Microbial richness and air chemistry in aerosols above the PBL confirm 2,000-km long-distance transport of potential human pathogens.

The existence of viable human pathogens in bioaerosols which can cause infection or affect human health has been the subject of little research. In this study, data provided by 10 tropospheric aircraft surveys over Japan in 2014 confirm the existence of a vast diversity of microbial species up to 3,000 m height, which can be dispersed above the planetary boundary layer over distances of up to 2,000 km, thanks to strong winds from an area covered with massive cereal croplands in Northeast (NE) Asia. Microbes attached to aerosols reveal the presence of diverse bacterial and fungal taxa, including potential human pathogens, originating from sewage, pesticides, or fertilizers. Over 266 different fungal and 305 bacterial genera appeared in the 10 aircraft transects. Actinobacteria, Bacillota, Proteobacteria, and Bacteroidetes phyla dominated the bacteria composition and, for fungi, Ascomycota prevailed over Basidiomycota. Among the pathogenic species identified, human pathogens include bacteria such as Escherichia coli, Serratia marcescens, Prevotella melaninogenica, Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus saprophyticus, Cutibacterium acnes, Clostridium difficile, Clostridium botulinum, Stenotrophomonas maltophilia, Shigella sonnei, Haemophillus parainfluenzae and Acinetobacter baumannii and health-relevant fungi such as Malassezia restricta, Malassezia globosa, Candida parapsilosis and Candida zeylanoides, Sarocladium kiliense, Cladosporium halotolerans, and Cladosporium herbarum. Diversity estimates were similar at heights and surface when entrainment of air from high altitudes occurred. Natural antimicrobial-resistant bacteria (ARB) cultured from air samples were found indicating long-distance spread of ARB and microbial viability. This would represent a novel way to disperse both viable human pathogens and resistance genes among distant geographical regions.

Temporal variability of nitrogen stable isotopes in primary uptake compartments in four streams differing in human impacts.

Understanding the variability of the natural abundance in nitrogen stable isotopes (expressed as δ(15)N) of primary uptake compartments (PUCs; e.g., epilithon or macrophytes) is important due to the multiple applications of stable isotopes in freshwater research and can give insights into environmental and anthropogenic factors controlling N dynamics in streams. While previous research has shown how δ(15)N of PUCs varies with δ(15)N of dissolved inorganic N (DIN) among streams, less is known about how δ(15)N of PUCs varies over time. Here, we examined monthly variation of δ(15)N of PUCs and of DIN species (nitrate and ammonium) over a year, and compared it among streams with contrasting human impacts and PUC types. Our results showed no evidence of isotopic seasonal patterns. Temporal variability in δ(15)N-PUCs increased with human impact, being the highest in the urban stream, probably influenced by the high variability of δ(15)N-DIN. Among compartments, in-stream PUCs characterized by fast turnover rates, such as filamentous algae, showed the highest temporal variability in δ(15)N values (from -3.6 to 23.2 ‰). Our study elucidates some of the environmental and biological controls of temporal variability of δ(15)N in streams, which should be taken into account when using stable isotopes as an ecological tool.

Air monitoring by nanopore sequencing.

While the air microbiome and its diversity are essential for human health and ecosystem resilience, comprehensive air microbial diversity monitoring has remained rare, so that little is known about the air microbiome's composition, distribution, or functionality. Here we show that nanopore sequencing-based metagenomics can robustly assess the air microbiome in combination with active air sampling through liquid impingement and tailored computational analysis. We provide fast and portable laboratory and computational approaches for air microbiome profiling, which we leverage to robustly assess the taxonomic composition of the core air microbiome of a controlled greenhouse environment and of a natural outdoor environment. We show that long-read sequencing can resolve species-level annotations and specific ecosystem functions through de novo metagenomic assemblies despite the low amount of fragmented DNA used as an input for nanopore sequencing. We then apply our pipeline to assess the diversity and variability of an urban air microbiome, using Barcelona, Spain, as an example; this randomized experiment gives first insights into the presence of highly stable location-specific air microbiomes within the city's boundaries, and showcases the robust microbial assessments that can be achieved through automatable, fast, and portable nanopore sequencing technology.

Nitrogen stable isotopes in primary uptake compartments across streams differing in nutrient availability.

High variability in the natural abundance of nitrogen stable isotopes (δ(15)N) has been reported for primary uptake compartments (PUCs; e.g., epilithon, filamentous algae, bryophytes, macrophytes) in human-impacted aquatic ecosystems, but the origin of this variability is not yet well understood. We examined how δ(15)N of different PUC types relate to δ(15)N of dissolved inorganic nitrogen (DIN) species (nitrate and ammonium) and to the stream nutrient concentrations in which they grow. We selected 25 reaches located across the fluvial network of La Tordera catchment (NE Spain, 868.5 km(2)), encompassing a gradient of human pressures from headwaters to the river valley. δ(15)N-PUC variability was mostly explained by location within the fluvial network and was strongly related to the δ(15)N of DIN species, especially of ammonium. Models were stronger for PUCs growing within the stream channel and thus using streamwater as their main source of nutrients. Regression models including nutrient concentrations improved the prediction power for δ(15)N-PUCs, suggesting that nutrient concentrations and stoichiometry cannot be ignored in explaining the natural abundance of nitrogen isotopes in PUCs. These results provide insights into what controls variability in δ(15)N of PUCs within a stream network, with implications for the application of stables isotopes as an ecological tool.

Microbial contamination in grocery stores from Portugal and Spain - The neglected indoor environment to be tackled in the scope of the One Health approach.

Microbial contamination in grocery shops (GS) should be evaluated since food commodities are commonly handled by workers and customers increasing the risk of food contamination and disease transmission. The aim of this study was to evaluate the microbial contamination in Portuguese and Spanish GS with a multi-approach protocol using passive (electrostatic dust cloths and surface swabs) sampling methods. The molecular detection of Aspergillus sections, mycotoxin analysis, screening of azole resistance as well as cytotoxicity measurement were conducted to better estimate the potential health risks of exposure and to identify possible relations between the risk factors studied. Fruits/vegetables sampling location was the one identified has being the most contaminated (bacteria and fungi) area in GS from both countries. Aspergillus section Fumigati and Fusarium species were observed in samples from Portuguese groceries with reduced susceptibilities to azoles commonly used in the clinical treatment of fungal infections. Fumonisin B2 was detected in Portuguese GS possible unveiling this emergent threat concerning occupational exposure and food safety. Overall, the results obtained raise concerns regarding human health and food safety and must be surveilled applying a One Health approach.

On the interpretation of the atmospheric mechanism transporting the environmental trigger of Kawasaki Disease.

Recent advances on the environmental determinants of Kawasaki Disease have pointed to the important role of the atmospheric transport of a still unknown agent potentially triggering the disease. The hypothesis arose from an innovative methodology combining expertise in climate dynamics, the analysis of ocean and atmosphere data, the use of dispersion models and the search for biological agents in air samples. The approach offered a new perspective to reveal the identity of the potential trigger, but at the same time, it increased the level of complexity, which could potentially lead to the misinterpretation of the mechanisms. Some years after it was originally formulated, we here provide a brief clarification on the approach and limits of the methodology in order to prevent an eventual misuse of our research ideas and theory, so that further research can better focus on the knowledge gaps that still remain open.