title: Single-cell force spectroscopy of bacteria enabled by naturally derived proteins.
abstract: Bringing the study of bacterial adhesion down to a single-cell level is critical for understanding the molecular mechanisms involved in initial bacterial attachment. We have developed a simple and versatile method for making single-cell bacterial probes to study the adhesion of single bacterial cells by atomic force microscopy (AFM). A single-cell probe was made by picking up a bacterial cell from a glass surface using a tipless AFM cantilever coated with a commercial cell adhesive Cell-Tak. The method was applied to four different bacterial strains, and single-cell adhesion was measured on three surfaces (fresh glass, hydrophilic glass, and mica). Attachment to the cantilever was stable during the AFM force measurements that were conducted for 2 h, and viability was confirmed by Live/Dead fluorescence staining at the end of each experiment. The adhesion force and final rupture length were dependent on bacterial strains, surfaces properties, and contact time. The single-cell probe offers control of cell immobilization and thus holds advantages over the commonly used multicell probes with which random immobilization is obtained by submerging the cantilever in a bacterial suspension. The reported method provides a general platform for investigating single-cell interactions of bacteria with different surfaces and other cells by AFM force spectroscopy, thus improving our understanding of the mechanisms of bacterial attachment.
authors.affiliation: Interdisciplinary Nanoscience Center (iNANO), Faculty of Science and Technology, Aarhus University , Aarhus 8000, Denmark.
authors.forename: Guanghong
authors.initials: G
authors.lastname: Zeng
authors.forename: Torsten
authors.initials: T
authors.lastname: Müller
authors.forename: Rikke L
authors.initials: RL
authors.lastname: Meyer
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry*; D002448:Cell Adhesion; D004926:Escherichia coli / Q000166:cytology* / Q000254:growth & development; D018625:Microscopy, Atomic Force; D011551:Pseudomonas fluorescens / Q000166:cytology* / Q000254:growth & development; D059010:Single-Cell Analysis; D013210:Staphylococcus / Q000166:cytology* / Q000254:growth & development
chemical_list: D001426:Bacterial Proteins