Degrading Vibrio cholerae Biofilms with Bacteriophage and potential combined effect of phage and antibiotic on biofilms

Abstract

Vibrio cholerae is a gram-negative coccobacillus known as the causative agent of cholera- a gastrointestinal disease endemic to developing and underdeveloped countries, Bangladesh being one of them. The ability to form biofilms made it very difficult for many broad host range antibiotics to penetrate through them and destroy them completely. The cells in the biofilm can persist in a wide range of environmental conditions by remaining metabolically dormant and able to resuscitate into planktonic cells after getting suitable opportunities which can lead to a cholera outbreak. Antibiotics have been used to breakdown biofilms, however the attempts remained unsuccessful in most cases even if the concentration is a few times higher compared to the planktonic counterpart of the same bacteria. In this study, bacteriophage therapy was introduced as an alternative to antibiotic treatment for degrading V. cholerae biofilms. Combined treatment of phage and antibiotic (kanamycin) was performed to check the effectiveness in degrading biofilms and killing the planktonic bacteria at the same time. In both cases of single phage and combination treatment there were evidence of decreasing the biofilm layers of Vibrio strains but not when treated with kanamycin alone. Shiga Toxin producing E. coli (STEC) was used to screen the phage’s ability to target hosts other than Vibrio strains, which turned out to be ineffective. There is potential scope to use combined phage and antibiotic therapy in regulating biofilm formation, but further investigation and risk evaluation is required