| dc.description.abstract | With the increased use of disinfectants due to the Covid-19 pandemic an increased understanding of their effect on antimicrobial resistance is of paramount importance. This study looks at the effect low concentrations of the disinfectant benzalkonium chloride (BAC) have on the minimum inhibitory concentration (MIC) of antibiotic tetracycline (TEC). A laboratory-scale sludge reactor was used to investigate if there is a correlation between low concentrations of benzalkonium chloride and the minimum inhibitory concentration of both tetracycline and benzalkonium chloride. During two experiments, two aerobic sludge reactors were maintained for 4 weeks, one containing low levels of BAC and the second one functioning as a control reactor. During the first experiment, a concentration of 2,0 mg/L BAC was added to the test reactor. In the second experiment, this concentration got raised to 10 mg/L. The effects of BAC on the MIC and microbial populations were examined. The effect on the microbial community was determined using total suspended solids (TSS) and volatile suspended solids (VSS). Both the MIC values and the results from the TSS and VSS suggest that subinhibitory levels of benzalkonium chloride led to a higher resistance to benzalkonium chloride. The MIC value for tetracycline resistance however indicate that benzalkonium chloride did not affect the resistance of the microbial community. The MIC values for tetracycline seemed to be stable and didn’t get influenced through the expose to benzalkonium chloride. These results indicate that overuse of a disinfectant can lead to resistance to these products leading to a decrease in their effectiveness. Despite the fact that in this study disinfectant use did not affect the resistance to tetracycline, more research needs to be conducted to obtain a better understanding of the effect of disinfectants on antibiotic resistance. | |
