Long survival of Neisseria meningitidis in freeze-dried cultures maintained in potentially unsuitable conditions

Abstract

Currently, diagnosis of Neisseria meningitidis in nasopharyngeal samples can be made by culture and nucleic acid amplification techniques.1 In Cuba, molecular diagnosis of meningococcal meningitis was introduced at the National Reference Laboratory for Neisseria (NRLN), in 2010, through a PCR that amplifies a fragment of the ctrA gene using the protocol described by Taha, 2000.2 This gene codes for a capsule protein that regulates the adhesion of N. meningitidis to the host, and 16 to 28% of meningococci isolates, especially in the nasopharynx, lack this gene.2 In contrast, the sodC gene, related to the production of superoxide-dismutase of this organism, is less sensitive to antigenic variation, hence its importance for molecular diagnosis in patients and asymptomatic carriers.3 Information on the meningococcal carriage is essential for public health policy,4. Still, the high number of invasive meningococci disease (IMD) affecting Cuba during the 1980s and the absence of molecular tools prevented its accurate microbiological diagnosis in carriers.