43 research outputs found
Genetic Background of Antimicrobial Resistance in Multiantimicrobial-Resistant Escherichia Coli Isolates From Feces Of Healthy Broiler Chickens In Tunisia
Multiantimicrobial-resistant Escherichia coli isolates are a global human health problem causing increasing morbidity and mortality. Genes encoding antimicrobial resistance are mainly harbored on mobile genetic elements (MGEs) such as transposons and plasmids as well as integrons, which enhance their rapid spread. The aim of this study was to characterize 83 multiantimicrobial-resistant E. coli isolates recovered from healthy broiler chickens. Among 78 tetracycline-resistant isolates, the tetA, tetB, and tetC genes were detected in 59 (75.6%), 14 (17.9%), and one (1.2%) isolates, respectively. The sul1, sul2, and sul3 genes were detected 31 (46.2%), 16 (23.8%), and 6 (8.9%) isolates, respectively, among 67 sulfonamide-resistant isolates. The PCR-based replicon typing method showed plasmids in 29 isolates, IncFIB (19), IncI1-Iγ (17), IncF (14), IncK (14), IncFIC (10), IncP (8), IncY (3), IncHI2 (1), and IncX (1). The class 1 and 2 integrons were detected in 57 and 2 isolates, respectively; one isolate harbored both integrons. Seven and one gene cassette arrays were identified in class 1 and class 2 integrons, respectively. Our findings show that multiantimicrobial-resistant E. coli isolates from chickens serve as reservoirs of highly diverse and abundant tet and sul genes and plasmid replicons. Such isolates and MGEs pose a potential health threat to the public and animal farming
Insights in the Stock Mixing Dynamics of Atlantic Bluefin Tuna in the North Atlantic
Effective fisheries management requires accurate stock identification, which can be challenging in
mixed stock fisheries such as the Atlantic bluefin tuna (Thunnus thynnus). This species is currently managed
considering two stocks known to spawn in the Mediterranean Sea and Gulf of Mexico, respectively. However,
recent studies have shown that individuals from both spawning components can interbreed at a recently
discovered spawning ground, located in the Slope Sea. A better understanding of the mixing patterns, as
well as the proportion in which both stocks interbreed in the Slope Sea are valuable for a reliable Atlantic
bluefin tuna stock assessment. With this aim, we assigned genetic origin of 2000 individuals captured at
feeding aggregates across the North Atlantic using a 96 SNP panel and analyzed the genetic profile of
500 individuals including 200 potential Slope Sea spawners (i.e., spawning capable individuals captured in
this area at the spawning season), using a 8000 SNP array. We confirmed that stock mixing occurs across
different feeding aggregates in the North Atlantic, being stronger in the Northwest Atlantic, where the
Mediterranean component was a majority at some locations within and near the Slope Sea spawning ground.
The analysis of Slope Sea spawner candidate individuals showed nearly equal representation from both
Mediterranean and Gulf of Mexico genetic origin individuals, suggesting similar contribution to the Slope
Sea origin offspring. Our findings constitute an important progress towards the understanding of the Atlantic
bluefin tuna stock mixing dynamics and the relevance of the recently discovered Slope Sea spawning ground
for the conservation of the species.En prens
The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance
INTRODUCTION
Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic.
RATIONALE
We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs).
RESULTS
Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants.
CONCLUSION
Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century
Comprendre Le Comportement Alimentaire Dans Les Systemes Alimentaires Territorialises : Vers Une Approche Holistique
<p><strong>Résumé</strong></p><p>Cet article met en lumière l'importance d'adopter une approche holistique dans l'analyse du comportement alimentaire au sein des systèmes alimentaires territorialisés. Ces systèmes, axés sur la proximité géographique, jouent un rôle croissant dans la promotion de l'alimentation locale et durable. L'étude explore les divers facteurs qui influent sur les choix alimentaires, allant des traditions culturelles aux considérations environnementales. Elle met également en avant l'interaction complexe entre les acteurs du système, tels que les producteurs, les distributeurs et les consommateurs, et souligne l'importance des politiques alimentaires adaptées. En adoptant une perspective holistique, l'article propose une vision complète des enjeux liés au comportement alimentaire dans ces systèmes, offrant ainsi des perspectives innovantes pour une alimentation plus équilibrée et respectueuse de l'environnement au niveau local.</p><p><strong>Mots-clés : </strong>Comportement alimentaire ; système alimentaire ; système alimentaire territorialisé ; Approche holistique.</p><p> </p><p><strong>Abstract</strong></p><p>This article highlights the importance of adopting a holistic approach In the analysis of food behavior within territorialized food systems. These systems, focused on geographical proximity, play a growing role in promoting local and sustainable food. The study explores the various factors that influence food choices, ranging from cultural traditions to environmental considerations. It also highlights the complex interaction between actors in the system, such as producers, distributors and consumers, and underlines the importance of adapted food policies. By adopting a holistic perspective, the article offers a comprehensive vision of the issues related to food behavior in these systems, thus offering innovative perspectives for a more balanced and environmentally-friendly diet at the local level.</p><p><strong>Keywords: </strong>Eating behavior; food system; localized food system; holistic approach.</p><p> </p>
Comprendre Le Comportement Alimentaire Dans Les Systemes Alimentaires Territorialises : Vers Une Approche Holistique
<p><strong>Résumé</strong></p><p>Cet article met en lumière l'importance d'adopter une approche holistique dans l'analyse du comportement alimentaire au sein des systèmes alimentaires territorialisés. Ces systèmes, axés sur la proximité géographique, jouent un rôle croissant dans la promotion de l'alimentation locale et durable. L'étude explore les divers facteurs qui influent sur les choix alimentaires, allant des traditions culturelles aux considérations environnementales. Elle met également en avant l'interaction complexe entre les acteurs du système, tels que les producteurs, les distributeurs et les consommateurs, et souligne l'importance des politiques alimentaires adaptées. En adoptant une perspective holistique, l'article propose une vision complète des enjeux liés au comportement alimentaire dans ces systèmes, offrant ainsi des perspectives innovantes pour une alimentation plus équilibrée et respectueuse de l'environnement au niveau local.</p><p><strong>Mots-clés : </strong>Comportement alimentaire ; système alimentaire ; système alimentaire territorialisé ; Approche holistique.</p><p> </p><p><strong>Abstract</strong></p><p>This article highlights the importance of adopting a holistic approach In the analysis of food behavior within territorialized food systems. These systems, focused on geographical proximity, play a growing role in promoting local and sustainable food. The study explores the various factors that influence food choices, ranging from cultural traditions to environmental considerations. It also highlights the complex interaction between actors in the system, such as producers, distributors and consumers, and underlines the importance of adapted food policies. By adopting a holistic perspective, the article offers a comprehensive vision of the issues related to food behavior in these systems, thus offering innovative perspectives for a more balanced and environmentally-friendly diet at the local level.</p><p><strong>Keywords: </strong>Eating behavior; food system; localized food system; holistic approach.</p><p> </p>
An Updated Combined Biomass index of abundance for North Atlantic Swordfish Stock 1963-2012
En prensa
Key factor affecting the basicity of mesoporous silicas MCM-41: effect of surfactant extraction time and Si/Al ratio
International audienc
Insights in the Stock Mixing Dynamics of Atlantic Bluefin Tuna in the North Atlantic
Effective fisheries management requires accurate stock identification, which can be challenging in
mixed stock fisheries such as the Atlantic bluefin tuna (Thunnus thynnus). This species is currently managed
considering two stocks known to spawn in the Mediterranean Sea and Gulf of Mexico, respectively. However,
recent studies have shown that individuals from both spawning components can interbreed at a recently
discovered spawning ground, located in the Slope Sea. A better understanding of the mixing patterns, as
well as the proportion in which both stocks interbreed in the Slope Sea are valuable for a reliable Atlantic
bluefin tuna stock assessment. With this aim, we assigned genetic origin of 2000 individuals captured at
feeding aggregates across the North Atlantic using a 96 SNP panel and analyzed the genetic profile of
500 individuals including 200 potential Slope Sea spawners (i.e., spawning capable individuals captured in
this area at the spawning season), using a 8000 SNP array. We confirmed that stock mixing occurs across
different feeding aggregates in the North Atlantic, being stronger in the Northwest Atlantic, where the
Mediterranean component was a majority at some locations within and near the Slope Sea spawning ground.
The analysis of Slope Sea spawner candidate individuals showed nearly equal representation from both
Mediterranean and Gulf of Mexico genetic origin individuals, suggesting similar contribution to the Slope
Sea origin offspring. Our findings constitute an important progress towards the understanding of the Atlantic
bluefin tuna stock mixing dynamics and the relevance of the recently discovered Slope Sea spawning ground
for the conservation of the species.S