Based on disease risk, antibiotic resistance and a need for development of new treatments, the World Health Organization (WHO) has published a list of 12 priority pathogens that pose the greatest threat to human health.

The most critical pathogens and resistance trends involve multi-drug resistance in pathogens that primarily affect hospital patients, and drugs used exclusively in those settings. The three pathogens listed as “critical” priorities in the list have developed resistance to carbapenems, a group of broad-spectrum beta lactam antibiotics used to treat multi-drug-resistant infections, mostly in hospitals.

Some of the less-critical items on the WHO list involve pathogens and/or drugs of importance in animal agriculture. Several are food-borne pathogens potentially transmitted to humans through meat or dairy products, such as Staphylococcus aureus (methicillin-resistant), Campylobacter spp. (fluoroquinolone-resistant), Salmonellae (fluoroquinolone-resistant) and Shigella spp. (fluoroquinolone-resistant).

WHO developed the list to spur governments to put in place policies that incentivize basic science and advanced R&D investments into new antibiotic discovery. It will provide guidance to new R&D initiatives such as the WHO/Drugs for Neglected Diseases initiative (DNDi) Global Antibiotic R&D Partnership that is engaging in not-for-profit development of new antibiotics.

Following is the WHO priority pathogens list for R&D of new antibiotics, with three levels of priority based on the global threat level.

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

Read more from the World Health Organization.