title: Antibiotic-induced modifications of the stiffness of bacterial membranes.
abstract: In the latest years the importance of high resolution analysis of the microbial cell surface has been increasingly recognized. Indeed, in order to better understand bacterial physiology and achieve rapid diagnostic and treatment techniques, a thorough investigation of the surface modifications induced on bacteria by different environmental conditions or drugs is essential. Several instruments are nowadays available to observe at high resolution specific properties of microscopic samples. Among these, AFM can routinely study single cells in physiological conditions, measuring the mechanical properties of their membrane at a nanometric scale (force volume). Such analyses, coupled with high resolution investigation of their morphological properties, are increasingly used to characterize the state of single cells. In this work we exploit such technique to characterize bacterial systems. We have performed an analysis of the mechanical properties of bacteria (Escherichia coli) exposed to different conditions. Such measurements were performed on living bacteria, by changing in real-time the liquid environment: standard phosphate buffered saline, antibiotic (ampicillin) in PBS and growth medium. In particular we have focused on the determination of the membrane stiffness modifications induced by these solutions, in particular between stationary and replicating phases and what is the effect of the antibiotic on the bacterial structure.
authors: Laboratory of Physics of Living Matter, EPFL, CH-1015 Lausanne, Switzerland. giovanni.longo@epfl.ch
authors: Giovanni
authors: G
authors: Longo
authors: Laura Marques
authors: LM
authors: Rio
authors: Andrej
authors: A
authors: Trampuz
authors: Giovanni
authors: G
authors: Dietler
authors: Alain
authors: A
authors: Bizzini
authors: Sandor
authors: S
authors: Kasas
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002462:Cell Membrane / Q000187:drug effects* / Q000502:physiology; D055598:Chemical Phenomena; D003470:Culture Media / Q000737:chemistry; D004926:Escherichia coli / Q000187:drug effects* / Q000502:physiology; D018625:Microscopy, Atomic Force; D012965:Sodium Chloride / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media; D012965:Sodium Chloride