Molecular characteristics and resistance of pathogen strains from a case of epidemic meningitis epidemic in Luzhou , Sichuan

  Objective   To reveal the etiological and molecular characteristics of a meningococcal disease case in Luzhou Sichuan province.

  Methods  Real-time polymerase chain reaction (PCR) was used to detect the specific deoxyribonucleic acid fragments of Neisseria meningitidis isolated from the patient samples, and nest PCR was performed to amplify the house-keeping genes for sequencing. The strains isolated from close contacts of the meningococcal disease case were identified by latex aggregation, pulsed field gel electrophoresis, and drug susceptibility test and sequencing analysis were conducted.

  Results  Th e strain isolated from the patient samples was identified as N. meningitidis serogroup W via real-time PCR, and three house-keeping genes were amplified by nest PCR. Two strains of N. meningitidis serogroup W isolated from the close contacts shared 100.00% homology in PFGE molecular typing. The typical strain designation was W: P1.5-3, 10-2: F1-68: ST-17462(CC4821). The resistance-associated genes analysis showed that isolates harbored the mutations in quinolones resistance related locus T91I of gyrA and in penicillin-binding protein 2 (PBP2) loci of penA-552. The isolates were resistant to penicillin minimal inhibitory concentratio (MIC) 1.00 μg/mL, levofloxacin (MIC 0.12 μg/mL) and sulfamethoxazole (MIC 1/19 μg/mL).

  Conclusion  The house-keeping genes of strain from patient samples were coincident with the isolated strains in this study. The meningococcal disease case was caused by N. meningitidis serogroup W: ST-17462 (CC4821). The N. meningitidis with new sequence type was pathogenic to humans.