Satellite tracking of gulls and genomic characterization of faecal bacteria reveals environmentally mediated acquisition and dispersal of antimicrobial‐resistant Escherichia coli on the Kenai Peninsula, Alaska

Abstract

Gulls (Larus spp.) have frequently been reported to carry Escherichia coli exhibiting antimicrobial resistance (AMR E. coli); however, the pathways governing the acquisition and dispersal of such bacteria are not well described. We equipped 17 landfill‐foraging gulls with satellite transmitters and collected gull faecal samples longitudinally from four locations on the Kenai Peninsula, Alaska to assess: (a) gull attendance and transitions between sites, (b) spatiotemporal prevalence of faecally shed AMR E. coli, and (c) genomic relatedness of AMR E. coli isolates among sites. We also sampled Pacific salmon (Oncorhynchus spp.) harvested as part of personal‐use dipnet fisheries at two sites to assess potential contamination with AMR E. coli. Among our study sites, marked gulls most commonly occupied the lower Kenai River (61% of site locations) followed by the Soldotna landfill (11%), lower Kasilof River (5%) and upper Kenai River (<1%). Gulls primarily moved between the Soldotna landfill and the lower Kenai River (94% of transitions among sites), which were also the two locations with the highest prevalence of AMR E. coli. There was relatively high spatial and temporal variability in AMR E. coli prevalence in gull faeces and there was no evidence of contamination on salmon harvested in personal‐use fisheries. We identified E. coli sequence types and AMR genes of clinical importance, with some isolates possessing genes associated with resistance to as many as eight antibiotic classes. Our findings suggest that gulls acquire AMR E. coli at habitats with anthropogenic inputs and subsequent movements may represent pathways through which AMR is dispersed.

Genomic data reveal international lineages of critical priority Escherichia coli harbouring wide resistome in Andean condors (Vultur gryphus Linnaeus, 1758)

“…In wild birds, CTX‐M‐14‐producing E. coli has been isolated from Larus ridibundus in Sweden (Bonnedahl et al., 2010), Sylvia atricapilla in Portugal (Silva et al., 2011), Chroicocephalus brunnicephalus in Bangladesh (Hasan et al., 2014), Milvus migrans and Tyto alba in Spain (Alcalá et al., 2016), Aegypius monachus in Mongolia (Guenther et al., 2017) and Larus sp. in Alaska (Ahlstrom et al., 2019). CTX‐M‐55‐producing E. coli has been isolated from Larus argentatus in Latvia (Stedt et al., 2015), Larus sp.…”

“…CTX‐M‐55‐producing E. coli has been isolated from Larus argentatus in Latvia (Stedt et al., 2015), Larus sp. in Alaska (Ahlstrom et al., 2019) and Corvus corone in Switzerland (Zurfluh et al., 2019); and CTX‐M‐65‐producing E. coli and Salmonella Infantis have been isolated from Turdus merula in Switzerland (Zurfluh et al., 2019) and from Bubo magellanicus in Chile, respectively (Fuentes‐Castillo et al., 2019).…”

Wildlife Is Overlooked in the Epidemiology of Medically Important Antibiotic-Resistant Bacteria

“…The authors made an interesting observation that the bla OXA-48positive isolates were obtained from temporally and spatially separated samples, suggesting the resistant strain was maintained in the gull population or in an environmental source often visited by gulls. Whether the gulls obtained CPE locally from anthropogenic sources, such as the nearby landfill, or brought them via migration remained a question that the authors may answer in their ongoing research in Alaska (6,7).…”

Dynamic Space Use of Andalusian Rice Fields by Overwintering Lesser Black-Backed Gulls is Driven by Harvest-Related Flooding

“…Arti cial shponds were selected strongly by a subset of tracked gulls, whereas the natural marshes of 2018; Martín-Vélez et al 2019, 2020. Gulls are also likely to disperse genes for antimicrobial resistance into rice elds, both when feeding at land lls or when roosting in the nearby river, which is contaminated with urban wastewaters (Ahlstrom et al 2019).…”