identification of P. aeruginosa and to detect the toxA, exoS and 16SrRNA genes by Polymerase Chain Reaction (PCR) technique. Other aim on the other hand, the DNA sequencing was performed for phylogenetic tree analysis of 16SrRNA gene in local pathogenic P. aeruginosa isolates in comparison with NCBI-Genbank global P. aeruginosa isolates and finally submission of the present isolates in NCBI-Genbank database. According to the detection of the 16S rRNA gene, the study revealed that 29 (58%) and 32 (64%) of P. aeruginosa out of 50 swabs obtained from each wound and burn areas were positive. whereas in addition, the result of this study showed that the toxA gene was detected in 77% of P. aeruginosa isolated from the wound and 51% of P. aeruginosa isolated from the burn. whereas, the exoS gene was detected in 69% of P. aeruginosa isolated from the wound and 49% P. aeruginosa isolated from the burn. BLAST analysis showed that the 16S rRNA gene shared more than 99% homology with the sequences of P. aeruginosa. Furthermore, the phylogenetic tree analysis of the 16S rRNA gene indicated that (PA-IQw and PA-IQb) the 16S rRNA gene shared higher homology with other four P. aeruginosa isolates available in the GenBank. The homology of the nucleotides was between 99.9% and 100%.