In Western Australia, Neisseria meningitidis serogroup W clonal complex 11 became the predominant cause of invasive meningococcal disease in 2016. We used core-genome analysis to show emergence of a penicillin-resistant clade that had the penA_253 allele. This new penicillin-resistant clade might affect treatment regimens for this disease.
Keywords: Australia; Neisseria meningitidis; Western Australia; antimicrobial resistance; bacteria; clonal complex 11; clonal expansion; core-genome analysis; meningitis/encephalitis; meningococcal disease; penicillin resistance; serogroup W.