Oral Presentation Australian Society for Microbiology Annual Scientific Meeting 2018

Towards a one health approach: dissemination of antibiotic resistant microbial communities and genes from hospital, municipal wastewater to downstream environments (#6)

Barbara Drigo 1 , Jan Bell 2 , Gianluca Brunetti 1 , Xiayuan Wu 1 , Samuel Aleer 1 , Michael Short 1 , Rietie Venter 3 , Enzo Lombi 1 , Erica Donner 1
  1. Future Industries Institute, University of South Australia, Adelaide, SA, Australia
  2. The University of Adelaide, Adelaide, SA, Australia
  3. School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, Australia

Municipal wastewater is emerging as an ideal composite matrix for monitoring human and environmental phenomena on a community scale. Systematic analysis of municipal wastewater has already proven useful as a means of providing population-scale information on human exposure to chemicals such as licit and illicit drugs. While very much an emerging field, wastewater monitoring could in future be envisaged to deliver valuable population health outcomes such as facilitating early-onset warning of infectious disease outbreaks. Here, we monitored the emergence of antibiotic resistance and opportunistic human pathogens by sampling wastewater from hospitalized, healthy populations, wastewater treatment plants and reclaimed water in South Australia. We used a combination of DNA based high throughput sequencing and quantitative methods (digital droplet PCR and qPCR), and phenotypic screening of opportunistic pathogens and antibiotic resistant bacteria, fungi and protozoa. Results showed that important resistance genes such as NDM, oxa-48, VIM, SME and qnrS were significantly more abundant in municipal wastewater treatment influents than in hospital-specific wastewater sources. Targeted resistance gene analysis indicated that problematic and emerging resistance threats, such as methicillin resistant Staphylococcus aureus, KPC-producing bacteria, and plasmid-mediated resistance to colistin are already widespread in community wastewater, and in some cases putatively more prevalent in the general community than in hospitalized patients. Recycled water entering the reuse pipelines was of demonstrably high quality with IntI-1, blaTEM, vanA, qnrS, sul1 and ctx-m 32 all below detection by standard qPCR analysis, however digital droplet PCR analysis was sensitive enough to detect residual antibiotic resistant genes and to follow their regrowth potential. This research gives insight into the opportunities and complexities of using municipal wastewater for microbial risk surveillance.