Trend of ciprofloxacin resistance in Neisseria gonorrhoeae strains isolated in Italy and analysis of the molecular determinants

A total of 599 Neisseria gonorrhoeae strains collected in Italy in 2 periods, 2003 to 2005 and 2007 to 2008, were screened for ciprofloxacin susceptibility by Etest. Ciprofloxacin-resistant strains (49.7%) were characterized by i) serovar determination, patterns of mutation in gyrA, and parC genes (38%, randomly selected) and ii) N. gonorrhoeae multiantigen sequence typing (56% of the strains isolated from patients who declared their sexual orientation). The percentage of ciprofloxacin-resistant strains increased from 42 (2003-2005) to 58 (2007-2008); in the second period, strains with MIC value >32 mu g/mL have been observed. Mutations in gyrA and parC genes were identified in the majority of strains (88%). Ciprofloxacin-resistant isolates among men who have sex with men (MSM) increased from 24% in 2003 to 2005 to 47% in 2007 to 2008. However, sequence types exclusively found among MSM were mostly due to a single strain. This is the first study in Italy combining N. gonorrhoeae ciprofloxacin susceptibility testing with molecular analyses and comparing the results over time. (C) 2010 Elsevier Inc. All rights reserved.