For the first time ever, the World Health Organization has drawn up a list of the highest priority needs for new antibiotics — marching orders, it hopes, for the pharmaceutical industry.

The list, which was released Monday, enumerates 12 bacterial threats, grouping them into three categories: critical, high, and medium.

“Antibiotic resistance is growing and we are 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,” said Dr. Marie-Paule Kieny, the WHO’s assistant director-general for health systems and innovation.


“The pipeline is practically dry.”

Three bacteria were listed as critical:

  • Acinetobacter baumannii bacteria that are resistant to important antibiotics called carbapenems. These are highly drug resistant bacteria that can cause a range of infections for hospitalized patients, including pneumonia, wound, or blood infections.
  • Pseudomonas aeruginosa, which are resistant to carbapenems. These bacteria can cause skin rashes and ear infectious in healthy people but also severe blood infections and pneumonia when contracted by sick people in the hospital.
  • Enterobacteriaceae that are resistant to both carbepenems and another class of antibiotics, cephalosporins. This family of bacteria live in the human gut and includes bugs such as E. coli and Salmonella.

Notably missing from the list is the bacterium that causes tuberculosis. That was not included, Kieny said, because the need for new antibiotics to treat it has already been designated the highest priority.

Although mounting concerns about the worsening problem of antibiotic resistance have reinvigorated research efforts, producing new antibiotics is an expensive and challenging task.

The international team of experts who drew up the new list urged researchers and pharmaceutical companies to focus their efforts on a type of bacteria known as Gram negatives. (The terminology relates to how the bacteria respond to a stain — developed by Hans Christian Gram — used to make them easier to see under a microscope.)

Dr. Nicola Magrini, a scientist with the WHO’s department of innovation, access and use of essential medicines, said pharmaceutical companies have recently spent more efforts trying to find antibiotics for Gram positive bacteria, perhaps because they are easier and less costly to develop.

Gram negative bacteria typically live in the human gut, which means when they cause illness it can be serious bloodstream infections or urinary tract infections. Gram positive bacteria are generally found outside the body, on the skin or in the nostrils.

Kieny said the 12 bacteria featured on the priority list were chosen based on the level of drug resistance that already exists for each, the numbers of deaths they cause, the frequency with which people become infected with them outside of hospitals, and the burden these infections place on health care systems.

Paradoxically, though, she and colleagues from the WHO could not provide an estimate of the annual number of deaths attributable to antibiotic-resistant infections. The international disease code system does not currently include a code for antibiotic-resistant infections; it is being amended to include one.

The critical pathogens are ones that cause severe infections and high mortality in hospital patients, Kieny said. While they are not as common as other drug-resistant infections, they are costly in terms of health care resources needed to treat infected patients and in lives lost.

Six others were listed as high priority for new antibiotics. That grouping represents bacteria that cause a large number of infections in otherwise healthy people. Included there is the bacteria that causes gonorrhea, for which there are almost no remaining effective treatments.

The superbugs are growing in number and strength. Hyacinth Empinado/STAT

Three other bacteria were listed as being of medium priority, because they are becoming increasingly resistant to available drugs. This group includes Streptococcus pneumoniae that is not susceptible to penicillin. This bacterium causes pneumonia, ear and sinus infections, as well as meningitis and blood infections.

The creation of the list was applauded by others working to combat the rise of antibiotic resistance.

“This priority pathogens list, developed with input from across our community, is important to steer research in the race against drug resistant infection — one of the greatest threats to modern health,” said Tim Jinks, head of drug-resistant infections for the British medical charity Wellcome Trust.

“Within a generation, without new antibiotics, deaths from drug-resistant infection could reach 10 million a year. Without new medicines to treat deadly infection, lifesaving treatments like chemotherapy and organ transplant, and routine operations like caesareans and hip replacements, will be potentially fatal.”

The full list is:

Priority 1: Critical
1. Acinetobacter baumannii, carbapenem-resistant
2. Pseudomonas aeruginosa, carbapenem-resistant
3. Enterobacteriaceae, carbapenem-resistant, ESBL-producing

Priority 2: High
4. Enterococcus faecium, vancomycin-resistant
5. Staphylococcus aureus, methicillin-resistant, vancomycin-intermediate and resistant
6. Helicobacter pylori, clarithromycin-resistant
7. Campylobacter spp., fluoroquinolone-resistant
8. Salmonellae, fluoroquinolone-resistant
9. Neisseria gonorrhoeae, cephalosporin-resistant, fluoroquinolone-resistant

Priority 3: Medium
10. Streptococcus pneumoniae, penicillin-non-susceptible
11. Haemophilus influenzae, ampicillin-resistant
12. Shigella spp., fluoroquinolone-resistant

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  • I have Pseudomonas in my lungs. I am 66 years young and I have a lot to do before leaving this earth. I am finding the mucous produced by this infection is being coughed up quite regularly. I currently take Cflox for 4 weeks at a time but I am finding the effects on the coughing is lessening each time. Are there any foods I should be avoiding or any that could help me better manage the effects of the horrid bug?

  • What are her views on Lyme Disease weakening the immune system, allowing viruses such as Epstein-Barr to take over, potentially causing cancers? I am sick. Antibiotics are useless. I would love feedback! Thank you 🙂

    • Hi there, I have a bachelors in biology. I see there haven’t been any replies, and I would like to throw my hat in the ring. In western medicine, we attack the infection, this method was brilliantly effective until people stopped taking antibiotics for as long as they are prescribed. Now we must focus on a new method of fighting disease. This is building our own immune systems stronger. 1. The first thing that I would suggest is a 24 hour fast. This fast will be no food stuffs or any sugar intake. Drink plenty of water. Aim for 2-3 ounces of water for every 10 pounds of weight. Studies suggest that this simple fast will give the immune system a much needed rest as it will have 24 hours to not focus on the food we intake. This will allow your immune system to turn over aging or possibly defective immune cells. 2. Then following this fast, I would focus highly on fruits. These fruits must consist of a wide variety. I’m not saying cut back on food. I am saying include a citrus fruit (limes and oranges are great examples), these will fuel your macrophages. Now a caveat to add to this is that cutting out carbohydrates and sugars for a short period will allow for more effective macrophages. This has to do with the chemical structure of glucose and citric acid being only 1 hydroxide different (I believe) and that their overlap can cause some deficient macrophages. The next fruit we will want are antioxidants. Obvious ones such as grapes but also cherries, blueberries, and if you like vegetables dark green and orange vegetables are also great. Then make sure you are getting fish, I would focus on actual fish and not crustaceans and shellfish (these can be hard on a weakened immune system). This is to get omega 3s and iodide. 3. Then as a last thing to include if you can is get 5 minutes of sunlight if you have lighter skin, a medium skin tone should shoot for 5-15 minutes, and darker skin tones need to aim above 15 to possibly 25 minutes depending on tone. This is to get vitamin D production into our systems which help regulate nutrient uptake and bone health. Another item that also impacts bone health as well as overall health is a little exercise. Doing something for half an hour is good enough to help the immune system. Walking, jumping jacks, swimming, biking. Something. I hope this helps. I know lots of medical establishments that won’t push these because they cannot make money off of you if you improve your food and exercise.

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