The astonishing development of resistance is one of the most worrisome problems of the last 20 years. In particular, the accumulation of resistance determinants that are able to destroy different antibiotic families at the same time bringing about multi-drug resistant (MDR) or pan-drug resistant (PDR) phenotypes, is a phenomenon almost exclusively known in clinical practice, in which resistance is maintained even under a strong selective pressure. Mutations, acquisition of resistance genes by lateral gene transfer (LTG), and selection of intrinsically resistant species are at the basis of this diffused problem.
Many studies have characterized resistant bacteria, genes, mechanisms of resistance and transfer in clinical settings, as well as clarifying the role of antibiotics (both naturally produced by microorganisms and by completely synthetic processes) in driving the resistant selection, the evolution of new mechanisms and the emergence new resistant species. However, other data, until now reported in a rather sporadic way, are emerging on the possible role of animals and some specific environmental hot-spots (ground water, soil, etc) in which resistance can develop thanks to an efficient organization in clusters of genes that are then able to be selected and spread, ultimately functioning as a reservoir for further transmission to humans.
Origin of resistance genes that we now know to belong to the so-called mobilome, and their mechanism of transferability among species and in different microbiota, has to be considered a real challenge for the future evolution and antibiotic resistance in both pathogenic and opportunistic bacteria.
This Research Topic has the aim of collecting contributions from different experts in the antibiotic resistance field, covering aspects of resistance in specific microorganisms and in diverse environments.