Effect of subinhibitory concentrations of ciprofloxacin on Mycobacterium fortuitum mutation rates

S H Gillespie, S Basu, A L Dickens, D M O'Sullivan, T D McHugh

Research output: Contribution to journalArticlepeer-review

82 Citations (Scopus)

Abstract

Objectives: Fluoroquinolones have found a place in the management of mycobacterial diseases including tuberculosis. It has been previously shown that subinhibitory concentrations of quinolones increase the mutation rate in Escherichia coli and staphylococci. The purpose of this study is to extend this observation to mycobacteria and to quantify mutation rates.

Methods: The mutation rate in Mycobacterium fortuitum to ciprofloxacin, levofloxacin, moxifloxacin, rifampicin, erythromycin and gentamicin resistance was determined when grown with and without various sub-MIC concentrations of ciprofloxacin.

Results: M. fortuitum exposed to 1/2 MIC ciprofloxacin had an increase in the mutation rate of between 72- and 120-fold when selected on quinolones or other anti mycobacterial antibiotics. Smaller, but significant increases in mutation rate were seen when the organism was exposed to lower concentrations (1/4 MIC and 1/8 MIC).

Conclusions: These data show that sub-MIC concentrations of fluoroquinolone significantly increase mutation rates and these data suggest that care must be taken to ensure that bacteria are not exposed to subinhibitory concentrations when adding quinolones to a regimen used to treat mycobacterial infection.

Original languageEnglish
Pages (from-to)344-348
Number of pages5
JournalJournal of Antimicrobial Chemotherapy
Volume56
Issue number2
DOIs
Publication statusPublished - Aug 2005

Keywords

  • fluoroquinolones
  • mycobacteria
  • quinolones
  • M. fortuitum
  • RANDOMIZED CONTROLLED TRIAL
  • PULMONARY TUBERCULOSIS
  • ESCHERICHIA-COLI
  • DRUG-RESISTANCE
  • IN-VITRO
  • PSEUDOMONAS-AERUGINOSA
  • STAPHYLOCOCCUS-AUREUS
  • BACTERICIDAL ACTIVITY
  • HIGH-FREQUENCY
  • MOXIFLOXACIN

Fingerprint

Dive into the research topics of 'Effect of subinhibitory concentrations of ciprofloxacin on Mycobacterium fortuitum mutation rates'. Together they form a unique fingerprint.

Cite this