Effect of active substances of disinfectants at the stages of biofilms formation

With the systematic exposure of disinfectants (DS) to cholera vibrions, they can adapt by forming biofilms fixed on various surfaces. The aim of the work is to evaluate the effect of DS on the stage of formation of V. cholerae O1 and O139 serogroups biofilms on biotic and abiotic substrates. Materials and methods. Combined and monobiofilms were obtained according to previously developed methods, the concentration of V. cholerae of planktonic and biofilm forms was evaluated by bacteriological method and polymerase chain reaction in real time (PCR-RV). The statistical significance of the differences in experimental data was assessed using Student criteria. Results. At the stage of cell adhesion, cholera vibrions in the combined biofilm showed resistance to the action of ethyl alcohol (10 and 20?%), chloramine (0.1 and 0.2?%) at exposure up to 20 min. The bactericidal effect, expressed in the absence of culture growth and positive results in PCR-RV, was observed in samples with the addition of hydrogen peroxide of all dilutions, ethyl alcohol (50?%) and chloramine (0.5 and 1.0?%). At the monolayer stage, resistance to the action of ethyl alcohol of all dilutions, hydrogen peroxide (0.1 and 0.2?%) was revealed at exposure up to 20 minutes. Under the action of chloramine of all dilutions and hydrogen peroxide (0.5 and 1.0?%), the absence of V. cholerae growth on agar was noted with positive values of their concentrations in PCR-RV. The effect of all DS on mature biofilms maintained the previous pattern. Abio- and biotic biofilms of V. cholerae O139 ctxAB?¬ and ctxAB+ showed resistance to ethyl alcohol of all dilutions, chloramine (0.1 and 0.2?%) at exposure up to 30 min. The bactericidal effect of hydrogen peroxide of all concentrations on abiotic biofilms of all strains and resistance of strains in biotic biofilms were noted. It is advisable to continue studying the effect of DS on vibrio cholera biofilms due to the possible «selection» of strains with increased resistance in the environment. Keywords: biofilms, stages, Vibrio cholerae, disinfectants.