Special Seminar on Water and Wastewater Microbiology

       On 16 November 2018, Chulabhorn Research Institute held a special seminar on two presentations entitled “The (not so) odd couple – enteric human viruses and free-living amoeba co-existing in complex water matrices” and “Interactions between Arcobacter and free-living amoebae in wastewater” by Dr. Mats Leifels and Mariem Oloroso, both visiting from the School of Public Health, University of Alberta in Edmonton, Canada. Professor Emeritus Dr. Skorn Mongkolsuk, the Director of Laboratory of Biotechnology at CRI delivered a welcome speech for the speakers.  

       Dr. Mats Leifels presented the work being co-authored by Dr. Rafik Dey, Alyssa Wiedemeyer, and Professor Nicholas. J. Ashbolt. He summarized that the role of the ubiquitous free-living amoeba (FLA) as a reservoir of enteric bacterial pathogens in natural and artificial water bodies and an important factor in the acquisition of virulence for water-based pathogens like Legionella pneumophila are well described (Thomas and Ashbolt, 2011). At the same time, it has been shown that enteric viruses such as human Adenovirus (HAdV) could be detected in the water phase, biolithic Biofilms and Sediments –both latter are environments known as habitats of freshwater FLA such as various Acanthamoeba, Naegleria and Vermamoeba species- of an Urban River in Essen, Germany making it likely that interaction occurs in between those pathogens which have been shown to co-evolve over millions of years (Mackowiak et al., 2018). The role of FLA in the enrichment and propagation of enteric viruses such as Enterovirus or HAdV is still unclear, even though several works discussing their function as reservoirs and possible vehicles have been published over the past decade (Atanasova et al., 2018, Scheid and Schwarzenberg, 2012). The rationale of the presented study was to follow a comprehensive strategy to evaluate the concentration and integrity of infectious and heat-inactivated HAdV in feeding FLA trophozoites and dormant cysts over time under laboratory and real-life conditions. Given the previously assumed restricted host amplification of HAdV in human gastrointestinal cells, a putative propagation in free-living amoeba now introduces a confounder when interpreting the presence of this virus as an indicator for sewage-impacted waters, as well as their (and other, even more public health relevant enteric viruses’) persistence towards disinfection routinely used in waste-/drinking water treatment and water reuse. FLA cysts containing enteric viruses will also decrease the efficacy of water disinfection processes. 

  Subsequently, Mariem Oloroso presented results from her Masters Thesis work being coauthored by Dr. Rafik Dey and Prof. Nicholas J. Ashbolt. She found out that several members of the emerging pathogen family Arcobacter have been associated with at least three outbreaks of water-associated acute gastritis since 1983 (Rice et al., 1999; Fong et al., 2007; Jalava et al., 2014). A close relative of Campylobacter, itself one of the leading global causes of human gastrointestinal disease, Arcobacter can be found in high numbers in sewage and has been shown to survive the entire wastewater treatment process (Lu et al., 2015). Arcobacter is of further relevance due to its ability to co-exist within free-living amoebae (FLA), ubiquitous protozoa that are environmental reservoirs for several pathogenic bacteria (Muchesa et al., 2014).  

       The Ashbolt lab at the School of Public Health, University of Alberta is currently exploring Arcobacter’s interactions with several genera of FLA in sewage and the effects of these interactions on physical and chemical wastewater treatment processes. This organism’s ability to persist within different types of amoebae has implications on both wastewater treatment efficacy and public health (https://www.ualberta.ca/public-health/about/faculty-staff/academic-listing/nicholas-ashbolt). 

       Both speakers work under a supervision of Professor Nicholas J. Ashbolt. His research focuses on next-generation municipal water services (drinking water, wastewater, stormwater) framed around resource recovery (i.e. water, energy, fertilizers) for improved eco-health and living conditions; integrated with quantitative microbial risk assessment (QMRA) to identify research gaps and management targets. Current topics of his group include qualitative and quantitative research questions regarding water system management (treatment performance, post-treatment control of opportunistic pathogens) from a public health perspective. He has over 30 years of experience both in Academia as well as a practitioner by working with the US Environmental Protection Agency (which awarded him the Bronze Award for science at ORD in 2008, 2012 and 2013, was named the Translational Health Chair in Water by the Province of Alberta, Canada,and has more than 200 highly regarded publications, with an h-index of 43 (https://scholar.google.ca/citations?user=16x4DHYAAAAJ&hl=en). 

References: 

Atanasova, N.D., Dey, R., Scott, C., Li, Q., Pang, X.L., Ashbolt, N.J., 2018. Persistence of infectious Enterovirus within free-living amoebae – A novel waterborne risk pathway? Water Res 144, 204-214. 

Fong, T. T., Mansfield, L. S., Wilson, D. L., Schwab, D. J., Molloy, S. L., & Rose, J. B. (2007). Massive microbiological groundwater contamination associated with a waterborne outbreak in Lake Erie, South Bass Island, Ohio. Environ. Health Perspect., 115(6), 856–864 

Jalava, K., Rintala, H., Ollgren, J., Maunula, L., Gomez-Alvarez, V., Revez, J., … Pitkänen, T. (2014). Novel microbiological and spatial statistical methods to improve strength of epidemiological evidence in a community-wide waterborne outbreak. PLoS ONE, 9(8).  

Lu, X., Zhang, X. X., Wang, Z., Huang, K., Wang, Y., Liang, W., … Tang, J. (2015). Bacterial pathogens and community composition in advanced sewage treatment systems revealed by metagenomics analysis based on high-throughput sequencing. PLoS ONE, 10(5), 1–15.  

Mackowiak, M., Leifels, M., Hamza, I.A., Jurzik, L., Wingender, J., 2018. Distribution of Escherichia coli, coliphages and enteric viruses in water, epilithic biofilms and sediments of an urban river in Germany. Sci Total Environ 626, 650-659. 

Muchesa, P., Mwamba, O., Barnard, T. G., & Bartie, C. (2014). Detection of free-living amoebae using amoebal enrichment in a wastewater treatment plant of gauteng province, South Africa. BioMed Res. Int., 2014.  

Rice, E. W., Rodgers, M. R., Wesley, I. V., Johnson, C. H., & Tanner, S. A. (1999). Isolation of Arcobacter butzleri from ground water. Lett. Appl. Microbiol., 28(1), 31–35. 

Scheid, P., Schwarzenberger, R., 2012. Acanthamoeba spp. as vehicle and reservoir of adenoviruses. Parasitology Research 111, 479-485. 

Thomas, J.M., Ashbolt, N.J., 2011. Do Free-Living Amoebae in Treated Drinking Water Systems Present an Emerging Health Risk? Environ Sci Technol 45, 860-869.