Occurrence and Quantification of Antimicrobial Resistance Genes in the Gastrointestinal Microbiome of Two Wild Seabird Species With Contrasting Behaviors

9 Pág Centro de Investigación en Sanidad Animal (CISA)

Antimicrobial resistance genes (ARGs) are environmental pollutants and anthropization indicators. We evaluated human interference in the marine ecosystem through the ocurrence and quantification (real-time PCRs) of 21 plasmid-mediated ARGs in enema samples of 25 wild seabirds, upon admission into rehabilitation: kelp gull (Larus dominicanus, n = 14) and Magellanic penguin (Spheniscus magellanicus, n = 11). Overall, higher resistance values were observed in kelp gulls (non-migratory coastal synanthropic) in comparison with Magellanic penguins (migratory pelagic non-synanthropic). There were significant differences between species (respectively, kelp gull and Magellanic penguin): ARGs occurrence (bla TEM [p = 0.032]; tetM [p = 0.015]; tetA [p = 0.003]; and sulII [p = 0.007]), mean number of ARGs per sample (p = 0.031), ARGs mean load percentage (aadA [p = 0.045], tetA [p = 0.031], tetM [p = 0.016], bla TEM [p = 0.032], sulII [p = 0.008]), percentage of genes conferring resistance to an antimicrobial class (betalactams [p = 0.036] and sulfonamides [p = 0.033]), mean number of genes conferring resistance to one or more antimicrobial classes (p = 0.024]), percentage of multiresistant microbiomes (p = 0.032), and clustering (p = 0.006). These differences are likely due to these species' contrasting biology and ecology - key factors in the epidemiology of ARGs in seabirds. Additionally, this is the first report of mecA in seabirds in the Americas. Further studies are necessary to clarify the occurrence and diversity of ARGs in seabirds, and their role as potential sources of infection and dispersal within the One Health chain of ARGs.

This study was financed by Coordination and Improvement of Higher Level or Education Personnel (CAPES), Brazilian National Council for Scientific and Technological Development (CNPq) ([grant numbers 304999-18 and 165364/2018-1]),São Paulo Research Foundation (FAPESP) (grant numbers [2016/20956-0 and 2018/25069-7]). The samples used in this study were collected as part of the Santos Basin Beach Monitoring Project (Projeto de Monitoramento de Praias da Bacia deSantos, PMP-BS), under ABIO N◦640/2015, required by the Brazilian Institute of the Environment and Renewable Natural Resources (IBAMA) of the Brazilian Ministry of Environment for the environmental licensing process of the oil production and transport by Petrobras at the pre-salt province

Peer reviewed