Investigation of reduction in risk from antibiotic resistance genes in laboratory wastewater by using O₃, ultrasound, and autoclaving

Abstract

Biological laboratory wastewater containing both antibiotic‐resistant bacteria (ARB) and antibiotics is a potential source of antibiotic resistance genes (ARGs). Thus, we determined the efficacy of autoclaving, a common disinfection method, in eliminating 5 ARGs (sul1, sul2, tetW, tetM, amp) and the integrase‐encoding gene intI1 from laboratory wastewater. Autoclaving (15 min, 121°C) inactivated all bacteria including ARB, whereas ARGs persisted in the wastewater with limited reduction even after 60 min of treatment. Ozonation (O3), ultrasound (US), O3/US, and autoclaving followed by O3 were investigated for their ability to reduce ARGs in laboratory wastewater. With O3 and O3/US, the reduction rate ranged from 5.44 to 7.13 log for all ARGs investigated. Wastewater treatment with US alone did not reduce ARGs under the present experimental conditions (150 W, 53 kHz). Among the four treatments, autoclaving followed by O3 treatment showed the highest reduction rates in the shortest time; however, further optimization and investigation are needed for the advanced treatment of bio‐laboratory wastewater. Overall, this study provides novel insights into ARG sources and demonstrates that advanced oxidation methods can be useful to optimize laboratory wastewater treatment for ARG inactivation. Practitioner points Bio‐laboratory wastewater is potential reservoir of ARGs. Conventional autoclaving was not able to reduce ARGs to a low level. Autoclaving‐O3 completely eliminate all the bacteria. Autoclaving‐O3 reduced ARGs efficiently (6.12–7.86 logs removal in 60 min).

Effective control of antibiotic resistance using a sonication-based combinational treatment and its application to fresh food

“…At present, various physical treatments (e.g., ultraviolet radiation, heat, and cold plasma) have been proposed as solutions to control various foodborne pathogens, including ARB, in the food system [8] , [9] . For example, recent studies have reported that a combination of physical treatments may lead to the synergistic inactivation of various pathogenic bacteria, including Escherichia coli , Listeria spp., and Staphylococcus aureus [9] , [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] . However, during bacterial inactivation, nucleic acids can be released from the dead bacteria into the food environment.…”

“…However, the development of technologies to control various antibiotic resistance factors related to ARB is often neglected. Although some studies have been conducted to monitor ARB distribution and reduce the horizontal gene transfer (HGT) of released ARGs, strategies to inactivate both ARB and ARGs have not been widely studied so far [6] , [17] , [18] , [22] , [23] , [24] , [25] .…”

Disinfection of polymicrobial urines by electrochemical oxidation: Removal of antibiotic-resistant bacteria and genes

“…In literature, chlorine has been reported that may lead to initially attack proteins and peptidoglycan bound to the cell wall and the cell membrane and, subsequently, penetrate into the cell wall to reach cytoplasm and react with nucleic acids [3,63]. Additionally, not only chlorine but also ozone has been recently reported for its ability to destroy ARGs [64][65][66]. Ozone reacts with bacterial functional groups, such as amines or amino acids, and also attacks proteins, peptidoglycan and liposaccharides in the cell envelope [67,68].…”

Assessment Impacts of Ozone on Salmonella Typhimurium and Escherichia coli O157:H7 in Liquid Dairy Waste

“…As a result, the ozone-oxygen mixture stopped all the bacterial strains present [74]. Ozone treatments have also been proved to reduce antibiotic resistance genes and pathogenic bacteria in wastewater [73][74][75][76][77].…”