Opportunistic Gulls Infected by Antibiotic-Resistant Bacteria Show Contrasting Movement Behaviour

Area of Science:

• Ecology and Evolutionary Biology
• Microbiology and Infectious Diseases
• Animal Behavior and Movement Ecology

Background:

• The spread of antibiotic-resistant bacteria, such as Escherichia coli, is a significant public health concern.
• The impact of asymptomatic carriage of resistant bacteria on host behavior and pathogen dispersal remains poorly understood.

Purpose of the Study:

• To investigate the effects of antibiotic-resistant Escherichia coli carriage on the movement patterns and habitat use of yellow-legged gulls (Larus michahellis).
• To compare the behavior of gulls carrying resistant E. coli versus those not carrying it, focusing on potential differences in exposure risk to antibiotic resistance.

Main Methods:

• GPS devices and accelerometers were used to track and analyze the movement patterns of yellow-legged gulls.
• A total of 39 gulls were studied: 10 carrying antibiotic-resistant E. coli and 29 not carrying it.
• Habitat use was assessed in relation to the risk of exposure to antibiotic resistance.

Main Results:

• Gulls carrying antibiotic-resistant E. coli exhibited significantly lower accumulated traveled distances compared to control individuals.
• Individuals carrying resistant E. coli moved over smaller home ranges, indicating restricted spatial activity.
• These behavioral changes were observed despite the carriage being previously considered asymptomatic.

Conclusions:

• Asymptomatic carriage of antibiotic-resistant Escherichia coli can influence host movement patterns and habitat use.
• The observed reduction in movement may have implications for the dispersal dynamics of antibiotic-resistant pathogens.
• Further research is needed to elucidate the mechanisms linking bacterial carriage to behavioral modifications in hosts.