Detection of serogroup B Neisseria meningitides belonging to ST4821 complex in Shaanxi

Objective To understand the etiology of a meningococcal disease case, the carriage of Neisseria meningitides in the patients close contacts and the molecular epidemiology of the strains isolated. Methods PCR was performed to detect N. meningitides and its serogroup in the patients serum and throat swabs were collected from the close contacts for the culture of N. meningitides and the determination of their serogroup. All the strains isolated and the patients serum were analyzed with MLST. Results The ctrA gene was positive in the patients serum and 4 throat swabs. Three strains of N. meningitides were isolated from 15 throat swabs of the close contacts; The N. meningitides detected in the patients serum and isolated from the close contacts belonged to serogroup B. The MLST serotyping indicated that the N. meningitides detected in the patient's serum belonged to ST4821 complex, the other 3 strains belonged to ST7623, ST4821 and ST5586 respectively. Conclusion A high pathogenic N. meningitides belonging to lineage ST4821 complex was detected in the healthy population in Shannxi, which had caused infection and death. It is necessary to fully understand the carriage and infection status of N. meningitides in Shaanxi.