title: Nalidixic acid disk for laboratory detection of ciprofloxacin resistance in Neisseria meningitidis.
abstract: Recently the CLSI recommended a disk diffusion method and breakpoints for meningococci which include breakpoints derived for nalidixic acid which serve as surrogate markers for gyrase A mutations associated with diminished fluoroquinolone susceptibility. This study presents the application of this methodology to a panel of 57 meningococcal strains isolated in Spain that include all levels of susceptibility to ciprofloxacin. In conclusion, the most useful method to predict isolates with gyrA mutations that decrease the activity of fluoroquinolones is the use of 30-microg nalidixic acid disks.
authors.affiliation: National Centre for Microbiology, National Institute of Health Carlos III, Majadahonda (Madrid), Spain.
authors.forename: Rocío
authors.initials: R
authors.lastname: Enríquez
authors.forename: Raquel
authors.initials: R
authors.lastname: Abad
authors.forename: Celia
authors.initials: C
authors.lastname: Salcedo
authors.forename: Julio A
authors.initials: JA
authors.lastname: Vázquez
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002939:Ciprofloxacin / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial / Q000187:drug effects* / Q000235:genetics; D006801:Humans; D008589:Meningococcal Infections / Q000453:epidemiology / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D009268:Nalidixic Acid / Q000494:pharmacology*; D009345:Neisseria meningitidis / Q000187:drug effects*; D013030:Spain / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents; D009268:Nalidixic Acid; D002939:Ciprofloxacin