Genetic Identification of Pseudomonas aeruginosa Virulence Genes among Different Isolates

Background and objectives: Pseudomonas aeruginosa possesses a variety of virulence factors that may contribute to its pathogenicity. P. aeruginosa also has a large number of virulence factors such as exotoxin A, exoenzyme S, nan 1 and Las genes. The aim of this study was to evaluate oprI, oprL as reliable factors for rapid identification of P. aeruginosa and to detect toxA, exo S, nan1 and LasB genes by Polymerase Chain Reaction (PCR). Materials and methods: In this study 30 isolates of P. aeruginosa were recovered from burn, pulmonary tract and blood infections. Results and conclusions: The oprI and oprL genes were detected in all of 30 P. aeruginosa isolates collected. The presence of toxA gene in isolates from burn and pulmonary tract was significantly higher than that from blood. All tested isolates harbored LasB gene. However, difference between exoS prevalence in isolates from pulmonary tract and burn isolates was statistically significant higher than that from blood. The prevalence of nan1 gene was significantly higher in isolates of pulmonary tract and burn specimens than isolates from blood. Molecular methods have been reported to be superior to the phenotypic methods for identification of P. aeruginosa by designing a multiplex PCR assay based on oprI and oprL genes for molecular detection of P. aeruginosa Determination of different virulence genes of P. aeruginosa isolates suggests that they are associated with different levels of intrinsic virulence and pathogenicity. Significant correlations between some virulence genes and source of infections indicates implementation of infection control measures will help in controlling the dissemination of virulence genes among P. aeruginosa isolates.