Welcome to my Twitter presentation for #WallingfordECRTweets !

I’m Holly, a 4th-year @ExeterMed PhD student in @CEH_ecotox group @UK_CEH. I’m researching the effects of pollution on antimicrobial resistance in bacteria in aquatic organism intestines (their microbiome). (1/12)

Antimicrobial resistance (or #AMR) occurs when microbes are exposed to an antibiotic (or antifungal) that harms or kills them; microbes mutate or acquire DNA that allows them to survive future antibiotic exposures. (2/12)

Why does #AMR matter?

Drug-resistant infections are costly, complicated & can be fatal. They kill at least 700k people/year. ‘Review on Antimicrobial Resistance’ predicted 10mil deaths/year by 2050 if no action is taken (see https://amr-review.org/ ). (3/12)

So how does #AMR occur in the environment?

Antimicrobials are found in animal meat production, cleaning products, personal care products, pest control, agriculture & industry. The environment receives waste from all these antimicrobial uses, driving environmental AMR (4/12)

The big Q...

Does environmental #AMR matter to us?

YES!

The environment is arguably the source of AMR—a natural phenomenon worsened by overuse & pollution of antimicrobials. Humans & pets interact with the environment in many ways relevant to AMR transmission(5/12)

Now we know environmental #AMR matters, how can we MEASURE/MONITOR/TACKLE it?

With our reliance on it, interaction with it and its role as pollution endpoint, the aquatic environment seems a good place to start! (6/12)

When microbes in rivers are exposed to pollution, they might need to develop resistance to survive. We can measure the extent to which this occurs using lab, field and in-situ studies. (7/12)

Environmental AMR is usually measured by taking sediment & water at a particular time & place, which tells us nothing about what happens between sampling.

Alternatively, we can study microbes living in aquatic wildlife—animals that have chronic exposure to pollutants. (8/12)

THIS is what my research focuses on, working with freshwater fish & shrimp (Gammarus pulex). I’ve analysed the microbiomes (i.e., all the bacteria) in these organisms from field experiments & lab exposures. See the picture below for more info on how I process samples! (9/12)

Recently, I exposed freshwater shrimps (G. pulex) to levels of an antibiotic found in the Riv Thames. Could these low levels of antibiotic select for resistant genes in the bacteria & affect their microbiomes? “Effect” can be measured in many ways – genes are just 1 way. (10/12)

I also looked at which bacteria within the microbiome were impacted most by the antibiotic exposure. Are these changes in the composition of the Gammarus microbiome important for their health, function & reproduction? We don’t know yet. See the picture for more detail! (11/12)

That’s all folks! Thanks for reading my Twitter presentation for #WallingfordECRTweets !

I’d like to thank my supervisors, @OxonAndrew @WillHGaze and @JohnsonAjo for all their support, and my funders @NERCscience and @GW4plusDTP

Feel free to ask me any Qs! (12/12)