The Emergence of a Ciprofloxacin-Resistant Non-Groupable Neisseria meningitidis Strain of the Clonal Complex ST-175 in the Russian Federation

Abstract

Relevance. Unencapsulated strains of meningococcus (NmNG) very rarely cause invasive meningococcal disease. A new ciprofloxacin-resistant strain NmNG ST-175 cc175, which has recently caused several cases of invasive meningococcal infection in Europe, has been discovered in the Russian Federation.Aim. To compare the new Russian strains of NmNG ST-175 with the already characterized NmNG ST-175 and to analyze the genetic markers associated with antibiotic resistance.Materials and methods. The nucleotide sequences of NmNG ST-175 strains of more than 2 million base pairs were exported from the PubMLST database. Comparison was carried out for 1605 core genome loci using the N. meningitidis cgMLST v1.0 ". Genetic relationships of 127 NmNG ST-175 strains, including 8 Russian carrier strains, were visualized using the SplitsTree software (version 4.16.2).Results. Of the eight Russian strains, six found themselves in a cluster with German and Swedish isolates that caused invasive meningococcal infection. Two more Russian strains were closest to the isolates of the cluster, including carrier isolates from England. Seven strains showed resistance to ciprofloxacin and possessed the gyrA-187 and gyrA-152 alleles, which, based on the phylogenetic analysis of the alleles, belonged to the genetic branches of Neisseria cinerea and Nm.Conclusion. Protein vaccines alone could potentially provide protection against ST-175 NmNG. It seems promising to study the antigenic characteristics of Russian Nm strains, including NmNG ST-175, to assess the potential vaccination coverage with existing protein vaccines, the possibility of their registration on the territory of the Russian Federation, as well as the development of domestic vaccines.