Phenotypic and molecular characterization of serogroup C Neisseria meningitidis associated with an outbreak in Bahia, Brazil

ObjectiveTo characterize meningococcal strains isolated from five cases of meningococcal disease (MD) associated with an outbreak in Trancoso – BA, occurred in October 2009. All cases, with the exception of a 39-year-old male, attended a dance party with approximately 1000 youngsters in a rural site.Materials and methodsThe epidemiological investigation was conducted by the Epidemiological Surveillance Service of Bahia State. Meningococcal strains were characterized at Adolfo Lutz Institute, the Brazilian National Reference Laboratory for Bacterial Meningitis by conventional techniques (serotype, serosubtype and antimicrobial susceptibility test) and by molecular methods (Pulsed-field gel electrophoresis – PFGE and Multilocus Sequence Typing – MLST).ResultsThe PFGE showed 2 closely related restriction profiles, designated as PFGE types A and A1, having 92% relatedness to each other. MLST characterization showed both A and A1 clones were ST-3780, which belongs to the ST-103 complex. All isolates displayed the phenotype C:23:P1.5 and were susceptible to all antibiotics tested.ConclusionsThis is the first reported MD outbreak associated with serogroup C ST-103 complex in Brazil, as well as the party and illicit drug-use associated outbreak.

ResumenObjetivoCaracterizar las cepas de Neisseria meningitidis (Nm) aisladas de cinco pacientes con Enfermedad Meningocócica (EM) asociada a un brote epidémico en Trancoso - BA, que ocurrió en octubre del 2009, luego de una fiesta en zona rural y en la que participaron 1000 jóvenes .Todos los casos fueron secundarios al caso primario a excepción de un paciente varón de 39 años.Materiales y métodosEl Servicio de Vigilancia Epidemiológica del Estado de Bahia realizó la investigación epidemiológica y las cepas de Nm se caracterizaron en el Laboratorio Nacional de Referencia para Meningitis, Instituto Adolfo Lutz - São Paulo mediante métodos convencionales (sero - subtipificación y prueba de sensibilidad a los antimicrobianos) y métodos moleculares (electroforesis en gel de campo pulsado- PFGE y Multilocus Sequence Typing - MLST).ResultadosLa PFGE mostró dos perfiles de restricción estrechamente relacionados designados como PFGE tipos A y A1 con 92% de relación entre sí. Ambos tipos fueron clasificados como ST-3780 mediante MLST, y pertenecientes al complejo clonal ST-103. Todos los aislados mostraron el fenotipo C: 23: P1.5 y eran susceptibles a todos los antibióticos testados.ConclusionesEste es el primer brote de EM reportado asociado a cepas de Nm serogrupo C del complejo clonal ST-103 y relacionado con el consumo de drogas en Brasil.