Antimicrobial activities against biofilm formed by Proteus mirabilis isolates from wound and urinary tract infections

BACKGROUND: Bacterial species are capable of living as biofilm and/or planktonic forms. There is increasing evidence for the role of bacterial biofilm in various wound and urinary tract infections (UTIs). The aim of the present study was to evaluate the ability of the bacteria, isolated from urinary tract infections (UTIs) and wound infections, to form biofilm and correlate the role of biofilm with their antimicrobial resistance. MATERIALS AND METHODS: All the isolated bacteria were screened for their ability to form biofilm using the microtitre plate method. RESULTS: Wound isolates of Staphylococcus aureus and Enterobacter sp. had more biofilm forming capacity than the UTI isolates. Proteus mirabilis isolates were among the strongest biofilm forming bacteria and were chosen for antimicrobial study. In sub-MIC concentrations of antimicrobial agents used, ciprofloxacin was found to be the most effective in decreasing biofilm formation. On the other hand, ceftriaxone and ciprofloxacin were effective in partial removal of preformed biofilm biomass. CONCLUSION: Ciprofloxacin was more effective in killing bacterial cells especially at high antimicrobial concentrations that could be reached in urine levels and can be used in impregenating catheters.