title: Effects of sub-minimum inhibitory concentrations of ciprofloxacin on enteroaggregative Escherichia coli and the role of the surface protein dispersin.
abstract: Enteroaggregative Escherichia coli (EAEC) are bacterial pathogens that cause watery diarrhoea, which is often persistent and can be inflammatory. The antibiotic ciprofloxacin is used to treat EAEC infections, but a full understanding of the antimicrobial effects of ciprofloxacin is needed for more efficient treatment of bacterial infections. In this study, it was found that sub-minimum inhibitory concentrations (sub-MICs) of ciprofloxacin had an inhibitory effect on EAEC adhesion to glass and mammalian HEp-2 cells. It was also observed that bacterial surface properties play an important role in bacterial sensitivity to ciprofloxacin. In an EAEC mutant strain where the hydrophobic positively charged surface protein dispersin was absent, sensitivity to ciprofloxacin was reduced compared with the wild-type strain. Identified here are several antimicrobial effects of ciprofloxacin at sub-MIC concentrations indicating that bacterial surface hydrophobicity affects the response to ciprofloxacin. Investigating the effects of sub-MIC doses of antibiotics on targeted bacteria could help to further our understanding of bacterial pathogenicity and elucidate future antibiotic treatment modalities.
authors.affiliation: Biological and Nanoscale Systems Group, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6445, USA. mortensennp@ornl.gov
authors.forename: Ninell P
authors.initials: NP
authors.lastname: Mortensen
authors.forename: Jason D
authors.initials: JD
authors.lastname: Fowlkes
authors.forename: Michael
authors.initials: M
authors.lastname: Maggart
authors.forename: Mitchel J
authors.initials: MJ
authors.lastname: Doktycz
authors.forename: James P
authors.initials: JP
authors.lastname: Nataro
authors.forename: George
authors.initials: G
authors.lastname: Drusano
authors.forename: David P
authors.initials: DP
authors.lastname: Allison
mesh_terms: D018829:Adhesins, Bacterial / Q000187:drug effects; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002460:Cell Line; D002939:Ciprofloxacin / Q000494:pharmacology*; D004847:Epithelial Cells / Q000382:microbiology; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D005898:Glass; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008826:Microbial Sensitivity Tests
chemical_list: C479827:AAP protein, E coli; D018829:Adhesins, Bacterial; D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; D002939:Ciprofloxacin