Emergence of resistance to ciprofloxacin in Neisseria meningitidis in Brazil.

To prevent secondary invasive meningococcal disease (IMD) cases and outbreaks, antimicrobial prophylaxis of high-risk contacts is indicated. This study reports two ciprofloxacin-resistant Neisseria meningitidis strains in Brazil. The 3523 N. meningitidis isolates collected throughout Brazil from 2009 to 2016 were evaluated for antimicrobial resistance. Meningococcal isolates showing minimal inhibitory concentrations, MICs≥0.125µg ml-1 to ciprofloxacin, were analysed to determine the presence of mutations in the quinolone resistance-determining regions (QRDRs) of gyrA and parC genes. Two ciprofloxacin-resistant N. meningitidis isolates were found, both presenting a single mutation in the quinolone resistance-determining region of the gyrA gene. These results confirmed that ciprofloxacin is still a first-line drug for chemoprophylaxis. However, we highlight the importance of continued surveillance to monitor the trends of N. meningitidis susceptibility profiles to the antimicrobials recommended for chemoprophylaxis and IMD treatment.