A recent report shows that penicillin-resistant and ciprofloxacin-resistant meningococci are now present in the United States, findings that promoted the Centers for Disease Control and Prevention (CDC) to issue a June 18 health advisory to clinicians and public health officials.

While most Neisseria meningitidis isolates in the U.S. have been susceptible to antibiotics recommended for treatment and prevention, 11 meningococcal cases reported during 2019-2020 had isolates containing a blaROB-1 β-lactamase gene associated with penicillin resistance and mutations associated with ciprofloxacin resistance, according to the report in CDC’s Morbidity and Mortality Weekly Report. An additional 22 cases from 2013–2020 contained blaROB-1 but did not have mutations associated with ciprofloxacin resistance. A majority of the cases caused by isolates containing the blaROB-1 resistance gene occurred in young children and older adults. The 33 total cases were reported from 12 different states.

CDC’s advisory recommends that providers test meningococcal isolates for susceptibility to penicillin before changing from empirical treatment with cefotaxime or ceftriaxone to penicillin or ampicillin. In states with cases of meningococcal disease caused by ciprofloxacin-resistant strains during the past 1-2 years, clinicians and public health officials are also urged to consider susceptibility testing to inform prophylaxis decisions.

A Perspective from Ben Hanisch, MD

N. meningitidis is a well-respected pathogen in pediatrics as initial clinical symptoms can be subtle and rapidly progress to fulminant disease. Classically once N. meningitidis infection is recognized, treatment and prophylaxis are straightforward with resistance being so rare the need for susceptibility testing was unclear with many laboratories not performing susceptibility testing.

In light of the identification of 33 β-lactamase producing isolates, 11 of which were also ciprofloxacin-resistant with wide geographic variability, routine susceptibility testing for meningococcal isolates is likely needed to guide treatment and prophylaxis.

The recognition of increasing resistance is additionally complicated by the rising use of molecular diagnostics to rapidly establish the diagnosis of N. meningitidis. This reinforces the ongoing need of cultures as well as molecular diagnostics. Ongoing susceptibility data will be needed to help inform clinicians in the case of positive molecular testing and negative cultures which may occur in children treated with antibiotics prior to cultures being obtained.

Ensuring that appropriate post-exposure prophylaxis for close contacts including health care providers will be an issue that needs to be addressed as delays in prophylaxis may also be harmful.

In the era of increasing antimicrobial resistance, ongoing vigilance for changing susceptibility patterns is needed.

Ben Hanisch, MD
Division of Pediatric Infectious Diseases
Director, Transplant Infectious Disease Program
Children's National Hospital
Assistant Professor of Pediatrics
The George Washington University School of Medicine
Washington, D.C.

Disclosures: Dr. Hanisch has no financial disclosures.
Dr. Hanisch is an author of a case-report under review that includes one of the 33 isolates in this publication (under peer-review).