Effects of azithromycin on Pseudomonas aeruginosa isolates from catheter-associated urinary tract infection

Abstract

<i>Pseudomonas aeruginosa</i> is a common pathogenic bacterium in urinary tract infections (UTIs), particularly catheter-associated UTIs. The aim of this study was to investigate the effect of azithromycin (AZM) on <i>P. aeruginosa</i> isolated from UTIs. Isolates were identified by biochemical assays and the Vitek system. Antimicrobial susceptibility was determined using the disk diffusion assay. Biofilm formation and adhesion were assayed using a crystal violet staining method. The swimming motility was assayed on agar plates. The elastase activity and rhamnolipid production were determined by the elastin-Congo red method and orcinol reaction, respectively. A total of 32 bacterial isolates were collected from 159 urinary catheters and eight of them were <i>P. aeruginosa</i> isolates. The results showed that the <i>P. aeruginosa</i> isolates had stronger biofilm formation capability and the biofilms were thicker than those of <i>P. aeruginosa</i> PAO1. AZM inhibited biofilm formation and adhesion on urinary catheters, and also decreased swimming motility and the production of virulence factors. The results of this study indicated that AZM is potentially a good choice for use in the treatment of UTIs.