This fourth lesson illustrated one of the ten major health threats announced by the WHO in 2019 : the spread of antibiotic resistance, which threatens the very existence of antibiotics. The lesson considered the conditions under which antibiotic resistance arises - in particular the now delirious use of antibiotics outside human and veterinary medicine -, its molecular mechanisms according to the different antibiotics involved, and the genetic basis of the highly efficient transmissibility of resistance genes, in particular the key role of integrons, transposons and plasmids ensuring the dispersal of these genes by horizontal transfer. The repertoire of potential resistance genes (resistome) in nature is enormous (around 20 000) and constantly fuels the threat. Finally, this lesson analyzed the roots of the " antibiotic breakdown ", i.e. the crisis of innovation in the discovery of new antibiotics, which has led to fears of a " antibiotic loss " scenario, and proposed alternative avenues of research and encouragement for this research. Nevertheless, it stressed that nothing can replace the bactericidal efficacy of antibiotics and their extraordinary capacity for diffusion throughout the body. In conclusion, this lesson stressed the absolute necessity of great parsimony in the use of antibiotics, and the need for a global ban on their use for non-medical and veterinary purposes (intensive livestock farming, fish farming and agriculture).
16:00 - 17:30
