When the Blue Marble Health concept challenges our current understanding of One Health.

We address the issue of reconciling the hygienist and dilutionist (H&D) perspectives for a global understanding of health as envisioned in the One Health framework. Rich and poor countries share pockets of poverty on the outskirts of urban centres, known as 'infectious bubbles', which remain high-risk areas for disease emergence due to a common failure of both the H&D perspectives. People living in these IBs are exposed to infectious microbes on a daily basis due to inadequate hygiene infrastructure, while at the same time lacking a heathy nature to act as a buffer through a dilution effect.

Wastewater sequencing as a powerful tool to reveal SARS-CoV-2 variant introduction and spread in French Guiana, South America.

The origin of introduction of a new pathogen in a country, the evolutionary dynamics of an epidemic within a country, and the role of cross-border areas on pathogen dynamics remain complex to disentangle and are often poorly understood. For instance, cross-border areas represent the ideal location for the sharing of viral variants between countries, with international air travel, land travel and waterways playing an important role in the cross-border spread of infectious diseases. Unfortunately, monitoring the point of entry and the evolutionary dynamics of viruses in space and time within local populations remain challenging.

Impact of Global Warming on the Severity of Viral Diseases: A Potentially Alarming Threat to Sustainable Aquaculture Worldwide.

With an ever-increasing human population, food security remains a central issue for the coming years. The magnitude of the environmental impacts of food production has motivated the assessment of the environmental and health benefits of shifting diets, from meat to fish and seafood. One of the main concerns for the sustainable development of aquaculture is the emergence and spread of infectious animal diseases in a warming climate.

Emergence of the Fungal Rosette Agent in the World: Current Risk to Fish Biodiversity and Aquaculture.

The emergence of pathogenic fungi is a major and rapidly growing problem (7% increase) that affects human and animal health, ecosystems, food security, and the economy worldwide. The Dermocystida group in particular has emerged relatively recently and includes species that affect both humans and animals. Within this group, one species in particular, , also known as the rosette agent, represents a major risk to global aquatic biodiversity and aquaculture, and has caused severe declines in wild fish populations in Europe and large losses in salmon farms in the USA.

Human-Altered Landscapes and Climate to Predict Human Infectious Disease Hotspots.

Background: Zoonotic diseases account for more than 70% of emerging infectious diseases (EIDs). Due to their increasing incidence and impact on global health and the economy, the emergence of zoonoses is a major public health challenge. Here, we use a biogeographic approach to predict future hotspots and determine the factors influencing disease emergence.

ONTdeCIPHER: an amplicon-based nanopore sequencing pipeline for tracking pathogen variants.

Motivation: Amplicon-based nanopore sequencing is increasingly used for molecular surveillance during epidemics (e.g. ZIKA, EBOLA) or pandemics (e.

Towards unravelling the Rosette agent enigma: Spread and emergence of the co-invasive host-pathogen complex, Pseudorasbora parva-Sphaerothecum destruens.

The emergence of non-native fungal pathogens is a growing threat to global health, biodiversity, conservation biology, food security and the global economy. Moreover, a thorough understanding of the spread and emergence of pathogens among invasive and native host populations, as well as genetic analysis of the structure of co-invasive host populations, is crucial in terms of conservation biology and management strategies. Here we combined extensive catchment sampling, molecular detection tools and genomic signatures to i) assess the prevalence of the rosette agent Sphaerothecum destruens in invasive and native fish populations in contrasting french regions, and ii) characterize the genetic diversity and population structure of its co-invasive and asymptomatic carrier Pseudorasbora parva.

Spatial variations in Leishmaniasis: A biogeographic approach to mapping the distribution of species.

Cutaneous Leishmaniasis (CL) is the most prevalent form of Leishmaniasis and is widely endemic in the Americas. Several species of are responsible for CL, a severely neglected tropical disease and the treatment of CL vary according to the different species of . We proposed to map the distribution of the species reported in French Guiana (FG) using a biogeographic approach based on environmental predictors.

Native drivers of fish life history traits are lost during the invasion process.

Rapid adaptation to global change can counter vulnerability of species to population declines and extinction. Theoretically, under such circumstances both genetic variation and phenotypic plasticity can maintain population fitness, but empirical support for this is currently limited. Here, we aim to characterize the role of environmental and genetic diversity, and their prior evolutionary history (via haplogroup profiles) in shaping patterns of life history traits during biological invasion.

Aquaculture at the crossroads of global warming and antimicrobial resistance.

In many developing countries, aquaculture is key to ensuring food security for millions of people. It is thus important to measure the full implications of environmental changes on the sustainability of aquaculture. We conduct a double meta-analysis (460 articles) to explore how global warming and antimicrobial resistance (AMR) impact aquaculture.

Emerging human infectious diseases of aquatic origin: a comparative biogeographic approach using Bayesian spatial modelling.

Background: With the increase in unprecedented and unpredictable disease outbreaks due to human-driven environmental changes in recent years, we need new analytical tools to map and predict the spatial distribution of emerging infectious diseases and identify the biogeographic drivers underpinning their emergence. The aim of the study was to identify and compare the local and global biogeographic predictors such as landscape and climate that determine the spatial structure of leptospirosis and Buruli Ulcer (BU).

Methods: We obtained 232 hospital-confirmed leptospirosis (2007-2017) cases and 236 BU cases (1969-2017) in French Guiana.

Whole-Genome Sequence of Mycobacterium ulcerans CSURP7741, a French Guianan Clinical Isolate.

Combined Nanopore and Illumina whole-genome sequencing of a French Guianan (Buruli ulcer agent) clinical isolate yielded a 5.12-Mbp genome with a 65.5% GC content, 5,215 protein-coding genes, and 51 predicted RNA genes.

The rise of the rosette agent in Europe: An epidemiological enigma.

International biodiversity assessments often overlook the role of emerging infectious pathogens in the decline of freshwater fish populations despite the many examples of emerging diseases in other more visible taxa on a global scale. Whilst the introduction of the rosette agent Sphaerothecum destruens in Europe remained an epidemiological enigma, recent findings have shown that this parasite arrived in Europe with the introduction of the healthy carrier Pseudorasbora parva from China nearly 60 years ago and its emergence went unnoticed for over 45 years despite its severe impact on European fish biodiversity. Recent reports on the host and pathogen phylogeny point towards an ancient host-pathogen co-evolution with direct implications on disease risk.

Hordes of Phages in the Gut of the Tilapia Sarotherodon melanotheron.

Preliminary studies conducted on the human gastro-intestinal tract have revealed that enteric viral communities play a preponderant role in microbial homeostatis. However to date, such communities have never been investigated in the fish gut. Herein, we examined the main ecological traits of viruses in the digestive tract of a euryhaline fish, the tilapia Sarotherodon melanotheron.

Mycobacterium ulcerans infection (Buruli ulcer) in French Guiana, South America, 1969-2013: an epidemiological study.

Background: Mycobacterium ulcerans infection is the third most common mycobacterial disease in the world after tuberculosis and leprosy. To date, transmission pathways from its environmental reservoir to humans are still unknown. In South America, French Guiana has the highest reported number of M ulcerans infections across the continent.

Global and local environmental changes as drivers of Buruli ulcer emergence.

Many emerging infectious diseases are caused by generalist pathogens that infect and transmit via multiple host species with multiple dissemination routes, thus confounding the understanding of pathogen transmission pathways from wildlife reservoirs to humans. The emergence of these pathogens in human populations has frequently been associated with global changes, such as socio-economic, climate or biodiversity modifications, by allowing generalist pathogens to invade and persist in new ecological niches, infect new host species, and thus change the nature of transmission pathways. Using the case of Buruli ulcer disease, we review how land-use changes, climatic patterns and biodiversity alterations contribute to disease emergence in many parts of the world.

Size evolution in microorganisms masks trade-offs predicted by the growth rate hypothesis.

Adaptation to local resource availability depends on responses in growth rate and nutrient acquisition. The growth rate hypothesis (GRH) suggests that growing fast should impair competitive abilities for phosphorus and nitrogen due to high demand for biosynthesis. However, in microorganisms, size influences both growth and uptake rates, which may mask trade-offs and instead generate a positive relationship between these traits (size hypothesis, SH).

Human norovirus hyper-mutation revealed by ultra-deep sequencing.

Human noroviruses (NoVs) are a major cause of gastroenteritis worldwide. It is thought that, similar to other RNA viruses, high mutation rates allow NoVs to evolve fast and to undergo rapid immune escape at the population level. However, the rate and spectrum of spontaneous mutations of human NoVs have not been quantified previously.

Single-Cell Analysis of RNA Virus Infection Identifies Multiple Genetically Diverse Viral Genomes within Single Infectious Units.

Genetic diversity enables a virus to colonize novel hosts, evade immunity, and evolve drug resistance. However, viral diversity is typically assessed at the population level. Given the existence of cell-to-cell variation, it is critical to understand viral genetic structure at the single-cell level.