Antibiotic Resistance Gene Reservoirs in a Sewage-Impacted Coastal Environment

Date:

Thursday, 23 January 2020

Time:

11.30am – 12.30pm

Venue:

Conference Room 1, Level 10
Tahir Foundation Building (MD1)
Saw Swee Hock School of Public Health
National University of Singapore
12 Science Drive 2, S(117549)

Synopsis:

Since their discovery in the 1940s, therapeutic antimicrobials have ushered in a golden age of unprecedented human health. These antimicrobials are largely antibacterials or antibiotics as defined by the World Health Organisation (WHO). However, use, overuse and misuse of antibiotics in human and animal health and food production has accelerated an adaptive antibiotic resistance (AbR) response in bacterial populations. The association between antibiotic use and resistance is extremely complex, involving numerous factors such as: human behaviour in diverse settings (e.g. hospitals, agriculture); transmission of pathogens and resistance genes between humans, animals and the environment; migration of people and food; and human and animal waste disposal. Consequently, the WHO and its member states, including Australia, are calling for a One Health approach in which stakeholders across various disciplines within the human, animal and environmental domains collaborate. Recent collaborative research involving my laboratory has investigated the influence of stormwater input on the abundance of AbR genes in estuaries and beaches in Sydney. Genes conferring resistance to a variety of antibiotics were found to increase by up to 102-fold above normal levels following major rainfall events (typically those >50 mm) that result in raw sewage overflow into the stormwater system. Resistance genes to clinically important antibiotics including the last resort carbapenems and vancomycin were detected. In Australia, people readily use coastal aquatic environments for recreational purposes such as bathing, fishing or water sports. Additionally, wildlife and companion animals interface with coastal environments. These contaminated environments represent an exposure risk to humans and a transmission pathway for (re)introduction of circulating or, newly captured AbR genes from environmental bacteria into the community. This research calls for further interdisciplinary research to determine the risk of AbR gene pollution to coastal water users.

About the speaker:

A/Prof Labbate is an internationally-recognised researcher in antimicrobial
resistance and infectious disease. Regarding the former, he is particularly interested in movement of antimicrobial resistance genes between bacteria and their contamination in the wider environment thereby acting as a reservoir. Regarding the latter, A/Prof Labbate predominantly focuses on a group of marine bacteria called Vibrio species that cause disease in humans (e.g. diarrhoeal disease such as cholera) and marine animals (e.g. aquaculture diseases).

He has extensive experience and knowledge in the bacterial process of lateral gene transfer, a phenomenon that facilitates the emergence and evolution of bacterial pathogens and their resistance to antimicrobials.

His work spans multiple disciplines and is focused on the interface that microbes have with their environment and how this drives disease processes (e.g. how environmental parameters lead to disease outbreaks by Vibrio pathogens) or evolution/emergence of pathogens (e.g. selection pressure and lateral gene processes driving emergence of virulence and antimicrobial resistance).