Seagulls and superbugs
Recently we were advised that to stop a seagull stealing our chips and ice-creams at the seaside, we should stare at them... but a recent study also revealed that gulls are making off with something else much more serious, and this is something staring can’t prevent: they’re picking up our superbugs. In Australia, one in five seagulls studied was harbouring antibiotic-resistant human bacteria. Chris Smith went to see Sam Abraham, the scientist behind the discovery…
Sam - I’m Sam Abraham, I’m a microbiologist from Murdoch University. Seagulls across Australia are carriers of bacteria that are resistant to drugs of last resort, the ones that we really need the doctors to have to save our lives. So we went across Australia to pretty much most states. We took the seagull droppings and then placed them onto agar plates which are infused with certain drugs. Then we took the bacteria out to confirm that they are absolutely a resistant bacteria.
Chris - Are they resistant in the same way that those sorts of bacteria that cause infections in humans are resistant?
Sam - Absolutely, they are identical. So if you have an infection with this bacteria from these gulls you cannot treat it with the drugs available.
Chris - Where did the gulls get it then?
Sam - It's a very interesting question. In Australia we have a lot of gulls all around in beaches, parks, everywhere. They are typically marine feeders, but they've also picked up a habit of foraging on food waste. So if you come to Australia you will get your chips attacked by our gulls.
Chris - My Sat Nav counselled me to do the windows up and don't let the seagulls steal my chips. And you think that's how they catch, how they get these bugs?
Sam - That's one of the ways they interact with us, but they interact with human waste from landfill. They also hang around in our sewage and there is a lot of contact with drug resistant bacteria, for example bread in hospitals or nursing homes, where there's a lot of antibiotics used. And if the gulls are foraging for food in that area, they get exposed to it.
Chris - Would gulls normally have E. coli living in their intestines?
Sam - Normally we wouldn't expect these bacteria to be part of gull gut. These are human pathogens. So it is actually not the gull bacterium picking up the resistance, it's actually resistant bacteria from humans going into the gulls. There are no genetic differences between the bacteria we got out of the gulls and the bacteria causing disease in humans.
Chris - Do you think it's just here in Australia? Something inside me says absolutely not because gulls are everywhere and human practises about how we handle our rubbish, our waste and our sewage, they're going on everywhere as well.
Sam - Absolutely. If you have similar foraging habits, similar waste treatment, and the birds had the same behaviour, it will be a global phenomenon and it’s just that in Australia we did a very comprehensive study to prove that this is there, and I'm sure it'll be the same in the UK or in New Zealand or even the US.
Chris - And just gulls? Are you going to extend this to other birds, because there are lots of other foragers, crows, the crow family, magpies for example, they're really good at picking through rubbish and they hang around in the same sorts of places that gulls do. Do you think that the same phenomenon may well emerge there?
Sam - That is an area that we are studying. So gulls are what we call “colonial breeders.” They live in large colonies with a limit of predation. Any birds that are scavengers and have similar lifestyle to gulls we expect to see that. So we are looking at ibises, ducks, we have a study running in penguins and pigeons as well.
Chris - So would you anticipate that, because they are these colonial breeders, they’re hanging around these big groups, that as soon as one picks this up, is going to poop it out into the environment where the others are all hanging around. So even if only one picks it up initially, it can quite quickly establish in the rest of the colony? Is that why you've got this dramatic prevalence?
Sam - That's the hypothesis that we're working on at the moment, because the colonial breeding habitat also provides for the accelerated dissemination.
Chris - Closing the loop, it's gone from a human into a gull, and quite possibly other bird species as well. Evidence that it could come back, or feed back into and cause human infection again?
Sam - It goes back to your Sat Nav that’s giving you information about what to do with gulls. So it's to do with… if we interact with the same areas where the gulls interact and live, beaches, parks. So for example, my child going and playing in the play equipment that had fresh seagull dropping, and if he goes and plays and puts his hand on some fresh dropping, and accidentally put his hand in the mouth, he's going to immediately get inoculated. That is where our public health concern for this finding lies actually.