Just after sunset each night, little penguins waddle to their nests in the breakwater by St Kilda Pier in Melbourne, Australia. The iconic – and downright adorable – sight attracts tourists, but for parasitologist and associate professor Michelle Power, the penguins can also reveal important information about the marine ecosystem.
“They’re an iconic species, but they’re declining in parts of Australia,” Power says. “They’re at the top of the food chain, so they give an indication of what’s going
on in the overall ecosystem.”
Power researches reverse zoonoses – when pathogens jump from humans to animals – at Australia’s Macquarie University. The most concerning and widespread reverse zoonosis is antibiotic (or antimicrobial) resistant bacteria – one of the greatest threats to human health globally.
“These bacteria are ‘weeds’ in wildlife microbiomes – they carry genetic traits that have been amplified by humans and should not be there,” explains Power.
Power has recorded these bacteria in animals from the remote Australian bushland to the barren Antarctic wilderness. But animals living in and around urban areas, such as St Kilda’s little penguins, are most likely to have it.
To learn how much antibiotic-resistant bacteria the penguins harboured, Power collected 448 samples of poo from wild and captive colonies in St Kilda and in Phillip Island across the bay. Alarmingly, Power found antibiotic-resistant bacteria in 3% of the wild population, and 45% of those in captivity.
“The closer the populations get to human habitation, the higher frequency of antimicrobial-resistant genes. When you get into captivity, you can imagine that on the extreme end,” says Power.
Animals can be exposed to the bacteria through sewage, direct human contact and medical waste. But, Power explains, more research is needed to understand how these superbugs impact animals, and how they’re transmitted. “That’s what we’re trying to nail down, now we know there’s so much out there. We keep finding antimicrobial resistance in places we weren’t expecting.”
Surveying environments for superbugs can require many hands and, since 2018, she’s been recruiting citizen scientists to help collect possum poo for her aptly named initiative: Scoop a Poop. She’s received more than 2,000 samples so far and found more than 29% of brush-tailed possums carry the bacteria.
“It’s about educating people around the issues of antimicrobial resistance. They can help us fight this issue by understanding what’s happening in the environment.”
So, what can we do to help stop our superbugs from spreading? “The best thing is to find a toilet, and not go naturally when out hiking. And take your rubbish.”
Main image: Michelle Power examines bacteria in the faecal matter of species. © Doug Gimesy