Antibiotics and iron-limiting conditions and their effect on the production and composition of outer membrane vesicles secreted from clinical isolates of extraintestinal pathogenic E. coli.
The focus of this study was to characterize the effect of clinically relevant stress-inducing conditions on the production and composition of proinflammatory outer membrane vesicles (OMVs) produced from ST131 extraintestinal pathogenic Escherichia coli (ExPEC) clinical isolates.



A label-free method (relative normalized spectral index quantification, SINQ) was used to identify changes in the respective OMV proteomes following exposure of the ExPEC strains to antibiotics and low iron. Nanoparticle tracking analysis was used to quantify changes in abundance and size of OMVs produced by the gentamicin-resistant (GenR) and gentamicin-sensitive (GenS) ExPEC strains.



Up to a 13.1-fold increase in abundance of particles were detected when the gentamicin-sensitive strain was exposed to a range of gentamicin concentrations. In contrast, no increase was observed for the gentamicin-resistant strain. Iron-limiting conditions had minimal effect on OMV production for either strain. Marked changes in the OMV proteome were observed for both strains including increases in Hsp100/Clp proteins, ATP-dependent ClpP protease, and regulatory proteins.



These data provide information on changes in the composition of OMV particles derived from ExPEC strains generated in response to clinically relevant conditions. We show that the levels of the proinflammatory OMVs increase for gentamicin-sensitive ExPEC exposed to the antibiotic.
Public Health England, Porton, Salisbury, UK.
Kin W
KW
Chan
Public Health England, Porton, Salisbury, UK.
Clifford
C
Shone
Public Health England, Porton, Salisbury, UK.
J Richard
JR
Hesp
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism; D002473:Cell Wall / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D024881:Drug Resistance, Bacterial / Q000187:drug effects; D049071:Endopeptidase Clp / Q000378:metabolism; D004927:Escherichia coli Infections / Q000382:microbiology / Q000473:pathology; D029968:Escherichia coli Proteins / Q000378:metabolism; D000072282:Extraintestinal Pathogenic Escherichia coli / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D007501:Iron / Q000378:metabolism*; D020543:Proteome / Q000032:analysis; D053719:Tandem Mass Spectrometry
D000900:Anti-Bacterial Agents; D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; D020543:Proteome; D007501:Iron; D049071:Endopeptidase Clp
Chaperones; Gentamicin; Outer membrane vesicles; SINQ label-free quantitation; Stress response