Comptes Rendus Biologies最新文献

In this review article, I summarize the intervention I made during the "Hommage à François Gros" held at the Institut Pasteur in Paris on the 25th of April, 2023. I discuss how the discovery of the existence of an RNA intermediate between genetic information and protein translation has changed our perspective on the role of RNA in gene regulation in these past years. I also discuss new emerging paradigms, highlighting the role of RNA in heritable information similar to the well-known DNA function.

Ticks and tick-borne diseases are on the rise throughout the world. The reasons are multifactorial but all associated with human practices, including climate change and socio-economic and eco systemic changes. In the northern hemisphere, Lyme borreliosis and its vector, the tick belonging to the Ixodes ricinus complex, are particularly studied. Changes in forestry and the expansion of certain wild ungulates since the Second World War could explain the increasing presence of this tick in our environment. As it is likely to transmit other microorganisms potentially pathogenic to humans, an integrated multidisciplinary approach to identify human practices promoting its expansion is critical to control the (re)emergence of infectious diseases. Other ticks also benefit from the same anthropised context to increase their numbers in the environment.

As an eminent scientist, fully aware of his social responsibilities, François Gros has been consulted on several occasions on how to make better use of science in the service of society. One of the first reports asked of him was by President Giscard d'Estaing on the social and industrial consequences of the rise of biology (1979). A few years later, at the request of President François Mitterrand, he chaired the National Conference on Research and Technology (1981-1982), which led to substantial changes in the way French public research was organised.

Melioidosis is an infectious, tropical and emerging disease, due to a bacterium of the hydrotelluric environment, Burkholderia pseudomallei, which is considered as a potential biological weapon because of its exceptional resistance and virulence capacities. Its worldwide spread, outside the original endemic foci of Southeast Asia and Australia, is favoured by global warming and the diabetes mellitus pandemic, which is the main predisposing factor.In humans, melioidosis is an opportunistic infection, following professional (rice farmers, soldiers) or accidental contamination, by inhalation or inoculation. B. pseudomallei is a facultative intracellular bacterium that can overcome host immune defences, induce acute, subacute, or chronic invasive infection, or remain latent for years. The acute infection is polymorphic, bacteraemic in more than 50% of cases, frequently complicated by shock, and revealed by visceral abscesses, most often pulmonary. It is fatal in 20 to 50% of cases, the prognosis depending on the delay before the establishment of effective first-line antibiotic therapy, using ceftazidime or carbapenems, and therefore on the speed of bacteriological diagnosis.B. pseudomallei is a saprophytic bacterium, resident of the rhizosphere where it has developed and accumulated capacities to overcome environmental stresses and competition with organisms living in such ecosystem. These adaptation mechanisms are also the virulence factors that make melioidosis serious, in particular the efflux pumps that are the main support for its multi-resistance to antibiotics.

This is meant to be a personal account of my relationship with François Gros who, as the director of the laboratory where I had my first team became a close and fatherly friend. Over 60 years we had permanent interactions, whether close or far away. And I wish to revive here some of our relation at the grassroots, as well as the folklore in and around his laboratory. He was not only an excellent scientist but also a Statesman of Science and beyond. Myself a minor figure in his big endeavors, this aspect of his life I just observed from below but with much empathy. All along he considered our experimental data and ideas realistic while they were rejected as iconoclastic by the many others. Being taken seriously as a researcher, I did not participate in his professional networks because I never fit the necessary profile in terms of scientific consensus. But his friendship was a major and basic element in my scientific and personal life; I hope my report hereafter does justice to his personality and immense merits.

This article is a tribute to the action of François Gros within the COPED (Committee of Developing Countries) which he created in 1997 and led until 2017. The COPED aims to reflect on the major scientific problems posed to developing countries and to try to provide them with solutions in partnership with them. Its actions have resulted in the organization of mini-forums, workshops, international symposia and reports for governments and authorities. Without being exhaustive, a number of actions carried out by François Gros or on his initiative are described in fields as diverse as health, chemistry, agronomy, energy, applied mathematics, renewable resources management and biodiversity, or education, training and the role of women in the sustainable development of African societies. The diversity of these concerns is a good illustration of the range of areas in which François Gros saw a possible impact of science in the service of development.

Although reflection is obviously crucial in molecular biology, experimentation is nonetheless the basis of most major advances. I was lucky to begin my research career at a particularly interesting time, and privileged to have spent a number of years in Francois Gros' laboratory at the Institut Pasteur. His influence, and that of his lab, were crucial in shaping my early career.

Due to the massive use of antibiotics, antimicrobial resistance (AMR) continues to spread, endangering global disease control and environmental quality. The sources of bacteria or antimicrobial resistance genes are linked to human activities: urban, hospital and industrial discharges, livestock farms). The role of sanitation systems-sewerage, wastewater treatment and sludge treatment (WWTP)-in the problem of AMR has not yet been clearly established by the scientific community. The data available to date show that they eliminate part of the bacteria, genes and antibiotics, although this is not their primary vocation. WWTPs thus play an important filtering role to limit dissemination in the environment. On the other hand, some authors warn against their potential involvement in the selection of new resistant germs, given the conditions conducive to the exchange of genetic material between microbial strains of various types and exposed to selective agents. Today, knowledge of the mechanisms involved in the selection of antibiotic resistance and the fate of bacteria and resistance genes within sanitation systems remains limited. Research is needed to better characterize the contribution of wastewater systems and the performance of wastewater, recycled water, stormwater and sludge treatment processes.