title: Effects of subinhibitory concentrations of ciprofloxacin on Staphylococcus saprophyticus adherence and virulence in urinary tract infections.
abstract: OBJECTIVE
  Staphylococcus saprophyticus is a frequent cause of both uncomplicated and complicated urinary tract infections (UTI) in young females and has recently been established as the most prominent gram-positive uropathogen. Although the effects of subinhibitory concentrations of antimicrobials on numerous other pathogenic bacteria have been studied, little is known regarding how S saprophyticus responds under such conditions.
  
  
  METHODS
  In this study, we investigated the effects of subminimum inhibitory concentrations (MIC) of ciprofloxacin (CIP) on S saprophyticus attachment to glass microscope slides, ureteral stent material, and T24 bladder cells, as well as its effects on S saprophyticus-induced proinflammatory cytokine expression in bladder cells.
  
  
  RESULTS
  Adherence to glass microscope slides, ureteral stent material, and bladder cell monolayers were all significantly increased in the presence of sub-MIC levels of CIP. While the S saprophyticus challenge of T24 bladder cell monolayers significantly upregulated both interleukin (IL)-6 and IL-8 expression, sub-MIC CIP abrogated these effects, returning their secretion to control levels.
  
  
  CONCLUSIONS
  Our results demonstrate that exposure to sub-MIC CIP increases S saprophyticus adherence to both abiotic and biotic surfaces including urinary device material and cultured bladder cells. In addition, low levels of this antimicrobial downregulate S saprophyticus-stimulated proinflammatory cytokine secretion in the bladder. These changes may make S saprophyticus more effective at colonizing the urinary tract and highlights the need for clinicians to consider the impact of subinhibitory concentrations of antimicrobials on bacteria when designing treatment strategies to manage UTI.
authors: Department of Surgery, Division of Urology, University of Western Ontario, London, Ontario, Canada.
authors: Petar
authors: P
authors: Erdeljan
authors: Kyle W
authors: KW
authors: MacDonald
authors: Lee W
authors: LW
authors: Goneau
authors: Tyler
authors: T
authors: Bevan
authors: Rupp
authors: R
authors: Carriveau
authors: Hassan
authors: H
authors: Razvi
authors: John D
authors: JD
authors: Denstedt
authors: Peter A
authors: PA
authors: Cadieux
mesh_terms: D001422:Bacterial Adhesion / Q000187:drug effects*; D002460:Cell Line; D002939:Ciprofloxacin / Q000494:pharmacology* / Q000627:therapeutic use*; D016207:Cytokines / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D057790:Staphylococcus saprophyticus / Q000187:drug effects* / Q000472:pathogenicity* / Q000648:ultrastructure; D001743:Urinary Bladder / Q000187:drug effects / Q000382:microbiology; D014552:Urinary Tract Infections / Q000188:drug therapy* / Q000382:microbiology*; D014774:Virulence / Q000187:drug effects
chemical_list: D016207:Cytokines; D018836:Inflammation Mediators; D002939:Ciprofloxacin