Comparison of Extended-Spectrum β-Lactamase (ESBL) CTX-M Genotypes in Franklin Gulls from Canada and Chile.
Migratory birds have been suggested to contribute to long-distance dispersal of antimicrobial resistant bacteria, but tests of this hypothesis are lacking. In this study we determined resistance profiles and genotypes of ESBL-producing bacteria in randomly selected Escherichia coli from Franklin´s gulls (Leucophaeus pipixcan) at breeding sites in Canada and compared with similar data from the gulls' wintering grounds in Chile. Resistant E. coli phenotypes were common, most notably to ampicillin (30.1%) and cefadroxil (15.1%). Furthermore, 17.0% of the gulls in Canada carried ESBL producing bacteria, which is higher than reported from human datasets from the same country. However, compared to gulls sampled in Chile (30.1%) the prevalence of ESBL was much lower. The dominant ESBL variants in Canada were blaCTX-M-14 and blaCTX-M-15 and differed in proportions to the data from Chile. We hypothesize that the observed differences in ESBL variants are more likely linked to recent exposure to bacteria from anthropogenic sources, suggesting high local dissemination of resistant bacteria both at breeding and non-breeding times rather than a significant trans-hemispheric exchange through migrating birds.
Centre for Ecology and Evolution in Microbial Model Systems, School of Natural Sciences, Linnaeus University, SE - 391 82 Kalmar, Sweden; Department of Infectious Diseases, Kalmar County Hospital, SE-391 85 Kalmar, Sweden.
Jonas
J
Bonnedahl
Centre for Ecology and Evolution in Microbial Model Systems, School of Natural Sciences, Linnaeus University, SE - 391 82 Kalmar, Sweden.
Johan
J
Stedt
Centre for Ecology and Evolution in Microbial Model Systems, School of Natural Sciences, Linnaeus University, SE - 391 82 Kalmar, Sweden.
Jonas
J
Waldenström
Centre for Ecology and Evolution in Microbial Model Systems, School of Natural Sciences, Linnaeus University, SE - 391 82 Kalmar, Sweden.
Lovisa
L
Svensson
Department of Medical Sciences, Uppsala University, SE-751 85 Uppsala, Sweden.
Mirva
M
Drobni
Department of Medical Sciences, Uppsala University, SE-751 85 Uppsala, Sweden.
Björn
B
Olsen
D025041:Animal Migration; D000818:Animals; D002170:Canada; D046091:Charadriiformes / Q000382:microbiology*; D002677:Chile; D004199:Disease Vectors; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D029968:Escherichia coli Proteins / Q000235:genetics*; D005838:Genotype; D018440:beta-Lactam Resistance / Q000235:genetics*; D001618:beta-Lactamases / Q000235:genetics*
D029968:Escherichia coli Proteins; D001618:beta-Lactamases; C000602253:beta-lactamase CTX-M, E coli