Air pollution from livestock farms has been associated with respiratory morbidity among neighbouring residents. Livestock-related emissions include bacteria and antimicrobial resistance genes (ARGs) which may alter the respiratory resistome, potentially leading to more severe and difficult-to-treat infections.
We aimed to determine the potential associations between farm emissions and the oropharyngeal (OP) acquired resistome structure in 35 COPD patients and 34 controls living in a livestock dense region in the Netherlands.
OP swabs were collected and resistome profiling was performed using ResCap (an enrichment shotgun metagenomics approach). All participants had no recent use of oral antibiotics. Exposure to livestock farm emissions was defined using modelled concentrations of endotoxin, PM10 and livestock-specific microbial air pollutants (Escherichia coli (E. coli), Staphylococcus spp., tetW and mecA).
COPD patients exhibited a higher resistome alpha diversity compared to controls (Shannon diversity, p=0.047), however there were no significant compositional differences between the groups (PERMANOVA, p=0.179). Airborne E. coli exposure was associated with significant compositional differences in the OP resistome in both COPD patients and controls (PERMANOVA, p=0.031).
The COPD airway appears to provide a favourable environment for a variety of ARGs to persist. E. coli, a common bacterial livestock commensal, may directly impact the OP resistome, or its presence could be correlated with other microbes of importance originating from the farm environment.