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

Abstract

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 (blaTEM [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], blaTEM [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.

ESBL-Producing Enterobacterales at the Human–Domestic Animal–Wildlife Interface: A One Health Approach to Antimicrobial Resistance in Piauí, Northeastern Brazil

“…In Brazil, studies on the presence of ESBL in domestic animals and free-living birds are still more scarce and were mainly concentrated in the southern and southeastern regions [41][42][43][44][45][46][47][48], with only a few studies conducted in the northeast [17,49,50]. The prevalence of ESBL-producing bacteria observed in these studies is considered variable due to the lack of a pattern in the number of samples, varying, for example, from 32 to 257 samples [50,51].…”

Current knowledge of the Southern Hemisphere marine microbiome in eukaryotic hosts and the Strait of Magellan surface microbiome project

“…In a similar fashion, kelp gulls ( Larus dominicanus ) and Magellanic penguins from Brazil were assessed using qPCR to evaluate the diversity of antibiotic genes they harbor ( Ewbank et al, 2021 ). Ecological strategies (synanthropic/remote & migratory/non opportunistic/specialized feeding) might have a strong association with antibiotic gene resistance transmission, with those related to anthropocentric activities having the greatest diversity in antibiotic resistance genes.…”

“…Its antibiotic resistant gene pool was resistant against eight drugs: tetracycline, aminoglycosides, sulfonamides, chloramphenicols, macrolides, quinolones, betalactams, and polymyxins. On the contrary, in the Magellanic penguin, a migratory, non-synanthropic, specialized feeder (it preys mainly on fish and squid), antibiotic resistance gene diversity was lower, with specific resistance against two drugs, tetracycline and quinolones ( Ewbank et al, 2021 ).…”