Analysis of antibiotic resistance gene expression in pseudomonas aeruginosa by quantitative real-time-PCR

Pseudomonas aeruginosa is one of the most common nosocomial pathogens with high mortality rates. Organisms such as Pseudomonas aeruginosa have the ability to develop high level MDR (Multi drug resistance). The MexX gene is one of the largest gentamicin resistant efflux pumps. Aim of study For better understanding of the antibiotic resistance mechanism in P. aeruginosa,it was conducted to determine the expression of the gene encoded these efflux pumps in 54 isolates of P. aeruginosa isolated from patients admitted to various hospitals in Baghdad/ AL-Kharkh side using qRT-PCR, were selected based on their gentamicin susceptibility pattern. Antibiotic disk diffusion method was performed for gentamicin. Finally, qRT-PCR was used for determining the efflux pump genes expression related with gentamicin resistance. Among seven isolation sources , the burns showed greatest resistance (100%, n = 14) while the urine iolates was lowest (50%, n = 2) as shown table (II). Most of isolates (88.8%, n = 48) exhibited efflux pump MexX gene but different expression was observed in different isolates.. In addition, there was high level of MexX gene expression in burn and the lowest was to hospital equipment isolates. Identifying the bacterial resistance mechanisms is very complicated. Although efflux pump MexX gene plays an important role in antibiotic resistance in P. aeruginosa, because of acting the efflux pumps on antibiotics in a non-specific manner. It is elusive to describe an antibiotic resistance based on the presence or absence of an efflux pump genes.