Investigating the Expression of MexX, OprD, and OprM Genes in Pseudomonas aeruginosa

Abstract

Background: Bacterium Pseudomonas aeruginosa is regarded as opportunistic bacterium that is very aggressive and a potentially fatal infection for humans, especially in individuals with weakened immune system due to its adaptability to wide range of conditions.

Objectives: The main aim of this research was investigating the expressions of each of the mexX, oprD and oprM genes.

Methods: Bacterial isolates are isolated from different sources of clinical samples. 110 P. aeruginosa spp. were collected from many hospitals in Baghdad city. The identification of (50) isolates of P. aeruginosa was done biochemically and confirmed genetically by 16srRNA gene. Disc diffusion methods were carried to detect the antibiogram activity for fifteen antimicrobial agents. MIC for the antibiotic was done by serial dilution methods. evaluation the level of genes expression to each of mexX, oprD and oprM were carried by RT- PCR.

Results: The isolates distributed according to clinical sources of isolated 35 (70%) burn swabs, 10(20%) wound swabs, and 5(10) ear discharge. The results of Ct values were ranged for each mexX from 26.95 to 32.68 with main average 29.54, oprD from 20.56 to 24.98 with a main average 23.141 and oprM from 16.33 to 20.31 with main average 17.77 as compared with the reference gene Ct value rspL 11.14. MIC of gentamicin was ranged from 16 - 512 µ/ml that inhibit the growth seen of isolates.

Conclusion: mexX, oprD, and oprM genes are overexpressed compared with Housekeeping Gene