Poster Presentation Australian Society for Microbiology Annual Scientific Meeting 2022

Wastewater-based monitoring reveals geospatial-temporal trends for antibiotic-resistant bacterial pathogens in Sydney, Australia, from 2017 to 2019 (#132)

Zillur Rahman 1 , Weijia Liu 2 , Lara Stapleton 2 , Nikki Kenters 2 , Dewa Rasmika Dewi 1 , Ori Gudes 2 3 , Helen Ziochos 4 , Stuart J Khan 5 6 , Kaye Power 7 , Torsten Thomas 1 , Mary-Louise McLaws 2 5
  1. Centre for Marine Science and Innovation, School of Biological, Earth and Environmental Sciences, UNSW Sydney
  2. School of Population Health, UNSW Sydney
  3. Built Environment, UNSW Sydney
  4. Department of Microbiology and Infectious Diseases, NSW Health Pathology, Liverpool, NSW, Australia
  5. UNSW Global Water Institute, UNSW Sydney
  6. School of Civil and Environmental Engineering, UNSW Sydney
  7. Sydney Water, Parramatta, NSW, Australia

Antimicrobial resistance (AMR) is one of the top ten global health threats and current surveillance programs rarely monitor it outside the healthcare setting. This limits our ability to understand and manage the spread of AMR in the general community. Wastewater testing has the potential to simply, reliably and continuously survey trends in AMR outside the healthcare setting, as it captures biological material from the entire community. To establish and evaluate such a surveillance system, we monitored wastewater for four clinically significant pathogens across the urban area of Greater Sydney, Australia. Untreated wastewater from 25 wastewater treatment plants (WWTPs) covering distinct catchment areas encompassing a total of 5.2 million residents was sampled between 2017 and 2019. Isolates of extended-spectrum beta-lactamases (ESBL) producing Enterobacteriaceae were consistently detected, suggesting their endemicity in the community. Carbapenem-resistant Enterobacteriaceae (CRE), vancomycin-resistant enterococci (VRE), and methicillin-resistant Staphylococcus aureus (MRSA) isolates were only occasionally detected. The flow normalized relative (FNR) ESBL load was positively correlated with the proportion of the population between 19 to 50 years of age, completion of vocational education and the average length of hospital stay. Collectively, these variables explained a third of the variance of the FNR ESBL load, indicating further, yet-unidentified factors as contributor to distribution. About half of the variation in the FNR CRE load was explained by the average length of hospital stay, showing healthcare-related drivers. Interestingly, variation in the FNR VRE load was not correlated to healthcare-related parameters, but instead to the number of schools per 10,000 population. Our study provides insight into how routine wastewater surveillance can be used to understand the factors driving the distribution of AMR in an urban community. Such information can help to manage and mitigate the emergence and spread of AMR in important human pathogens.