Greater ciprofloxacin tolerance as a possible selectable phenotype underlying the pandemic spread of the H30 subclone of Escherichia coli sequence type 131.
Minimum bactericidal concentrations (MBCs) for ciprofloxacin were significantly higher among 41 members of the H30 subclone within Escherichia coli sequence type 131 than among 48 other fluoroquinolone-resistant E. coli isolates. This MBC difference, which was not explained by ciprofloxacin MICs, gyrA, parC, and parE mutations, the presence of aac(6')-Ib-cr, or organic solvent tolerance (a surrogate for efflux pump activity), conceivably could have promoted the pandemic emergence of the H30 sequence type 131 subclone.
VA Medical Center, Minneapolis, Minnesota, USA University of Minnesota, Minneapolis-Saint Paul, Minnesota, USA johns007@umn.edu.
James R
JR
Johnson
VA Medical Center, Minneapolis, Minnesota, USA.
Stephen B
SB
Porter
VA Medical Center, Minneapolis, Minnesota, USA University of Minnesota, Minneapolis-Saint Paul, Minnesota, USA.
Paul
P
Thuras
University of Minnesota, Minneapolis-Saint Paul, Minnesota, USA.
Timothy J
TJ
Johnson
George Washington University Milken Institute School of Public Health, Washington, DC, USA.
Lance B
LB
Price
University of Washington, Seattle, Washington, USA.
Veronika
V
Tchesnokova
University of Washington, Seattle, Washington, USA.
Evgeni V
EV
Sokurenko
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002939:Ciprofloxacin / Q000494:pharmacology*; D027081:DNA Gyrase / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D004927:Escherichia coli Infections / Q000382:microbiology; D029968:Escherichia coli Proteins / Q000235:genetics; D024841:Fluoroquinolones; D008826:Microbial Sensitivity Tests; D009154:Mutation
D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; D024841:Fluoroquinolones; D002939:Ciprofloxacin; D027081:DNA Gyrase