Background: Pseudomonas aeruginosa is one of the important causes of hospital infections septicemia, in patients hospitalized in burn ward and those with cystic fibrosis. Considering the PAPI-2 important role in bacteria pathogenesis, the aim of this study is to investigate the frequency of the encoding genes exoU and xerC as markers of PAPI-2 from isolated environmental and clinical samples.

Materials and Methods: In this descriptive study, 40 isolates from sewage of burn wound hospital and 30 from patients hospitalized in burn ward of the hospital covered by shahid Beheshti University, respectively. The frequency of PAPI-2 in both environmental and clinical strains was detected by using PCR and the primers exou and xerc.

Results: Of 40 studied environmental pseudominas aeruginosa strains that their genus and species were confirmed by chemical tests, 30 samples (75%) consisted of exoU gene and 32(80%) included xerC gene. Also, of 30 isolated strains of burn patients, 23 isolates(76.7%) contained both exoU and xerC gene. The results revealed a high prevalence of PAPI-2 (90%) between clincial and environmental samples of pseudomonas aeruginosa.

Conclusion: With due attention to the results, information reveal that the importance and prevalence of pathogenicity island type 2 were high in Iranian clinical and environmental Pseudomonas aeruginosa isolates. Also, considering all environmental isolates have at least one of genes, we should care about the risk of transporting pathogenic strains and find solutions to control it.