3D computer-generated image of a group of multidrug-resistant Acinetobacter spp. Courtesy: CDC/ James Archer

The World Health Organization (WHO) today published a list of bacteria for which new antibiotics are urgently needed.

The bacteria are ranked using priority ratings of “critical,” “high” and “medium.”

Carbapenem-resistant Acinetobacter baumannii tops the critical list, followed by carbapenem-resistant Pseudomonas aeruginosa and carbapenem-resistant ESBL-producing Enterobacteriaceae.

“This list is a new tool to ensure R&D responds to urgent public health needs,” said Dr. Marie-Paule Kieny, WHO’s Assistant Director-General for Health Systems and Innovation. “Antibiotic resistance is growing, and we are fast running out of treatment options. If we leave it to market forces alone, the new antibiotics we most urgently need are not going to be developed in time.”

The critical list 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.

If we leave it to market forces alone, the new antibiotics we most urgently need are not going to be developed in time. — Dr. Marie-Paule Kieny, WHO’s Assistant Director-General for Health Systems and Innovation

The list was released as G20 health experts meet this week in Berlin. “We will discuss and bring the attention of the G20 to the fight against antimicrobial resistance,” said Hermann Gröhe, German federal health minister.”WHO’s first global priority pathogen list is an important new tool to secure and guide research and development related to new antibiotics.”

In a news release, WHO explained that tuberculosis, whose resistance to treatment has been growing, was not included in the list because it is targeted by other, dedicated programmes.

The list was developed by international experts in collaboration with the Division of Infectious Diseases at the University of Tübingen in Germany. Their criteria for selecting pathogens on the list included the severity of the infections they cause; how frequently they are resistant to existing antibiotics when they spread to the community; whether they can be prevented (e.g. through good hygiene and vaccination); how many treatment options remain; and whether new antibiotics to treat them are already in the R&D pipeline.

The full priority list is:

Priority 1: CRITICAL
Acinetobacter baumannii, carbapenem-resistant
Pseudomonas aeruginosa, carbapenem-resistant
Enterobacteriaceae, carbapenem-resistant, ESBL-producing
Priority 2: HIGH
Enterococcus faecium, vancomycin-resistant
Staphylococcus aureus, methicillin-resistant, vancomycin-intermediate and resistant
Helicobacter pylori, clarithromycin-resistant
Campylobacter spp., fluoroquinolone-resistant
Salmonellae, fluoroquinolone-resistant
Neisseria gonorrhoeae, cephalosporin-resistant, fluoroquinolone-resistant

Priority 3: MEDIUM
Streptococcus pneumoniae, penicillin-non-susceptible
Haemophilus influenzae, ampicillin-resistant
Shigella spp., fluoroquinolone-resistant~TM