Evaluation of Antibiotics Effectiveness Against Vibrio Cholerae under the Conditions of Complex Biofilm Formation

The effectiveness of 9 antibiotics against mono- and polymicrobial biofilms formed by Vibrio cholerae O1 strains was studied in vitro on fragments of chitinous exoskeleton of broad- fingered crayfish Astacus astacus in monoculture and together with oppor­tunistic bacteria Klebsiella spp. and non-O1/non-O139 V.cholerae. An increase in the antibiotic resistance of monomicrobial biofilms compared with planktonic bacteria was observed. Resistance of the polymicrobial biofilm bacteria to most antibacteri­al drugs corresponded to the resistance of the most stable strain in the monomicrobial biofilm. An increase in resistance to two and three drugs was observed in biofilms formed by classical toxigenic strains together with non-O1/non-O139 V.cholerae, while in biofilms formed together with Klebsiella spp. — to one antibacterial drug. Changes in antibiotic sensitivity during the interaction between bacteria in polymicrobial biofilm should be taken into account when developing tactics for prevention and treatment of infections.