Genetic diversity and characteristics of gyrA gene in Neisseria spp

Abstract

Background Neisseria meningitidis bacteria characterized by clonal complex (CC4821) showed a high resistance rate to quinolones. The aim of this study was to assess whether the DNA gyrase A gene from N.meningitidis CC4821 strains collected in China featured any specific characteristics compared to other Neisseria species. Two hundred fifty two gyrase gene sequences were analyzed, among them 77 generated in this study from N.meningitidis CC4821 strains collected in China between 1978 and 2016. Results The quinolone resistance-related gene, coding for the DNA gyrase subunit A (GyrA) protein, was highly divergent within the N.meningitidis strains whereas N. gonorrhoeae and N.lactamica counterparts appeared well conserved. Only one position, 91 (83 in E.coli gyrA gene), was linked to quinolone resistance, all resistant strains featuring the substitution T91I. The E.coli position 87, which was mutated in quinolone-resistant strains, was also divergent (position 95) in some Neisseria resistant strains. Moreover, twenty eight additional putative resistance markers were identified. Finally, putative recombination events between N.meningitidis and either N.subflava, or N.lactamica or N.cinerea as well as between N.meningitidis strains were reported. Conclusions Analyzing the evolution of gyrA gene within Neisseria spp. is critical to monitor the quinolone resistance phenotype and the acquisition of new resistance markers. Such studies are necessary for the control of the meningococcal disease and the development of new drugs targeting DNA gyrase.