Serogroup A Neisseria meningitidis with Reduced Susceptibility to Ciprofloxacin

摘要

To the Editor: Reduced suscep-tibility to cipro. oxacin of Neisseria meningitidis has been reported with increasing frequency since 1992, mainly because of mutations in the quinolone resistance determining re-gions (QRDRs) of the gyrase and topoisomerase IV genes (1,2). Re-duced . uoroquinolone susceptibility due to gyrase A mutations in serogroup A strains has previously been reported from a 2005 outbreak in Delhi, India (1). We describe 2 clinical isolates of serogroup A N. meningitidis with re-duced cipro. oxacin susceptibility that were recognized in March 2003 and April 2006 in Israel, a country with low incidence of invasive meningo-coccal disease (<2/100,000/laborato-ry-confi rmed cases/year) in which this serogroup accounts for <2% of cases (data from the National Center for Meningococci, Tel Hashomer, Israel). The 2 isolates in question (M12/03 and M24/06; suffi xes denote year of isolation) were compared with 2 fully susceptible strains, M44/01 and M23/00 (online Appendix Table, available from www.cdc.gov/EID/content/14/10/1667-appT.htm). MICs were measured by Etest (AB Biodisk, Solna, Sweden) on Mueller-Hinton agar (Difco Laboratories, Detroit, MI, USA) supplemented with 5% sheep blood. Demographic information was obtained from the Israel Ministry of Health Department of Epidemiology. Chromosomal DNA was isolated by using the NucleoBond kit (Mach-erey-Nagel, Düren, Germany). The location of the QRDR in gyrase and topoisomerase IV genes was based upon prior studies in meningococci (online Appendix Table) and on the complete sequence of strain N. men-ingitidis Z2491 (serogroup A; Gen-Bank accession no