A study published in Current Biology has found that wild birds such as ducks and crows living close to humans, for example in cities, are likely to carry bacteria with antimicrobial resistance (AMR). 

The research was led by scientists at Ineos Oxford Institute for antimicrobial research at Oxford University. They analysed 700 samples of bacteria taken from the guts of 30 species of wild birds across 8 countries, focusing on Campylobactor jejuni, a common diarrhoea-causing zoonotic bacteria found in birds’ gut microbiomes. Using genomic analysis and modelling, the team found that wild birds living close to humans, had a wider range of bacterial strains, and up to three times more AMR genes than birds living in more isolated environments such as mountains. This included genes associated with resistance against many commonly used human antibiotics.

LSHTM experts on AMR/from the AMR Centre who were not involved in the research have commented on the study and its potential implications. 

Brendan Wren, Professor of Microbial Pathogenesis at the London School of Hygiene & Tropical Medicine, said: 

“Most of us live in urban environments and we must consider our interactions with nature very closely. Birds have frequent encounters with humans and can spread their microbiome and associated gene-pool rapidly as they have few geographic boundaries. This study elegantly demonstrates an association that birds found in an urban environment are more likely to carry antibiotic resistance genes and the human gut pathogen Campylobacter jejuni. This bacterium happily exists in bird guts but doesn’t survive well in the natural atmosphere, yet counterintuitively is the leading cause of bacterial food poisoning worldwide. Clearly, urban birds are important for human disease transmission and for harbouring antimicrobial resistance genes.

“In my opinion, this is an important study in an under-appreciated area.  The bioinformatics approaches and analyses are solid and use more than one line of evidence.  Ideally the number of samples from non-urban birds, eg in Antarctica, could be higher – but to some extent, this study confirms what we already suspected.  Governments need a better appreciation that birds are vectors of disease and spreading gene-pools.”

Ozan Gundogdu, Associate Professor in Infection Biology at the London School of Hygiene & Tropical Medicine, said: 

“This research is timely given the importance of antimicrobial resistance. With globalisation, urbanisation and the intensification of food production systems, the study of pathogen transmission between animals and humans, and the impact on antimicrobial resistance will be crucial in us implementing novel intervention and control strategies.”