In an effort to jumpstart and guide new antibiotic development, the World Health Organization (WHO) has released a list of antibiotic-resistant priority pathogens that agency officials believe are the greatest threat to human health and should be the target of research and development. The list is divided into three categories according to the urgency of need for new antibiotics: critical, high and medium priority.
The most critical group of all includes three types of gram-negative bacteria that are resistant to multiple antibiotics, including the last-resort carbapenems: carbapenem-resistant Acinetobacter baumanni, carbapenem-resistant Pseudomonas aeruginosa, and carbapenem-resistant, extended-spectrum beta lactamase (ESBL)–producing Enterobacteriaceae. These pathogens can cause severe and often deadly bloodstream and urinary tract infections in hospital patients who have weak immune systems and require invasive devices such as ventilators and catheters.
Pathogens in the high-priority category—which can cause hard-to-treat infections in healthy people but generally don't have a high mortality risk—include vancomycin-resistant Enterococcus faecium, methicillin-resistant Staphylococcus aureus (MRSA), and fluoroquinolone-resistant Salmonella. Neisseria gonorrhea, a sexually transmitted infection that's becoming increasingly resistant to its main treatment options, is also in this category.
Pathogens in the medium-priority category include Streptococcus pneumoniae and Shigella spp. These bacteria still have some effective antibiotic options but are becoming increasingly resistant. While less dangerous than the critical pathogens, they are also more widespread in the community, especially in nursing homes, where there is more uncontrolled usage of antibiotics, WHO explains.
Link to WHO’s press release: http://www.who.int/mediacentre/news/releases/2017/bacteria-antibiotics-needed/en/