Objective To analyze the antibiotic susceptibility and molecular type of 72 Neisseria meningitidisstrains isolated in the northwestern area of Hubei province from 2008 to 2017.

Methods Biochemical identification and serologically grouping of the isolates were conducted, and genotyping of the isolates was performed by using fluorescent PCR. The K-B and E-test was used to test the drug-susceptibility of the isolates, Multi locus sequence typing (MLST) and pulsed field gel electrophoresis (PFGE) was performed to understand the molecular characteristics of the isolates.

Results Among the 72 N. meningitidis strains, 14 belonged to serogroup B, 10 belonged to serogroup C, 3 belonged to serogroup W, 1 belonged to serogroup E and 44 were unspecified. The 72 strains were divided into genogroup B (n=33), genogroup C (n＝10), genogroup W (n＝3), genogroup E (n＝1) and 25 isolates were unspecified. The sensitive rates of the 70 N. meningitidis strains to cotrimoxazole, nalidixic acid, ciprofloxacin, minocycline and chloramphenicol were 7.14%, 21.43%, 28.57%, and 98.57% and 98.57%, respectively. The strains were all sensitive to remaining 7 antibiotics, i.e. meropenem, imipenem, azithromycin, ceftriaxone, cefotaxime, penicillin and rifampicin. The results of MLST showed that there were 12 different sequence types (STs) in 17 strains, 12 of the strains were unclassified complexes, the other 5 strains belonged to CC4821(n＝4) and CC175 (n＝1). The PFGE showed that 55 N. meningitidis strains could be classified into 48 different PFGE types, the strains with same PFGE type had same genotype.

Conclusion N. meningitidis B strain was predominant in northwestern Hubei from 2008 to 2017. The strain was highly resistant to cotrimoxazole, nalidixic acid and ciprofloxacin. MLST results showed that CC4821 was the predominant clonal complex. PFGE results showed the polymorphism, and no predominant PFGE pattern was found.