The drug-resistant bacteria that pose the greatest health threats

The World Health Organization (WHO) has for the first time released a list of drug-resistant bacteria that pose the greatest threat to human health — and for which new antibiotics are desperately needed. The agency’s aim in listing these ‘priority pathogens’ is to steer funds towards development of the most crucial antimicrobials. Researchers say the list is a useful reminder of the danger of bacteria that are becoming resistant to antibiotics.

The list ranks 12 bacteria or bacterial families and is topped by carbapenem-resistant Acinetobacter baumannii. This obscure bacterium causes a severe infection for which almost no treatments exist, and mainly affects people who are already critically ill. (It is resistant to carbapenem antibiotics, a ‘last resort’ antibiotic used only when all other treatments have failed.) The ranking also includes well-known bacteria, such as those that cause  pneumonia and gonorrhoea (see ’Threat list’).

Antibiotic resistance kills an estimated 700,000 people each year worldwide, and some experts predict that number to reach 10 million by 2050 if efforts are not made to curtail resistance or develop new antibiotics. Despite an urgent need for these drugs, the once-robust development pipeline for antibiotics now produces little more than a trickle of compounds. As of September 2016, about 40 new antibiotics were in clinical development for the US market, compared with hundreds of cancer drugs.

Carbapenem-resistant Acinetobacter baumannii tops the the World Health Organization’s 'priority pathogens’ list. CDC/Science Photo Library