Yafteh

Background: Pseudomonas aeruginosa has emerged as one of the most important nasocomial pathogen resulting in morbidity and mortality rates.

The aim of this research was to PCR identification of P. aeruginosa isolated from tracheal samples based on the amplification of I lipoprotein (oprI) for detection of genus and L lipoprotein (oprL) for detection of species and Exotoxin A (toxA) gene.

Materials and Methods: A total of 120 P. aeruginosa clinical isolates were collected from patients with tracheal infections. Chromosomal DNA of the isolates was extracted and used for PCR of oprI, oprL and Exotoxin A (toxA).

Results: From 120 P. aeruginosa 100% were positive for oprI and oprL genes based on PCR assay and from these samples 83% were positive for ExotoxinA (toxA).

Conclusion: Using PCR method with genome and specific primers can be more accurate and sensitive than biochemical tests to identify P.aeruginosa strains. It is also replaceble method for biochemical methods.

According to the results obtained by PCR test toxA gene is not as sensitive as oprI and oprL to recognize P. aeruginosa. So using PCR of all these three genes are necessary to detecte this bacterium.