ACLIMATACIÓN DE BARROS ACTIVADOS A CLORURO DE BENZALCONIO Y DESARROLLO DE RESISTENCIA A ANTIBIÓTICOS

FERRO OROZCO A.M.; MORALES URREA D.A.; CONTRERAS E.M.

Congreso; XXXVII Congreso Interamericano Virtual de Ingeniería Sanitaria y Ambiental; 2021

Bacterial resistance to antibiotics is one of the most serious problems worldwide. Related to this problem is the use and discharge of large volumes of disinfectant solutions from hospitals and various industries. These compounds are diluted after their discharge resulting in sub-inhibitory concentrations, which also leads to increased resistance to antibiotics (the result of co-resistance). Among the most used disinfectants are quaternary ammonium compounds (QACs), and within this group is benzalkonium chloride (BAC). In this context, the objective of this work was to study the acclimation process of the activated sludge community in the presence of a sub-inhibitory concentration of BAC (25 mg / L) using consecutive batch assays (25 days of operation) and an open respirometric technique. Biodegradation of BAC and the decrease in active biomass were studied. Susceptibility to BAC and the antibiotics Cephalexin (CF), Ciprofloxacin (CP), and Ampicillin (AM) were monitored during consecutive batch assays at different times (0, 16, 25 days). The exposure of the activated sludge microbial community to successive additions of a sub-inhibitory concentration of BAC caused a significant decrease in the biomass concentration (44%). The remaining biomass during the acclimation process to BAC showed an increase in the resistance to two of the three antibiotics analyzed. These results indicated that prolonged exposure times to BAC are not necessary to increase microbial resistance to the antibiotics studied, which generates serious health and environmental problem.