WHO Lists Antibiotic-Resistant 'Priority Pathogens' for R&D

Megan Brooks

February 27, 2017

The World Health Organization (WHO) today published a list of antibiotic-resistant "priority pathogens" for which new antibiotics are now urgently need, the agency says.

The WHO published the list in a bid to help guide and promote research and development (R&D) of new antibiotics. "This list is a new tool to ensure R&D responds to urgent public health needs," Marie-Paule Kieny, PhD, WHO assistant director-general for health systems and innovation, said in a statement.

The WHO list is divided into critical-, high-, and medium-priority categories to convey the level of urgency for the antibiotics needed.

The "critical" group includes multidrug-resistant bacteria that pose a particular threat in hospitals, nursing homes, and among patients whose care requires devices such as ventilators and blood catheters. They include Acinetobacter, Pseudomonas, and various Enterobacteriaceae (including Klebsiella, E coli, Serratia, and Proteus), which can cause severe and often deadly infections, such as bloodstream infections and pneumonia.

These bacteria have become resistant to a large number of antibiotics, including carbapenems and third-generation cephalosporins – the best available antibiotics for treating multidrug-resistant bacteria, the WHO notes.

The second and third tiers in the list – the high- and medium-priority categories – contain other bacteria that are increasingly resistant to existing antibiotics and that cause more common diseases, such as gonorrhea and food poisoning.

Priority: Critical
1. Acinetobacter baumannii, carbapenem-resistance
2. Pseudomonas aeruginosa, carbapenem-resistant
3. Enterobacteriaceae, carbapenem-resistant, ESBL-producing
Priority: High
4. Enterococcus faecium, vancomycin-resistant
5. Staphylococcus aureas, methicillin-resistant, vancomycin-intermediate, and resistant
6. Helicobacter pylori, clarithromycin-resistant
7. Campylobacter spp, fluoroquinolone-resistant
8. Salmonellae, fluoroquinolone-resistant
9. Neisseria gonorrhoeae, cephalosporin-resistant, fluoroquinolone-resistant
Priority: Medium
10. Streptococcus pneumoniae, penicillin-nonsusceptible
11. Haemophilus influenzae, ampicillin-resistant
12. Shigella spp, fluoroquinolone-resistant

ESBL, extended-spectrum beta-lactamase


These bacteria require "prompt action by the scientific research community to develop new antibiotics to treat them," Dr Kieny said today during a press briefing. They were chosen for inclusion by a group of international experts on the basis of the best available evidence and strict criteria, including the level of resistance to existing treatment, mortality rates, prevalence in the community, and burden on the health system, she explained.

Mycobacterium tuberculosis was not included in the list because there is already consensus that it is the most important priority for R&D for new antibiotics and it is targeted by other dedicated and well-funded programs, Dr Kieny said. Other bacteria that were not included, such as Streptococcus groups A and B and Chlamydia, have low levels of resistance to existing treatments and do not currently pose a significant public health threat.

Antibiotic Pipeline "Practically" Dry

"This report marks a major step forward in identifying which bacteria pose the greatest risk for patient care because of a lack of effective treatments," Evelina Tacconelli, MD, PhD, who chaired the report, said in a statement.

"We hope that it will drive governments and research groups working in antibiotic development to set the right research priorities that will reduce the burden of antibiotic-resistant infections globally," added Dr Tacconelli, head of the Division of Infectious Diseases at the University of Tübingen, in Germany, and executive committee member of the European Society of Clinical Microbiology and Infectious Diseases.

Dr Kieny noted that today, just when resistance to antibiotics is reaching "alarming" levels, the antibiotic pipeline is "practically dry."

"The list is intended to signal to the scientific community and the pharmaceutical industry the areas they should focus on to address urgent public health threats. The list is also meant to spur governments to put in place policies and incentives to promote basic research and advance R&D by both publicly funded agencies and the private sector investing in new antibiotics," Dr Kieny said.

WHO. Global priority list of antibiotic-resistant bacteria. Published February 27, 2017. Full text

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