Home > Understanding and Reducing the Spread of Antibiotic Resistance in Disinfection

Understanding and Reducing the Spread of Antibiotic Resistance in Disinfection

Project Number # 2079

Understanding and Reducing the Spread of Antibiotic Resistance in Disinfection

Background:

Antibiotics have been widely used for human and livestock to treat infectious diseases and promote the growth of livestock (Zhuang et al., 2015). Although the effectiveness of antibiotics has significantly benefited mankind, the intensive use of antibiotics has led to the spread of antibiotic resistance among microorganisms. Antibiotic resistance genes (ARGs), as the main reason for microorganisms to be able to withstand the bacteriostatic or bactericidal effects of antibiotics (Martínez et al., 2014), have been widely found in soil, surface water, groundwater, and even deep ocean sediments (Allen et al., 2010; Brown and Balkwill, 2009; Ouyang et al., 2020). The spread of ARGs not only posed a global threat to the public well-being, but also affected the development of industries such as veterinary medicine and agriculture (Teuber, 2001).

Wastewater treatment plants (WWTPs) have been recognized as the hotspots of ARGs and antibiotic resistance bacteria (ARB) (Mao et al., 2015). The disinfection treatments play an important role as critical barriers to mitigate the transfer of ARGs and ARB (Singer et al., 2016). However, the effect of various disinfection processes on the ARGs diversity and abundance has not been adequately investigated. Therefore, it is quite important to understand the fate of ARGs and ARB under various disinfection processes to identify the optimal disinfection conditions for reducing the spread of antibiotic resistance in Australia.

Aims:

This project aims to understand and reduce the spread of antibiotic resistance in disinfection. This project will utilize 16S rRNA sequencing, qPCR and metagenomics to uncover the changes in the occurrence, abundance and diversity of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) under various disinfection processes. This study will help identify the optimal disinfection conditions for reducing the spread of antibiotic resistance. In addition, based on the results of this study, the control and management strategy for antibiotic resistance will also be proposed.

Significance:

This project is significant because it will comprehensively reveal the fate of ARGs and ARB under various disinfection processes and identify the optimal disinfection conditions for reducing the spread of antibiotic resistance. This project will also provide a state-of-the-art approach for accurate estimation of occurrence, diversity, abundance and fate of ARGs.

  • This project will potentially deliver a social benefit. According to World Health Organization (WHO), antibiotic resistance has become one of the biggest threats to global health and food security (WHO, 2017). Furthermore, the Australian government also realized the significance of this issue and developed the Australia’s first national antibiotic resistance strategy (Australian Government Department of Health Department of Agriculture). The strategy outlines seven objectives to achieve the goal of minimizing the development and spread of antibiotic resistance. Therefore, this project will deliver a strong social benefit by revealing the fate of ARGs and ARB during various disinfection processes and identifying the optimal operating conditions for reducing the spread of antibiotic resistance.
  • This project will potentially deliver an environmental benefit. The ARB/ARGs present in the disinfected water will potentially pose an adverse effect on the receiving environment such as the river or lake. Therefore, this project will deliver a strong environmental benefit by identifying the optimal disinfection conditions for reducing the spread of antibiotic resistance.
  • This project is innovative in its approaches. This multi-disciplinary project will integrates the advanced multi-omics analyses with innovative process engineering. The advanced multi-omics analyses will provide strong support for this project.

Research plan:

The project will consist of two interlinked tasks.

Task 1: Changes in the occurrence, abundance and diversity of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in various disinfection processes (Months 1-24)

This task will reveal the changes in the occurrence, abundance and diversity of ARGs and ARB in various disinfection processes.

The water samples before and after various disinfection processes will be collected at different seasons from the water authority which sponsors this project. Afterwards, the occurrence, abundance and diversity of ARGs and ARB will be analysed using the methods described below.

DNA from the water samples will be extracted for 16S rRNA sequencing to uncover the profiles of ARB, and high-throughput qPCR will be applied to determine and quantify the occurrence of typical ARGs for these water samples. These ARGs will include tetracycline resistance genes (tetA, tetG, tetM, tetX, tetQ and tetW), erythromycin resistance genes (ermB and ermF) and sulfonamide resistance genes (sulI and sulII). They were selected according to types of antibiotics and main resistance mechanisms. In addition, some selected mobile genetic elements (MGEs) represent the potential of the horizontal gene transfer, including the class 1 integrase gene (intI1), the conjugative transposon Tn916-Tn1545 family (Tn916/1545) and one insertion sequence common region I gene (ISCR1) will also be quantified to (HGT). Furthermore, some water samples before and after disinfection will also be selected for high-throughput metagenomics. This approach will be applied to investigate the fate of the broad-spectrum profiles of ARGs in disinfection.

Task 2: Control and management strategy for antibiotic resistance (Months 25-36)

Based on the results of this study, the control and management strategy for antibiotic resistance will also be proposed.

References:

Allen, H.K., Donato, J., Wang, H.H., Cloud-Hansen, K.A., Davies, J., Handelsman, J., 2010. Call of the wild: antibiotic

resistance genes in natural environments. Nat. Rev. Microbiol. 8 (4), 251-259.

Australian Government Department of Health Department of Agriculture, Response to the threat of antimicrobial resistance, Australia’ first national antimicrobial resistance strategy, 2015-2019. ISBN: 978-1-76007-191-2.

Brown, M.G., Balkwill, D.L., 2009. Antibiotic resistance in bacteria isolated from the deep terrestrial subsurface. Microb. Ecol. 57 (3), 484.

Mao, D., Yu, S., Rysz, M., Luo, Y., Yang, F., Li, F., Hou, J., Mu, Q., Alvarez, P.J.J. 2015. Prevalence and proliferation of antibiotic resistance genes in two municipal wastewater treatment plants. Water Res., 85, 458-466.

Martin, M., 2011. Cutadapt removes adapter sequences from high-throughput sequencing reads. EMBnet J. 17, 10-12.

Ouyang, W., Gao, B., Cheng, H., Zhang, L., Wang, Y., Lin, C., Chen, J., 2020. Airborne bacterial communities and antibiotic resistance gene dynamics in PM2.5 during rainfall. Environ. Int. 134, 105318.

Singer, A.C.  Shaw, H.  Rhodes, V.  Hart, A.2016. Review of antimicrobial resistance in the environment and its relevance to environmental regulators Front. Microbiol., 7, 1-22.

Teuber, M., 2001. Veterinary use and antibiotic resistance. Curr. Opin. Microbiol. 4 (5), 493-499.

Zhang, T., Yang, Y., Pruden, A. 2015. Effect of temperature on removal of antibiotic resistance genes by anaerobic digestion of activated sludge revealed by metagenomic approach. Appl. Microbiol. Biotechnol., 99, 1-9.

Zhuang, Y., Ren, H., Geng, J., Zhang, Y., Zhang, Y., Ding, L., Xu, K., 2015. Inactivation of antibiotic resistance genes in municipal wastewater by chlorination, ultraviolet, and ozonation disinfection. Environ. Sci. Pollut. Res. 22 (9), 7037-7044.