CDC Reports 461% Spike in NDM-1 CRE Infections; European Data Show Rising Foodborne Resistance

U.S. health officials are sounding an alarm over a 461% increase in a dangerous antibiotic resistance gene, as European data reveal that foodborne pathogens remain highly resistant to critical antibiotics. The gene, New Delhi metallo-beta-lactamase (NDM), makes bacteria resistant to carbapenems, a class of last-resort antibiotics used when infections don't respond to first- and second-line treatments.

In a September report, the CDC said surveillance data from labs across the country showed that the incidence of carbapenem-resistant Enterobacterales (CRE) infections carrying NDM genes rose 461% from 2019 through 2023. A CDC bioinformatician said the rapid increase is a major concern due to the implications for treating serious CRE infections and the potential for NDM to spread outside of healthcare.

All CRE infections, dubbed "nightmare bacteria," present a challenge for physicians because they tend to target already sick hospital patients and limit treatment options. The mortality rate for CRE infections ranges from 30% to 50%, and the CDC labeled CRE an "urgent threat" in a 2019 report. NDM is one of several carbapenemase genes, alongside KPC and VIM, that CRE pathogens have acquired to evade carbapenems.

Meanwhile, a joint report from the European Food Safety Authority and the European Centre for Disease Prevention and Control found that a high proportion of Salmonella and Campylobacter isolates collected from humans and food-producing animals in 2023-24 were resistant to commonly used antibiotics, including ampicillin, tetracycline, and sulfonamides. Resistance to ciprofloxacin, a critically important antibiotic, is increasing in both pathogens from humans and poultry, to the point that fluoroquinolones can no longer be used for Campylobacter infections.

The report also noted increasing detection of carbapenemase-producing Escherichia coli in food-producing animals and meat in several countries, which warrants close attention because carbapenems are a last-resort option for severe human infections and are not authorized for use in veterinary medicine.

On a more positive note, several countries reported declining resistance to ampicillin and tetracyclines in Salmonella isolates from humans and poultry, along with decreased resistance to erythromycin, a first-line treatment for Campylobacter infections. Few isolates showed resistance to more than one critically important antibiotic at the same time. ECDC's chief scientist emphasized that protecting antimicrobial effectiveness requires coordinated action through a strong One Health approach, as antimicrobial resistance affects both humans and animals.