WHO Updates List of Most Threatening Drug-Resistant Bacteria

The World Health Organization (WHO) has updated its Bacterial Priority Pathogens List (BPPL) as of May 17, 2024, identifying the top 15 families of antibiotic-resistant bacteria that pose significant threats to human health. These pathogens are categorized into critical, high, and medium priority groups to guide the development of new treatments and combat the growing issue of antimicrobial resistance (AMR).

AMR occurs when bacteria, viruses, fungi, and parasites evolve to resist the effects of medications, leading to prolonged illnesses and increased risk of spread and mortality. This resistance is primarily driven by the misuse and overuse of antimicrobials. The revised BPPL takes into account recent findings and professional opinions with the goal of guiding research and development (R&D) activities for new antibiotics and promoting international collaboration to foster innovation.

Dr. Yukiko Nakatani, WHO’s Assistant Director-General for Antimicrobial Resistance ad interim, highlighted the importance of the updated list: “By mapping the global burden of drug-resistant bacteria and assessing their impact on public health, this list is key to guiding investment and grappling with the antibiotics pipeline and access crisis. Since the first Bacterial Priority Pathogens List was released in 2017, the threat of antimicrobial resistance has intensified, eroding the efficacy of numerous antibiotics and putting many of the gains of modern medicine at risk.”

The critical priority pathogens include gram-negative bacteria resistant to last-resort antibiotics and Mycobacterium tuberculosis resistant to rifampicin. These pathogens are particularly concerning due to their high burden, ability to resist treatment, and tendency to spread resistance genes to other bacteria. Gram-negative bacteria have inherent mechanisms to develop resistance to treatments and can transfer genetic material to other bacteria, which enables them to become drug-resistant as well.

High priority pathogens, such as Salmonella and Shigella, pose severe challenges, especially in low- and middle-income countries. Other high priority pathogens include Pseudomonas aeruginosa and Staphylococcus aureus, which are major concerns in healthcare settings. These bacteria are notorious for causing persistent infections and being resistant to multiple antibiotics, necessitating targeted research and public health interventions.

The list also includes medium priority pathogens like Group A and B Streptococci, Streptococcus pneumoniae, and Haemophilus influenzae, all of which present significant health burdens, especially among vulnerable populations such as children and the elderly in resource-limited settings.

Dr. Jérôme Salomon, WHO's Assistant Director-General for Universal Health Coverage, Communicable and Noncommunicable Diseases, underscored the urgency of tackling AMR: “Antimicrobial resistance jeopardizes our ability to effectively treat high burden infections, such as tuberculosis, leading to severe illness and increased mortality rates.”

The BPPL 2024 stresses the necessity for a comprehensive public health strategy to address AMR. This includes ensuring universal access to quality, affordable measures for prevention, diagnosis, and appropriate treatment of infections, as outlined in WHO’s people-centred approach and core package of AMR interventions.

Addressing these needs is crucial for mitigating the impact of AMR on public health and the global economy.