A Novel Disinfection Technology for Antimicrobial Resistance Control in Water

By Professor Hu Jiangyong

Director, Centre for Water Research
Deputy Director, NUS Environmental Research Institute

Antimicrobial resistance (AMR) poses a significant threat to public health. Resistance occurs when bacteria, fungi, viruses and parasites undergo genetic changes that protect them from the effects of antimicrobial agents. For example, proteins targeted by antimicrobial agents may undergo changes that essentially ‘hide’ them from the antimicrobial agents. Alternatively, the microbes will develop protective or repair mechanisms to circumvent the effect of the drugs. While traditionally associated with hospital-acquired infections, antimicrobial-resistant infections may also originate from environmental sources.

Microbes in the environment can develop antimicrobial resistance when they are exposed to antimicrobial agents. This may occur, for example, when antibiotics are discharged into waterways from the agriculture, healthcare and pharmaceutical manufacturing industries. The proliferation of antimicrobial-resistant microbes in water that is used for irrigation, aquaculture, or recreational activities, increases the chances of AMR infection, which may occur when individuals have direct exposure to water, soil or air contaminated with resistant microbes, or via indirect contact following the consumption of contaminated food.

This problem is exacerbated by the extensive consumption of antibiotics in developed societies. A recent report by the World Economic Forum stated that up to 90% of antibiotic doses consumed are later excreted into water bodies as active substances. [1] Despite this, modern water treatment processes are often not developed to filter out antimicrobials from water sources. Therefore, there is an urgent need for experts to develop effective measures to prevent the spread of AMR in the environment.

At the NUS Environmental Research Institute (NERI), Professor Hu Jiangyong and her research team focus on novel water treatment and reuse process development for emerging contaminant removal and control in water.

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One of their approaches is to control the spread of AMR in Singapore’s drinking water system. A cutting-edge technology known as ultraviolet light emitting diode (UV-LED) was introduced as an alternative to the traditional low-pressure UV disinfection method. In their study, Prof Hu examined the disinfection efficiency of the UV-LED on Escherichia coli (E. coli), a common microbe found in water systems that are contaminated by fecal matter or sewage. [2] The team proposed an optimal design of UV-LED arrangement for UV disinfection reactors, providing insights into future optimisations of UV LED disinfection system design.

Prof Hu and her team have also focused on UV advanced oxidation processes for years, which exhibit promising improvement in reducing concentrations of antibiotic-resistant genes (ARGs). [3] They found that the combination of UV and chlorination ensured a better control of ARGs in water. [4] In another study, the simultaneous application of UV-LED and chlorination was also found to suppress the growth of biofilm in a water distribution pipeline system, as well as the resistant microbes in the biofilm. [5] This study was supported by National Research Foundation of Singapore (NRF) and National Natural Science Foundation of China (NSFC) under the NRF-NSFC Joint Research Grant Call (Earth Science).

Prof Hu has been pivotal in the development of AMR control measures for water treatment and distribution systems. Her research has demonstrated the potential to utilise the combined processes of UV and free chlorine in water treatment and practice to control the dissemination of antibiotic resistance. Findings from her research could further enhance the quality of drinking water, by informing relevant strategies for controlling AMR in various water systems.

Prof Hu also continues to lead efforts into AMR control in the aquaculture water environment. Studies have revealed concerning levels of resistance to common antimicrobials in foodborne pathogens in aquaculture farms. Having developed a highly efficient UV-LED-based novel disinfection process, the team is well-positioned to work seamlessly with industrial partners to pilot test the technology for aquaculture farms in the tropics.

References 

  1. World Economic Forum. (2021). Antimicrobial Resistance and Water: The risks and costs for economies and societies. Geneva, Switzerland.
  2. Liu, X., Shang, X., Cai, Q., & Hu, J. (2023). Lab-and pilot-scale evaluation of bacterial inactivation and reactivation influenced by UV-LEDs arrangements in continuous flow water disinfection reactors. Journal of Water Process Engineering, 55, 104093.
  3. Ghosh, S., Chen, Y., & Hu, J. (2022). Application of UVC and UVC based advanced disinfection technologies for the inactivation of antibiotic resistance genes and elimination of horizontal gene transfer activities: Opportunities and challenges. Chemical Engineering Journal, 450, 138234. 
  4. Liu, X., & Hu, J. Y. (2020). Effect of DNA sizes and reactive oxygen species on degradation of sulphonamide resistance sul1 genes by combined UV/free chlorine processes. Journal of hazardous materials, 392, 122283. 
  5. Chen, Y., Li, Y., Yang, S., Chiang, T. Y., Zhu, X., & Hu, J. (2022). Controlling Biofilm Growth and Its Antibiotic Resistance in Drinking Water by Combined UV and Chlorination Processes. Water, 14(22), 3643.

 

HuJiangYong-scaled-square
Professor Hu Jiangyong is Directors for Research Cluster in Environmental Sustainability and Centre for Water Research in Department of Civil and Environmental Engineering at National University of Singapore specialising in the field of water treatment and water reclamation.

Contact

 

E: ceehujy@nus.edu.sg
P: +65 6516 4540
W: https://nus.edu.sg/neri/

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