title: Real-time studies of the progression of bacterial infections and immediate tissue responses in live animals.
abstract: By combining intravital multiphoton microscopy and bacterial genetics we have developed a technique enabling real-time imaging of bacterial proliferation and tissue responses in a live animal. Spatial and temporal control of the infection process was achieved by microinjecting GFP(+)-expressing uropathogenic Escherichia coli (UPEC) into tubules of exteriorized kidneys in live rats. GFP(+) was introduced in the clinical UPEC strain CFT073 as a single-copy chromosomal gene fusion. Within hours, bacterial colonization was accompanied by marked ischaemic effects, perivascular leakage, loss of tubular integrity and localized recruitment of immune cells. The pathophysiology was altered in response to an isogenic bacterial strain lacking the exotoxin haemolysin, revealing the subtle and temporal roles of bacterial virulence factors in vivo. Microdissection and RNA extraction of the injected nephron allowed molecular analysis of prokaryotic and eukaryotic gene expression. The techniques described here can be applied to study the integrated cell communication evoked by a variety of bacterial pathogens, assisting in the design of strategies to combat bacterial infections.
authors.affiliation: Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, S-171 77 Stockholm, Sweden.
authors.forename: Lisa E
authors.initials: LE
authors.lastname: Månsson
authors.forename: Keira
authors.initials: K
authors.lastname: Melican
authors.forename: Jorrit
authors.initials: J
authors.lastname: Boekel
authors.forename: Ruben M
authors.initials: RM
authors.lastname: Sandoval
authors.forename: Isabelle
authors.initials: I
authors.lastname: Hautefort
authors.forename: George A
authors.initials: GA
authors.lastname: Tanner
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Molitoris
authors.forename: Agneta
authors.initials: A
authors.lastname: Richter-Dahlfors
mesh_terms: D000818:Animals; D001424:Bacterial Infections / Q000473:pathology*; D003199:Computer Systems; D018450:Disease Progression; D004926:Escherichia coli / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000382:microbiology / Q000473:pathology; D049452:Green Fluorescent Proteins; D007091:Image Processing, Computer-Assisted; D010538:Peritonitis / Q000382:microbiology / Q000473:pathology; D051381:Rats; D014552:Urinary Tract Infections / Q000382:microbiology / Q000473:pathology
chemical_list: D049452:Green Fluorescent Proteins