Phenotypic convergence of bacterial adaption to sub-lethal antibiotic treatment

Abstract

Microorganisms can adapt quickly to changes in their environment, leading to various phenotypes. The dynamic for phenotypic plasticity caused by environmental variations has not yet been fully investigated. In this study, we analyzed the time-series of phenotypic changes in Staphylococcus cells during adaptive process to antibiotics stresses using flow cytometry and Raman spectroscopy. The nine antibiotics with four different mode of actions were treated in bacterial cells at a sub-lethal concentration to give adaptable stress. Although the growth rate initially varied depending on the type of antibiotic, most samples reached the maximum growth comparable to the control through the short-term adaptation after 24 h. The phenotypic diversity, which showed remarkable changes depending on antibiotic treatment, converged identical to the control over time. In addition, the phenotype with cellular biomolecules converted into a bacterial cell that enhance tolerance to antibiotic stress with increases in cytochrome and lipid. Our findings demonstrated that the convergence into the phenotypes that enhance antibiotic tolerance in a short period when treated with sub-lethal concentrations, and highlight the feasibility of phenotypic approaches in the advanced antibiotic treatment.

Phenotypic shifts induced by environmental pre-stressors modify antibiotic resistance in Staphylococcus aureus

“…All bacterial species employ ubiquitous defense strategies in response to environmental stressors, resulting in phenotypic modifications ( Tan et al, 2022 ; Wee et al, 2022 ). These altered phenotypes are transiently maintained as part of adaptive or evolutionary processes ( Horton et al, 2023 ).…”