Evaluation of two novel biofilm-specific antibiotic resistance genes in clinical Pseudomonas aeruginosa isolates

Abstract

The ability of Pseudomonas aeruginosa to form biofilm plays significant role on its pathogenesis in susceptible hosts. One of the best known clinically relevant consequences of biofilm-specific properties is wide range of drug-resistance, and therefore extremely difficult to cure infections. Several mechanisms account for antibiotic resistance in biofilms, some are well-recognized and some remain to be clearly understood. Objective: The present study aimed to evaluate the role of two novel genetic loci, PA2070 and PA5033 genes, on biofilm-specific antibiotic resistance of P.aeruginosa isolates. Methods: From Jun to November 2017, one hundred clinical isolates of P.aeruginosa were collected from patients admitted to Imam Reza and Sina hospitals of Tabriz city. Biofilm formation was assessed by 96-well flat-bottomed microtiter plate assay. Biofilm-producer isolates were further investigated by polymerase chain reaction (PCR) and real-time PCR in both biofilm colony and planktonic cultures. Results: The expression analysis revealed overexpression of PA2070 and PA5033 genes in biofilm mode in comparison to planktonic cells by a mean factor of 4.33 for PA2070 and 4.733 for PA5033 gene. Moreover, statistical analysis revealed correlation between overexpression of mentioned genes in biofilm cultures (p<0.05). However, no statistically significant association was found between PA2070/PA5033 genes and planktonic isolates.