title: Fluoroquinolone resistance in non-multidrug-resistant tuberculosis-a surveillance study in New South Wales, Australia, and a review of global resistance rates.
abstract: BACKGROUND
  Fluoroquinolones (FQs) are used for drug-susceptible tuberculosis (TB) in patients unable to tolerate first-line agents. Current trials are also investigating these drugs in empiric first-line TB therapy, to improve outcomes and allow for shortened treatment regimens. Widespread FQ use in the community has resulted in FQ resistance in many microorganisms, including Mycobacterium tuberculosis. Despite this, FQ drug susceptibility testing (DST) is rarely performed in non-multidrug-resistant TB (non-MDR-TB).
  
  
  METHODS
  We conducted a 1-year surveillance study of FQ resistance on all MTB isolates from New South Wales (NSW), Australia. In addition, we performed a literature review of previous studies assessing FQ resistance in non-MDR-TB to summarize the global extent of this resistance pattern.
  
  
  RESULTS
  Two (0.6%) out of 357 MTB isolates from NSW were found to be FQ-resistant. One isolate was an MDR strain (11% of all MDR-TB). The other was isoniazid-monoresistant (0.3% of all non-MDR-TB). Eleven studies from 10 countries had performed FQ resistance surveillance on non-MDR-TB. In the majority of these studies, FQ resistance was found to be low (mean 1%; 95% confidence interval 0.2-2%).
  
  
  CONCLUSIONS
  FQ resistance in non-MDR-TB is uncommon in NSW, Australia. The existing global evidence suggests that FQ resistance remains largely confined to MDR-TB strains. In the majority of TB endemic regions, however, FQ resistance in non-MDR-TB has not been assessed. Knowledge of the prevalence of FQ resistance in MTB is essential to guide the rational use of these drugs, including their feasibility as first-line agents.
authors.affiliation: Centre for Infectious Diseases and Microbiology, Westmead Hospital, Level 3 ICPMR Building, PO Box 533, Wentworthville 2145, NSW, Australia; Sydney Medical School, The University of Sydney, NSW, Australia. Electronic address: jho@gmp.usyd.edu.au.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Ho
authors.affiliation: Centre for Infectious Diseases and Microbiology, Westmead Hospital, Level 3 ICPMR Building, PO Box 533, Wentworthville 2145, NSW, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Jelfs
authors.affiliation: Centre for Infectious Diseases and Microbiology, Westmead Hospital, Level 3 ICPMR Building, PO Box 533, Wentworthville 2145, NSW, Australia; Sydney Medical School, The University of Sydney, NSW, Australia; Sydney Emerging Infectious Diseases and Biosecurity Institute, Westmead Hospital, Wentworthville, NSW, Australia.
authors.forename: Vitali
authors.initials: V
authors.lastname: Sintchenko
mesh_terms: D000995:Antitubercular Agents / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D062665:Epidemiological Monitoring; D005260:Female; D024841:Fluoroquinolones / Q000494:pharmacology*; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000302:isolation & purification; D009517:New South Wales; D011446:Prospective Studies; D014376:Tuberculosis / Q000382:microbiology*; D018088:Tuberculosis, Multidrug-Resistant / Q000382:microbiology
chemical_list: D000995:Antitubercular Agents; D024841:Fluoroquinolones
keywords: Prevalence; Second-line drug resistance; Susceptibility testing