IMPROVED ANTIBIOFILM ACTIVITY OF CIPROFLOXACIN LOADED IN EUDRAGIT E100 AQUEOUS DISPERSIONS AGAINST FLUOROQUINOLONE-RESISTANT Pseudomonas aeruginosa.

CORTI M; COLQUE CA; MANZO R; SMANIA AM; ALOVERO F

Buenos Aires

Congreso; REUNIÓN CONJUNTA DE SOCIEDADES DE BIOCIENCIAS 2017; 2017

Rising antibiotic resistance and declining development and approval of new drugs motivates approaches to increase the efficacy of existing antibiotics. Previously we reported that fluoroquinolones-containing Eudragit E100 aqueous dispersions exhibit enhanced bactericidal effect against multidrug-resistant P.aeruginosa in planktonic state. However, P.aeruginosa is an opportunistic pathogen with ability to form biofilms, which are inherently resistant to both antimicrobial agents and host defenses, causing serious problems in the chemical, medical and pharmaceutical industries. Therefore, there is a significant need to develop alternatives to prevent biofilm formation and, more importantly, to disperse or eradicate preattached biofilms. The aim of this work was to evaluate the effect of Ciprofloxacin-containing Eudragit E100 aqueous dispersions (EuCl-CIP) on biofilms of P.aeruginosa formed in Mueller-Hinton broth with standardized bacterial inoculum (106 CFU/mL) and incubated at 37o C for 48h. The remaining metabolic activity after 24 h of treatment exposure was quantified (490 nm) using the tetrazolium salt XTT reduction assay. For comparative purposes, the effect of free-drug polymer aqueous dispersions (EuCl) and some concentrations of ciprofloxacin (CIP) were evaluated simultaneously. Both EuCl and CIP showed partial reduction of cell viability in a concentration-dependent manner. However, the effect was increased when mature biofilms were treated with EuCl-CIP. The biofilm matrix of P.aeruginosa contains a high proportion of alginates, among other components. The positive charges present on Eudragit E100 would be interacting with such components causing alterations in matrix integrity and making CIP more accessible into biofilm. Using the Eudragit E100 cationic polymer as carrier for antimicrobials is an effective strategy to enhance the efficacy of the drugs on bacterial biofilms, in addition to their effect on planktonic cells.