Antimicrobial and antifouling efficacy of urinary catheters impregnated with a combination of macrolide and fluoroquinolone antibiotics against <i>Pseudomonas aeruginosa</i>

<p>The incidence of catheter associated urinary tract infections (CAUTIs) is increasing worldwide. This study was designed to modify a biomaterial by impregnating a silicone urinary catheter with combination of a macrolide, azithromycin (AZM) and a fluoroquinolone, ciprofloxacin (CIP). Drug release profiles showed slow yet continuous release of antibiotics from catheters for one month. <i>In vitro</i> efficacy testing showed that group B catheters [3% (w v<sup>−1</sup>) CIP + 6% (w v<sup>−1</sup>) AZM] outperformed group A catheters [2% (w v<sup>−1</sup>) CIP + 5% (w v<sup>−1</sup>) AZM] by (1) showing larger zones of inhibition (>31 mm) compared to group A (<28 mm) for up to 30 days against <i>Pseudomonas aeruginosa</i> PAO1; (2) killing adhered bacteria in 24 h compared to 24–48 h in group A; (3) showing longer antimicrobial durability for four weeks; and (4) exhibiting a stable real-time shelf life of one year, suggesting that these catheters can be explored in clinical settings, especially in long-term CAUTI.</p>