One-fifth of the seagulls analysed in the study carried drug-resistant bacteria.
Australian seagulls carry superbugs that could be resistant to antibiotics, scientists have found.
In a new study published in the Journal of Antimicrobial Chemotherapy, scientists at Murdoch University in Perth, Australia warned that seagulls could transfer "antimicrobial-resistant" bacteria to humans.
The team analysed 562 faecal samples from Australian silver gulls, the most common gull in the country, and found that roughly 20% of them carried drug-resistant strains of E. coli.
This is the same bacteria that can cause disease in humans including urinary tract infections, sepsis, and in some cases meningitis. The bacteria are also similar to ones that cause disease in humans in hospitals and nursing homes.
The European Centre for Disease Prevention and Control found that in 2015, 33,000 people died due to infections with antibiotic-resistant bacteria.
Antimicrobial resistance, which includes resistance to antibiotics, is "regarded as one of the greatest threats to human and animal health," the authors wrote in the study introduction.
Birds in Europe have also been found to carry drug-resistant superbugs.
A 2017 study found drug-resistant strains of E. coli in yellow-legged gulls in southern France, which the authors called "alarming enough to make it urgently necessary to determine the contamination source of the bacteria we identified". Antimicrobial-resistant Salmonella has also been reported in wild birds in Germany.
Lead researcher Dr Abraham, lecturer in Veterinary & Medical Infectious Disease at Murdoch University, told Euronews he and his fellow authors in the study were surprised by the results.
"We were very surprised to find this resistance in Australian seagulls since Australian animals generally have low carriage of drug-resistant bacteria," he wrote in an email.
The scientists said evidence showed these resistant bacteria come from human sources including wastewater treatment as well as human and livestock waste.
Seagulls are not only migratory but also feed on leftover human food and rubbish, the study said, which could explain how the bacteria spread.
The World Health Organisation said that "poor infection control, inadequate sanitary conditions and inappropriate food-handling" can help the spread of drug resistance.
Gulls also frequent human environments and there is "potential" that they could spread bacteria to humans.
"Gulls transfer the resistance by fresh droppings. When humans get in touch with seagull dropping from Parks or beaches there is a potential for the transmission to occur between gulls and humans," Dr Abraham said.
People can protect themselves by washing their hands or using hand sanitizer after coming into contact with seagulls or their faeces, the scientists added.