Rifampin-resistant Neisseria meningitidis

To The Editor: Immediate management of meningococcal disease requires antimicrobial drug treatment of patients with β-lactams and chemo-prophylaxis of contact persons with rifampin. High-level resistance to rifampin (MIC >32 mg/L) in Neisseria meningitidis is provoked by mutations (most frequently at the residue His 552) in the rpoB gene encoding the β subunit of RNA poly-merase (1,2). Resistance may lead to chemoprophylaxis failure and must be rapidly detected (3). Concerns have been raised about the clonal spread of resistant isolates (1); however, rifampin-resistant isolates are rarely reported. We tested 6 N. meningitidis isolates corresponding to 3 pairs of linked cases of meningococcal disease. In each pair, the index case was due to a rifampin-susceptible isolate and was followed by the secondary case due to a resistant isolate in a contact person. Phenotyping and geno-typing of the isolates showed that each pair belonged to a different major serogroup (A, B, and C) and to a different genetic lineage (ST-7, ST-32, and ST-2794) (Figure). We next amplified a fragment in rpoB between codons 421 and 701 by using oligonu-cleotide rpoBF1