Suchergebnisse

Anthropogenic influences in the southern polar region have been rare, but lately microorganisms associated with humans have reached Antarctica, possibly from military bases, fishing boats, scientific expeditions, and/or ship-borne tourism. Studies of seawater in areas of human intervention and proximal to fresh penguin feces revealed the presence of Escherichia coli strains least resistant to antibiotics in penguins, whereas E. coli from seawater elsewhere showed resistance to one or more of the following antibiotics: ampicillin, tetracycline, streptomycin, and trim-sulfa. In seawater samples, bacteria were found carrying extended-spectrum β-lactamase (ESBL)-type CTX-M genes in which multilocus sequencing typing (MLST) showed different sequence types (STs), previously reported in humans. In the Arctic, on the contrary, people have been present for a long time, and the presence of antibiotic resistance genes (ARGs) appears to be much more wide-spread than was previously reported. Studies of E coli from Arctic birds (Bering Strait) revealed reduced susceptibility to antibiotics, but one globally spreading clone of E. coli genotype O25b-ST131, carrying genes of ESBL-type CTX-M, was identified. In the few years between sample collections in the same area, differences in resistance pattern were observed, with E. coli from birds showing resistance to a maximum of five different antibiotics. Presence of resistance-type ESBLs (TEM, SHV, and CTX-M) in E. coli and Klebsiella pneumoniae was also confirmed by specified PCR methods. MLST revealed that those bacteria carried STs that connect them to previously described strains in humans. In conclusion, bacteria previously related to humans could be found in relatively pristine environments, and presently human-associated, antibiotic-resistant bacteria have reached a high global level of distribution that they are now found even in the polar regions.

The coronavirus disease 2019 (COVID-19) pandemic is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This pathogen has spread rapidly across the world, causing high numbers of deaths and significant social and economic impacts. SARS-CoV-2 is a novel coronavirus with a suggested zoonotic origin with the potential for cross-species transmission among animals. Antarctica can be considered the only continent free of SARS-CoV-2. Therefore, concerns have been expressed regarding the potential human introduction of this virus to the continent through the activities of research or tourism to minimise the effects on human health, and the potential for virus transmission to Antarctic wildlife. We assess the reverse-zoonotic transmission risk to Antarctic wildlife by considering the available information on host susceptibility, dynamics of the infection in humans, and contact interactions between humans and Antarctic wildlife. The environmental conditions in Antarctica seem to be favourable for the virus stability. Indoor spaces such as those at research stations, research vessels or tourist cruise ships could allow for more transmission among humans and depending on their movements between different locations the virus could be spread across the continent. Among Antarctic wildlife previous in silico analyses suggested that cetaceans are at greater risk of infection whereas seals and birds appear to be at a low infection risk. However, caution needed until further research is carried out and consequently, the precautionary principle should be applied. Field researchers handling animals are identified as the human group posing the highest risk of transmission to animals while tourists and other personnel pose a significant risk only when in close proximity (< 5 m) to Antarctic fauna. We highlight measures to reduce the risk as well as identify of knowledge gaps related to this issue. ; This work is an outcome of the Working Group of Wildlife Health Monitoring of the SCAR Expert Group of Birds and Marine Mammals. AB is supported by the Spanish Research Agency project (CTM2015-64720). AG is supported by the Defence Advanced Research Projects Agency (DARPA PREEMPT Cooperative Agreement No. D18AC00031). The content of the information does not necessarily reflect the position or the policy of the US government, and no official endorsement should be inferred. AV is supported by National Science Foundation (USA) Polar program (award # 1947040). CRM is supported by Australia's Integrated Marine Observing System. IMOS is enabled by the National Collaborative Research Infrastructure Strategy (NCRIS). It is operated by a consortium of institutions as an unincorporated joint venture, with the University of Tasmania as Lead Agent. JID is supported by Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and Universidad Nacional de La Plata UNLP (N#859). VM is supported by National Science Foundation (USA) Polar program (PLR 1543459). TB is supported by CNRS, French Polar Institute Project ECOPATH (IPEV 1151), ZATA and OSU OREME. DGA is supported by INACH T-23-19 project. ; Peer reviewed