The list was drawn up in a bid to guide and promote research and development of new antibiotics as part of WHO’s efforts to address growing global resistance to antimicrobial medicines.
It highlights in particular the threat of gram-negative bacteria that are resistant to multiple antibiotics. Those bacteria have built-in abilities to find new ways to resist treatment and can pass along genetic material that allows other bacteria to become drug-resistant as well.
"This list is a new tool to ensure research and development respond 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 WHO list is divided into three categories according to the urgency of need for new antibiotics: critical, high and medium-priority.
The most 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). They can cause severe and often deadly infections such as bloodstream infections and pneumonia.
Those bacteria have become resistant to a large number of antibiotics, including carbapenems and third-generation cephalosporins — the best available antibiotics for treating multi-drug resistant bacteria.
The second and third tiers in the list — the high and medium-priority categories — contain other increasingly drug-resistant bacteria that cause more common diseases such as campylobacter and salmonella that cause food poisoning.
Infections caused by bacteria that are resistant to antimicrobials lead to about 23,000 deaths annually in the United States and 25,000 deaths in Europe.
“Antimicrobial resistance is an alarming threat putting human and animal health in danger. We have put substantial efforts to stop its rise, but this is not enough. We must be quicker, stronger and act on several fronts,” said Vytenis Andriukaitis, European Union commissioner for health and food safety.
The U.S. Centers for Disease Control and Prevention (CDC) has deemed drug-resistant campylobacter and two types of drug-resistant salmonella among the threats it considered “serious,” comparable to the EU’s high-priority category.
Non-typhoidal Salmonella, for example, causes 100,000 drug-resistant infections annually in the United States; drug-resistant campylobacter causes more than 300,000 drug-resistant infections annually and leads to an average of 120 deaths.
“It is of particular concern that some common types of salmonella in humans, such as monophasic Salmonella Typhimurium, exhibit extremely high multi-drug resistance,” said Mike Catchpole, chief scientist at ECDC.
“Prudent use of antibiotics in human and veterinary medicine is extremely important to address the challenge posed by antimicrobial resistance. We all have a responsibility to ensure that antibiotics keep working.”