Emergence of Neisseria meningitidis ST-3587 harbouring bla ROB-1 and exhibiting dual resistance to penicillin and ciprofloxacin, Spain, 2024

BACKGROUNDDual penicillin- and ciprofloxacin-resistant <i>Neisseria meningitidis</i> causing invasive meningococcal disease (IMD) have recently emerged in association with sequence type (ST) 3587, harbouring ROB-1 β-lactamase (<i>bla</i> _ROB-1) and a mutated DNA gyrase (<i>gyrA</i>). These strains pose a threat to current antimicrobial treatment and prophylaxis.AIMWe aimed to characterise the first dual-resistant <i>N. meningitidis</i> ST-3587 isolates harbouring <i>bla</i> _ROB-1 and a mutated <i>gyrA</i> identified in Spain.METHODSThree <i>N. meningitidis</i> isolates encoding <i>bla</i> _ROB-1 were identified in 2024. They were characterised by whole genome sequencing to determine capsular genogroups, ST and genetic antimicrobial resistance markers. Dated phylogenetic analysis was performed alongside global ST-3587 strains.RESULTSThe three <i>bla</i> _ROB-1-encoding isolates belonged to ST-3587, genogroup Y, harboured a T91I mutation in <i>gyrA</i> and showed resistance to penicillin and ciprofloxacin. These isolates were obtained from urethral, oropharyngeal and blood samples, each from a different patient. According to the dated phylogenetic analysis of ST-3587 and the presence of <i>bla</i> _ROB-1, two clades were defined: clade I and clade II. Within clade II, subclade II.I was identified, comprising isolates which, in addition to <i>bla</i> _ROB-1, carried the T91I mutation in <i>gyrA</i>. This subclade included the three Spanish isolates, which exhibited close genetic relatedness.CONCLUSIONThis study documents the emergence of <i>N. meningitidis</i> ST-3587 with dual resistance in Europe, including a documented urogenital infection by this lineage. Continued surveillance of antimicrobial resistance in <i>N. meningitidis</i>, including non-invasive cases, is crucial for timely public health responses and effective IMD prevention strategies.