Degradation Kinetics of Antibiotic Resistance Gene mecA of Methicillin-Resistant Staphylococcus aureus (MRSA) during Water Disinfection with Chlorine, Ozone, and Ultraviolet Light

Abstract

Degradation kinetics of antibiotic resistance genes (ARGs) by free available chlorine (FAC), ozone (O3), and UV254 light (UV) were investigated in phosphate buffered solutions at pH 7 using a chromosomal ARG (mecA) of methicillin-resistant Staphylococcus aureus (MRSA). For FAC, the degradation rates of extracellular mecA (extra-mecA) were accelerated with increasing FAC exposure, which could be explained by a two-step FAC reaction model. The degradation of extra-mecA by O3 followed second-order reaction kinetics. The degradation of extra-mecA by UV exhibited tailing kinetics, which could be described by a newly proposed kinetic model considering cyclobutane pyrimidine dimer (CPD) formation, its photoreversal, and irreversible (6–4) photoproduct formation. Measured rate constants for extra-mecA increased linearly with amplicon length for FAC and O3, or with number of intrastrand pyrimidine doublets for UV, which enabled prediction of degradation rate constants of extra-mecA amplicons based on sequence length and/or composition. In comparison to those of extra-mecA, the observed degradation rates of intracellular mecA (intra-mecA) were faster for FAC and O3 at low oxidant exposures but significantly slower at high exposures for FAC and UV. Differences in observed extra- and intracellular kinetics could be due to decreased DNA recovery efficiency and/or the presence of MRSA aggregates protected from disinfectants.

Inactivation of Antibiotic-Resistant Bacteria in Wastewater by Ozone-Based Advanced Water Treatment Processes

“…By comparing these results with the reports on changes in sewage flora following O 3 treatment [ 57 , 58 ], it is observed that the changes in the bacterial community structure composition are almost similar for O 3 and O 3 -based AOP treatment. The overall results suggest the importance of introducing advanced wastewater treatment for removal of AMRB and AMRGs, although some of them are not completely removed [ 103 , 104 , 105 ]. This seems reasonable considering the existence of multiple microorganisms [ 103 , 106 , 107 ] and AMRGs [ 108 , 109 , 110 , 111 ] in wastewater.…”

Metagenomic analysis of MWWTP effluent treated via solar photo-Fenton at neutral pH: Effects upon microbial community, priority pathogens, and antibiotic resistance genes

“…In contrast, recent literature points out to the spread and selection of ARB and ARGs after the application of traditional technologies such as Chlorine, ozonation and UV-C irradiation/oxidant ( Jin et al, 2020 ; Kirchner et al, 2020 ; Lee et al, 2021 ; Moreira et al, 2021 ; Sharma et al, 2019 ). In addition, ozonation and UV-C irradiated processes are energy intensive and costly, which may hinder their application in developing countries.…”

Traditional and Emerging Water Disinfection Technologies Challenging the Control of Antibiotic-Resistant Bacteria and Antibiotic Resistance Genes

“…Researchers have developed several traditional and emerging wastewater disinfection technologies to inactivate pathogenic microorganisms in wastewater (Figure ). − These technologies can be divided into light-based disinfection and non-light-based disinfection, and some have received extensive research attention. The role of traditional WWTPs is generally to effectively remove impurities in sewage, including organic matters, nitrogen, phosphorus, and metals.…”