Emergence of methicillin resistance predates the clinical use of antibiotics

The discovery of antibiotics more than 80 years ago has led to considerable improvements in human and animal health. Although antibiotic resistance in environmental bacteria is ancient, resistance in human pathogens is thought to be a modern phenomenon that is driven by the clinical use of antibiotics1. Here we show that particular lineages of methicillin-resistant Staphylococcus aureus—a notorious human pathogen—appeared in European hedgehogs in the pre-antibiotic era. Subsequently, these lineages spread within the local hedgehog populations and between hedgehogs and secondary hosts, including livestock and humans. We also demonstrate that the hedgehog dermatophyte Trichophyton erinacei produces two β-lactam antibiotics that provide a natural selective environment in which methicillin-resistant S. aureus isolates have an advantage over susceptible isolates. Together, these results suggest that methicillin resistance emerged in the pre-antibiotic era as a co-evolutionary adaptation of S. aureus to the colonization of dermatophyte-infected hedgehogs. The evolution of clinically relevant antibiotic-resistance genes in wild animals and the connectivity of natural, agricultural and human ecosystems demonstrate that the use of a One Health approach is critical for our understanding and management of antibiotic resistance, which is one of the biggest threats to global health, food security and development.

The deleterious effects induced by an acute exposure of human skin to common air pollutants are prevented by extracts of Deschampsia antarctica

The homeostatic and regenerative potential of the skin is critically impaired by an increasing accumulation of air pollutants in human ecosystems. These toxic compounds are frequently implicated in pathological processes such as premature cutaneous ageing, altered pigmentation and cancer. In this scenario, innovative strategies are required to tackle the effects of severe air pollution on skin function. Here we have used a Human Skin Organotypic Culture (HSOC) model to characterize the deleterious effects of an acute topic exposure of human skin to moderately high concentrations of common ambient pollutants, including As, Cd, Cr, dioxins and tobacco smoke. All these toxic compunds inflict severe damage in the tissue, activating the AHR-mediated response to xenobiotics. We have further evaluated the potential of an aqueous leaf extract of the polyextremophile plant Deschampsia antarctica (Edafence) to protect human skin against the acute exposure to toxic pollutants. Our results indicate that pre-treatment of HSOC samples with this aqueous extract conuterbalances the deleterious effects of the exposure to toxic comunds and triggers the activation of key genes invoved in the redox system and in the pro-inflammatory/wound healing response in the skin, suggesting that this natural compound might be effectively used in vivo to protect human skin routinely in different daily conditions.

Imagining Sustainable Human Ecosystems with Power-to-x in-situ Resource Utilisation Technology

Extensive in-situ resource utilisation (ISRU) will be essential to enable long-duration stays on Luna and Mars and reduce reliance on resupply from Earth. Early development of ISRU technologies has focused on standalone capabilities for specific targets related to life support and ascent propellant. An unexplored opportunity remains for greatly expanding the scope of materials that can be supplied by ISRU, and for integrating various technology platforms into a larger system. Recent advances in power-to-X technology aimed at decarbonising the global economy have made it possible to drive key chemical processes using electricity with small-scale, modular reactor. This paper proposes a vision for an integrated system of ISRU processes based on power-to-X technology to produce oxygen, hydrogen, water, methane, polymers, metal alloys, and synthetic fertilisers, using Martian regolith, atmosphere, and ice. A ‘building block’ strategy is adopted to convert raw materials into versatile intermediaries, which can then be combined to form essential products. A wider range of raw materials are available on Mars compared to Luna, suggesting greater opportunity for ISRU deployment to compensate for the greater time and cost requirements for a Mars resupply mission.

DNA metabarcoding dietary analyses of the wood mouse Apodemus speciosus on Innoshima Island, Japan, and implications for primer choice

We used DNA metabarcoding to assess the seasonal diets of the large Japanese wood mouse, Apodemus speciosus (Muridae, Rodentia), in forest edges adjacent to citrus orchards on Innoshima Island, Japan. We used one chloroplast and three mitochondrial DNA barcoding markers to determine mouse diets. Among the various plant and invertebrate diets, A. speciosus typically consumed Chinese cork oak (Quercus variabilis) in early spring (likely acorns preserved during winter) and gypsy moths (Lymantria dispar, a forest pest) in late spring and summer. In addition, we found that A. speciosus also preyed on orchard pests, including the gutta stink bug and other potentially harmful invertebrates. The season during which A. speciosus preyed on stink bugs corresponded with the harvest of orchard products. This study revealed several of the ecological roles of A. speciosus within the boundary zone between forest and human ecosystems. Furthermore, based on the performance of various mitochondrial markers in dietary profiling of invertebrate food items, we recommend the multi-locus DNA metabarcoding method to comprehensively assess the diet of A. speciosus.

Characterizing enterotypes in human metagenomics: a viral perspective

The diversity and high genomic mutation rates of viral species hinder our understanding of viruses and their contributions to human health. Here we investigated the human fecal virome using previously published sequencing data of 2,690 metagenomes from seven countries. We found that the virome was dominated by double-stranded DNA viruses, and young children and adults showed dramatic differences in their fecal enterovirus composition. Beta diversity showed there were significantly higher distances to centroids in individuals with severe phenotypes, such as cirrhosis. In contrast, there were no significant differences in lengths to centroids or viral components between patients with mild phenotypes, such as hypertension. Enterotypes showed the same specific viruses and enrichment direction after independent determination of enterotypes in various projects. Confounding factors, such as different sequencing platforms and library construction, did not result in a batch effect to confuse enterotype assignment. The gut virome composition pattern could be described by two viral enterotypes, which supported a discrete, rather than a gradient, distribution. Compared with enterotype 2, enterotype 1 had a higher viral count and Shannon index, but a lower beta diversity, indicating more resistance to the external environments' harmful effects. Disease was usually accompanied by a viral enterotype disorder. However, a sample outside of the enterotyping mathematical space of enterotype database did not necessarily indicate sickness. Therefore, the background context must be carefully considered when using a viral enterotype as a biomarker for disease prediction. The disease, second only to the enterotype, explains significant variation in viral community composition, implying that double-stranded DNA is relevant to human health. Our results of investigating a baseline viral database highlight important insights into the virome composition of human ecosystems, and provide an alternate biomarker for early disease screening.

Assessment of meteorological drought in agricultural locations from Venezuela under future projections of climate change

Drought is a phenomenon that is difficult to detect and predict, and with devastating consequences for natural, agricultural and human ecosystems. In order to know the future effects that climate change could have on this phenomenon in eight agricultural localities of Venezuela, the changes in the magnitude and duration of meteorological drought events were evaluated, for the reference series and for future series (period 2050s), projected by NCAR-CCSM4, GISS-E2-R, NIMR-HADGEM2-AO and MPI-ESM-LR models, for RCP 2.6 and RCP 8.5 scenarios. Drought events were estimated using the Standardized Precipitation Index (SPI) for the monthly scale and keeping the shape and scale parameters of the reference period. The results reveal a high variability of drought events among stations, models and scenarios; but with a common increase of the magnitude and duration of drought events for all models, mainly under the RCP 8.5 scenario. For the NCAR-CCSM4 model, there would be the greatest increase in the analyzed characteristics, in contrast to the NIMR-HADGEM2-AO model. The localities with droughts of greater magnitude and duration would be Barinitas and Pariaguán.

Molecular epidemiology of Brucella species in mixed livestock-human ecosystems in Kenya

Brucellosis, caused by several species of the genus Brucella, is a zoonotic disease that affects humans and animal species worldwide. Information on the Brucella species circulating in different hosts in Kenya is largely unknown, thus limiting the adoption of targeted control strategies. This study was conducted in multi-host livestock populations in Kenya to detect the circulating Brucella species and assess evidence of host–pathogen associations. Serum samples were collected from 228 cattle, 162 goats, 158 sheep, 49 camels, and 257 humans from Narok and Marsabit counties in Kenya. Information on age, location and history of abortion or retained placenta were obtained for sampled livestock. Data on age, gender and location of residence were also collected for human participants. All samples were tested using genus level real-time PCR assays with primers specific for IS711 and bcsp31 targets for the detection of Brucella. All genus positive samples (positive for both targets) were further tested with a speciation assay for AlkB and BMEI1162 targets, specific for B. abortus and B. melitensis, respectively. Samples with adequate quantities aggregating to 577 were also tested with the Rose Bengal Test (RBT). A total of 199 (33.3%) livestock and 99 (38.5%) human samples tested positive for genus Brucella. Animal Brucella PCR positive status was positively predicted by RBT positive results (OR = 8.3, 95% CI 4.0–17.1). Humans aged 21–40 years had higher odds (OR = 2.8, 95% CI 1.2–6.6) of being Brucella PCR positive compared to the other age categories. The data on detection of different Brucella species indicates that B. abortus was detected more often in cattle (OR = 2.3, 95% CI 1.1–4.6) and camels (OR = 2.9, 95% CI 1.3–6.3), while B. melitensis was detected more in sheep (OR = 3.6, 95% CI 2.0–6.7) and goats (OR = 1.7, 95% CI 1.0–3.1). Both B. abortus and B. melitensis DNA were detected in humans and in multiple livestock host species, suggesting cross-transmission of these species among the different hosts. The detection of these two zoonotic Brucella species in humans further underpins the importance of One Health prevention strategies that target multiple host species, especially in the multi-host livestock populations.

Future Scenarios for Land Use in Chile: Identifying Drivers of Change and Impacts over Protected Area System

Chile is a country that depends on the extraction and export of its natural resources. This phenomenon has exacerbated different processes of transformation and disturbance of natural and human ecosystems. Land use change has become a key factor for the transformation of ecosystems, causing consequences for biodiversity conservation. In this study, current and future (2030, 2050 and 2080) land use categories were evaluated. Land use projections were analysed together with models of ecosystem distribution in Chile under different climate scenarios, to finally analyse different dynamics of land use change within the protected areas system. In all the scenarios evaluated, land use projections showed an increase in the areas of industrial forest plantations and urban areas and a decrease in natural and agricultural areas could be expected. In relation to ecosystem modeling, vegetational formations located in the center and south of the country could be expected to decrease, while vegetational formations in the north and center of the country could extend their surface area. Inside Chile’s protected area network, anthropic disturbances are currently undergoing expansion, which could have consequences for ecosystems and protected areas located in the central and central–south zones of Chile.

Emergence of Bat-Related Betacoronaviruses: Hazard and Risks

The current Coronavirus Disease 2019 (COVID-19) pandemic, with more than 111 million reported cases and 2,500,000 deaths worldwide (mortality rate currently estimated at 2.2%), is a stark reminder that coronaviruses (CoV)-induced diseases remain a major threat to humanity. COVID-19 is only the latest case of betacoronavirus (β-CoV) epidemics/pandemics. In the last 20 years, two deadly CoV epidemics, Severe Acute Respiratory Syndrome (SARS; fatality rate 9.6%) and Middle East Respiratory Syndrome (MERS; fatality rate 34.7%), plus the emergence of HCoV-HKU1 which causes the winter common cold (fatality rate 0.5%), were already a source of public health concern. Betacoronaviruses can also be a threat for livestock, as evidenced by the Swine Acute Diarrhea Syndrome (SADS) epizootic in pigs. These repeated outbreaks of β-CoV-induced diseases raise the question of the dynamic of propagation of this group of viruses in wildlife and human ecosystems. SARS-CoV, SARS-CoV-2, and HCoV-HKU1 emerged in Asia, strongly suggesting the existence of a regional hot spot for emergence. However, there might be other regional hot spots, as seen with MERS-CoV, which emerged in the Arabian Peninsula. β-CoVs responsible for human respiratory infections are closely related to bat-borne viruses. Bats are present worldwide and their level of infection with CoVs is very high on all continents. However, there is as yet no evidence of direct bat-to-human coronavirus infection. Transmission of β-CoV to humans is considered to occur accidentally through contact with susceptible intermediate animal species. This zoonotic emergence is a complex process involving not only bats, wildlife and natural ecosystems, but also many anthropogenic and societal aspects. Here, we try to understand why only few hot spots of β-CoV emergence have been identified despite worldwide bats and bat-borne β-CoV distribution. In this work, we analyze and compare the natural and anthropogenic environments associated with the emergence of β-CoV and outline conserved features likely to create favorable conditions for a new epidemic. We suggest monitoring South and East Africa as well as South America as these regions bring together many of the conditions that could make them future hot spots.