In Vitro activity of EDTA and Kojic Acid against biofilm forming Micro-Organisms causing Catheter-associated Urinary Tract Infections

Abstract

Device associated infections account for the majority of nosocomial infections; hence 95% of nosocomial urinary tract infections are catheter associated. Biofilm formation on the urinary catheter accounts for the persistence of CAUTIs. Recently various methods of biofilm control are being developed to overcome the complications of prolonged use of antibiotics such as antibiotic resistance which is widely spread among hospitalized patients. One of these methods is the use of metal chelators that render the biofilm environment less convenient for the survival of microorganisms. In this study we tested the effect of EDTA, Kojic acid and their combination to verify their effectiveness as biofilm inhibitors that could be used to coat urinary catheters and inhibit biofilm formation from the start. This study was conducted from August 2017 till January 2018 on eighty four patients from Intensive care units of Ain Shams University hospitals were enrolled in this study, from which 52 isolates causing CAUTIs were obtained. Most of the samples were collected from the surgical ICU 37 (71.2%), followed by Internal Medicine ICU 11 (21.2%) and the Geriatric ICU 4 (7.7%).The bacterial isolates were tested for their ability to form biofilm by inoculum preparation, washing, fixation, staining and interpretation of the results by detecting their optical density (OD) of each well stained with crystal violet and measured at 620 nm using a Micro titre plate reader (Tecan. Infinit F50).