Role of CSE1034 in Escherichia coli Biofilm Destruction

Abstract

Present study was conducted to assess the effect of ethylenediamine tetraacetic acid (EDTA); a non antibiotic adjuvant, and CSE1034, a novel antibiotic adjuvant entity in biofilm destruction of Escherichia coli, and comparing the efficacy with other drugs. We first determined the susceptibility of six antimicrobial agents against planktonic cultures, as well as sessile cells of E. coli clinical isolates, using the Clinical and Laboratory Standards Institute (CLSI) method. Subsequently, effects of EDTA alone, and drugs on bacterial curli production, adhesion, and in-vitro biofilm destruction were studied. The percentage of biofilm persistence was determined with spectrophotometry. The structural damage of biofilms was studied by scanning electron microscope. It was found that, among the drugs used, CSE1034 was the most effective against all of the E. coli clinical isolates, with MIC and MBEC values ranging from 32-64 µg/ml and 256-512 µg/ml, respectively. Exposure of clinical isolates with EDTA alone caused inhibitions of curli formation and bacterial adhesion at 4 to 5 mM. Further, EDTA treatment of preformed biofilm caused complete biofilm destruction at 8-10 mM. Interestingly, CSE1034 due to presence of 10 mM EDTA led to enhanced antibacterial, as well as biofilm destruction activities. Results of spectrophotometric analysis and scanning electron microscopy revealed that approximately 92% biofilms were eradicated by the CSE1034, and not by comparator drugs. The results indicate that the CSE1034 appears to be most effective drug of choice for the treatment of infections caused by E. coli.