SHORT NOTE Isolation of drug-resistant Salmonella enterica serovar enteritidis strains in gentoo penguins from Antarctica Patricio Retamal 3 • Sebastia ´n Llanos-Soto 2 • Lucila Moreno Salas 2 • Juana Lo ´pez 1 • Juliana Vianna 4 • Jorge Herna ´ndez 5 • Gonzalo Medina-Vogel 6 • Francisco Castan ˜eda 3 • Marcela Fresno 3 • Daniel Gonza ´lez-Acun ˜a 1 Received: 8 June 2016 / Revised: 19 May 2017 / Accepted: 28 June 2017 / Published online: 7 July 2017 Ó Springer-Verlag GmbH Germany 2017 Abstract Anthropogenic activity in Antarctica constitutes a continuous risk for the introduction of infectious diseases into indigenous wildlife populations. Penguin colonies living close to human settlements or inhabiting in areas considered for tourism could be facing a greater threat of infection. Fecal samples from Pygoscelis penguins (Py- goscelis spp.) were collected from different sites within Antarctic Peninsula and South Shetlands Islands in order to assess the presence of Salmonella enterica. Bacterial identification and characterization was performed applying biochemical and molecular techniques. Isolates were tested for antimicrobial resistance by the disk diffusion method, and PCR analyses were used for detection of resistance and virulence-associated genes. Four samples (1.74%) from P. papua were found to be positive to S. enterica serovar Enteritidis strains. All of them showed phenotypic antimicrobial resistance to at least three antimicrobials, and shared a similar gene profile through PCR. Results in this study urgently call for improvements in sanitary standards for waste disposal and sewage treatment in Antarctica. To our knowledge, this is the first study to report antimicrobial resistance in S. enterica isolated from Antarctic wild species. Keywords Salmonella enterica Á Antimicrobial resistance Á Antarctica Á Gentoo penguins Introduction Extreme environmental conditions and relative geographic isolation resulted in low pathogenic pressure for Antarctic wildlife during their evolutionary history, which make them especially vulnerable to introduction of infectious diseases (Grimaldi et al. 2015). Several studies have investigated the presence of pathogenic organisms in Antarctic penguins and discussed possible implications for anthropogenic activity (Iveson et al. 2009; Grimaldi et al. 2015). In fact, the growing human influence in Antarctica represents a threat for wildlife populations, as inappropriate waste disposal, tourism, and commercial ships, may con- tribute to disseminate exotic microorganisms in the Antarctic communities (Iveson et al. 2009). On the other hand, migratory birds have also been addressed as a potential source of infection for Antarctic wildlife, as they travel back and forth to different continents and islands with the risk of encountering polluted areas during their path (Vigo et al. 2011). Salmonella enterica is a frequent cause of gastrointestinal infections for both humans and animals, with the latter acting as healthy carriers or becoming ill (Vigo et al. 2011). In Antarctica and sub- Antarctic islands, different S. enterica serotypes with implications for human and wildlife health have been iso- lated from Gentoo (Pygoscelis papua) and Adelie penguins & Daniel Gonza ´lez-Acun ˜a danigonz@udec.cl 1 Facultad de Ciencias Veterinarias, Universidad de Concepcio ´n, Av. Vicente Mendez 595, Chilla ´n, Chile 2 Facultad de Ciencias Naturales y Oceanogra ´ficas, Universidad de Concepcio ´n, Chilla ´n, Chile 3 Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile 4 Facultad de Agronomı ´a e Ingenierı ´a Forestal, Pontificia Universidad Cato ´lica de Chile, Santiago, Chile 5 Section for Zoonotic Ecology and Epidemiology, Linnaeus University, Va ¨xjo ¨, Sweden 6 Facultad de Ecologı ´a y Recursos Naturales, Universidad Andre ´s Bello, Santiago, Chile 123 Polar Biol (2017) 40:2531–2536 https://doi.org/10.1007/s00300-017-2163-7