Urban ants as potential mechanical vectors of pathogenic and antibiotic-resistant bacteria in a Brazilian hospital.

Urban ants may act as mechanical carriers of pathogenic microorganisms in hospitals, potentially posing a risk to public health. To support infection control strategies, we investigated the occurrence of ants associated with clinically relevant microorganisms in a public hospital in Maceió, Alagoas, Brazil. Ants were collected from 17 hospital sectors, and the most prevalent species were Tapinoma melanocephalum and Dorymyrmex brunneus. Microbiological analyses revealed bacterial isolates associated with ants in 10 hospital areas, including emergency wards. A total of 18 bacterial isolates were identified across eight genera, including clinically relevant bacteria such as Escherichia coli, Pluralibacter gergoviae, Citrobacter koseri, Acinetobacter sp. and Pseudomonas sp. Several isolates exhibited resistance to multiple antibiotics, including carbapenems. These findings highlight the potential epidemiological relevance of ants associated with pathogenic and antibiotic-resistant bacteria in hospital environments, emphasising the need for improved pest management and environmental control measures.