Background: Historically, antimicrobial resistance has been rare in US invasive meningococcal disease cases.
Methods: Meningococcal isolates (n = 695) were collected through population-based surveillance, 2012-2016, and national surveillance, 2015-2016. Antimicrobial susceptibility was assessed by broth microdilution. Resistance mechanisms were characterized using whole-genome sequencing.
Results: All isolates were susceptible to 6 antibiotics (cefotaxime, ceftriaxone, meropenem, rifampin, minocycline, and azithromycin). Approximately 25% were penicillin or ampicillin intermediate; among these, 79% contained mosaic penA gene mutations. Less than 1% of isolates were penicillin, ampicillin, ciprofloxacin, or levofloxacin resistant.
Conclusions: Penicillin- and ampicillin-intermediate isolates were common, but resistance to clinically relevant antibiotics remained rare.
Keywords: Neisseria meningitidis; penA; antibiotic resistance; antimicrobial susceptibility; ciprofloxacin; invasive meningococcal disease; penicillin.
Published by Oxford University Press for the Infectious Diseases Society of America 2022.