๐ก Researchers investigated the evolution of intestinal bacteria that are exposed to repeated disruptions by antibiotics.
๐ Bacteria can evolve to withstand a wide range of antibiotics (ABs). ABs are likely the largest known driver of compositional changes in the gut microbiome.
๐ Ecological resilience, that is the ability of intestinal microbial communities to resist perturbation and return to the pre-AB state is mainly determined by the type of AB used, as different AB classes have distinct activities against gut bacteria, ranging from strain-specific to broad-spectrum effects. Environmental factors, including diet, environmental reservoirs, and microbial community context influence recovery of the microbiota after AB perturbations.
๐ The study involved the analysis of the effects of different classes of antibiotics on the microbiome over a period of 80 days. Using metagenomic analyses, selection of putative antibiotic resistance-promoting mutations in the bacterial populations was carried out, followed by subsequently analysing the characteristics of evolved bacterial clones isolated from the communities.
๐ด Researchers in this study track how repeated antibiotic therapy leads to the selection of antibiotic-resistant commensal bacteria, which after a while increases the resilience of the microbial community.
In certain antibiotics such as the tetracyclines, they observed an induction of prophages that was triggered by treatment with certain antibiotics. The response of a defined bacterial community to AB treatment is complex, AB-dependent, and adaptation of the community to AB exposure is caused by the rapid selection of AB-resistant mutants.
Link to the article: bit.ly/3PhfJuT
Published On: /06/2023
