Arthropod-borne diseases among travellers arriving in Europe from Africa, 2015 to 2019

Background: Travellers are generally considered good sentinels for infectious disease surveillance. Aim To investigate whether health data from travellers arriving from Africa to Europe could provide evidence to support surveillance systems in Africa. Methods: We examined disease occurrence and estimated risk of infection among travellers arriving from Africa to Europe from 2015 to 2019 using surveillance data of arthropod-borne disease cases collected through The European Surveillance System (TESSy) and flight passenger volumes from the International Air Transport Association. Results: Malaria was the most common arthropod-borne disease reported among travellers from Africa, with 34,235 cases. The malaria travellers’ infection rate (TIR) was 28.8 cases per 100,000 travellers, which is 36 and 144 times higher than the TIR for dengue and chikungunya, respectively. The malaria TIR was highest among travellers arriving from Central and Western Africa. There were 956 and 161 diagnosed imported cases of dengue and chikungunya, respectively. The highest TIR was among travellers arriving from Central, Eastern and Western Africa for dengue and from Central Africa for chikungunya in this period. Limited numbers of cases of Zika virus disease, West Nile virus infection, Rift Valley fever and yellow fever were reported. Conclusions: Despite some limitations, travellers’ health data can efficiently complement local surveillance data in Africa, particularly when the country or region has a sub-optimal surveillance system. The sharing of anonymised traveller health data between regions/continents should be encouraged.Peer Reviewe

Assembly and polishing of repeat-rich fungal genomes, exemplified by the chytrid Batrachochytrium salamandrivorans

<p>Amphibian declines are a threat to global biodiversity and part of Earth’s sixth mass extinction. Amphibian extinctions and extirpations are caused by a variety of factors, including the Chytridiomycosis panzootic and its causative agents: the batrachochytrids <em>Batrachochytrium salamandrivorans </em>(<em>Bsal</em>) and <em>Batrachochytrium dendrobatidis </em>(<em>Bd</em>)<em>.</em> Until recently, the genomic basis for the batrachochytrids’ evolution and their virulence was largely unknown. To investigate their virulence and evolution, high-quality genome assemblies were needed. Prior to 2022, only a highly fragmented short-read assembly of <em>Bsal</em>’s genome assembly had been generated and made available, largely owing to its repeat-richness. In 2022, a new assembly based on deep nanopore long-read sequencing provided a much-needed improvement in both contiguity and completeness. The new assembly revealed that <em>Bsal</em> has undergone a repeat-driven genome expansion and has a highly compartmentalized genome architecture. Here, the road map to assembling and polishing a highly repeat-rich chytrid fungus genome using both long and short reads is described, detailing the methodology for each step, and explaining the rationales underpinning those steps. Considerations for tailoring this methodology to other similar genome assemblies are illustrated. Additionally, we describe how a high-quality assembly can be analysed to provide insight into the genomic architecture and the underlying evolutionary processes. </p&gt

Cyanobacterial Mats in Calcite-Precipitating Serpentinite-Hosted Alkaline Springs of the Voltri Massif, Italy

(1) Background: Microbial communities in terrestrial, calcifying high-alkaline springs are not well understood. In this study, we investigate the structure and composition of microbial mats in ultrabasic (pH 10–12) serpentinite springs of the Voltri Massif (Italy). (2) Methods: Along with analysis of chemical and mineralogical parameters, environmental DNA was extracted and subjected to analysis of microbial communities based upon next-generation sequencing. (3) Results: Mineral precipitation and microbialite formation occurred, along with mat formation. Analysis of the serpentinite spring microbial community, based on Illumina sequencing of 16S rRNA amplicons, point to the relevance of alkaliphilic cyanobacteria, colonizing carbonate buildups. Cyanobacterial groups accounted for up to 45% of all retrieved sequences; 3–4 taxa were dominant, belonging to the filamentous groups of Leptolyngbyaceae, Oscillatoriales, and Pseudanabaenaceae. The cyanobacterial community found at these sites is clearly distinct from creek water sediment, highlighting their specific adaptation to these environments

Cyanobacterial Mats in Calcite-Precipitating Serpentinite-Hosted Alkaline Springs of the Voltri Massif, Italy

(1) Background: Microbial communities in terrestrial, calcifying high-alkaline springs are not well understood. In this study, we investigate the structure and composition of microbial mats in ultrabasic (pH 10–12) serpentinite springs of the Voltri Massif (Italy). (2) Methods: Along with analysis of chemical and mineralogical parameters, environmental DNA was extracted and subjected to analysis of microbial communities based upon next-generation sequencing. (3) Results: Mineral precipitation and microbialite formation occurred, along with mat formation. Analysis of the serpentinite spring microbial community, based on Illumina sequencing of 16S rRNA amplicons, point to the relevance of alkaliphilic cyanobacteria, colonizing carbonate buildups. Cyanobacterial groups accounted for up to 45% of all retrieved sequences; 3–4 taxa were dominant, belonging to the filamentous groups of Leptolyngbyaceae, Oscillatoriales, and Pseudanabaenaceae. The cyanobacterial community found at these sites is clearly distinct from creek water sediment, highlighting their specific adaptation to these environments.</jats:p