A list of pathogens sets priorities for antibiotic research

Pseudomonas was included in the critical priority group.

© CDC_Janice Haney Carr

The spread of antibiotic resistant bacteria is causing concern—and the call for new agents is getting louder and louder. But which antibiotics are needed most urgently? Today, for the first time, the World Health Organisation (WHO) has published a list of 12 bacteria groups which are to be given priority for future new antibiotic research and development. DZIF scientists at the University of Tübingen were substantially involved in developing this priority list. We spoke with the head of the group, Prof Evelina Tacconelli, about how the list was developed and the aim of the selections. 

What exactly is this Priority Pathogen List?

Evelina Tacconelli: Since the 2015/16 G20 Summit, antibiotic resistance has been at the very top of the German Minister of Health’s agenda. For this reason, the Ministry requested the WHO to develop a priority list. This list is to illustrate which new antibiotics need to be developed with critical priority and the pathogens they should target. Germany, in collaboration with other countries, has the task of establishing an economic programme for promoting antibiotic research. To this effect, it is important to understand beforehand where, and for which microorganisms, the money should be invested. The problem is that the pharmaceutical industry is currently not interested in investing in new antibiotics because they are not economically attractive. This makes the Priority List particularly important: with it, the WHO makes concrete recommendations as to where funding should be allocated.

How were the most important pathogens selected?

Evelina Tacconelli: I am very proud of the method we used to develop the list—a so-called “Multi Criteria Decision Analysis”. Using this new method, we linked evidence-based data with expert opinions. We initially conducted literature and project research on the evidence for nine criteria, for example, “mortality”, “hospital and societal burden”, “transmissibility”, and “preventability”. Subsequently, we presented this evidence to 70 experts from the six WHO regions, without disclosing the bacteria’s names. The experts gave their opinions on where the priorities should be set. Finally, we derived the final list from this data using statistical methods. 

Does it involve predominantly hospital pathogens or all antibiotic-resistant bacteria?

Evelina Tacconelli: We included all antibiotic-resistant bacteria from which we finally selected 12 groups of bacteria. We divided these pathogens into three priority groups: those with critical, high and medium priority. As expected, bacteria such as Acinetobacter, Pseudomonas and different Enterobacteriaceae like E.coli, which are a threat in hospitals, were included in the critical priority group. Others, such as gonococci and Salmonella, were classified as high risk.

For whom was the list developed?

Evelina Tacconelli: Target groups include the pharmaceutical industry and all research establishments that develop new antibiotics—and many of these exist in Germany. We are talking to the private sector, as well as universities and large research groups that are now planning for the next 15 years. The idea is that, on a national level, the health ministers decide to invest precisely for this purpose, and consequently create incentives for those who develop antibiotics against the listed bacteria in the coming years. In the next five years, incentives for research on multidrug-resistant Gram-negative bacteria should be given higher priority. Up to now, many antibiotics against Gram-positive bacteria, such as MRSA-strains, have been developed, but they no longer constitute the main problem.

What to you hope to achieve with this list?

Evelina Tacconelli: I believe that this year is the right time for it. For the first time, we are talking about the funding needed to rectify the problem of antimicrobial resistance. Everyone knows: the mortality needs to be reduced but that this is also a major economic issue. For this reason, establishing a plan precisely now, to tackle the growing antimicrobial resistance problem in future and for the targeted development of new antibiotics, is important. I am convinced that that the pharmaceutical industry will take this list into consideration for their planning.

Who was involved in developing the list?

Evelina Tacconelli: My group collaborated with WHO experts, whereby we led the projects in Tübingen. We had a “Coordinating Board” with eight experts from different countries. Beyond this, we involved eight experts from major stakeholders, for example the ECDC, EMA, FDA, NIH and CDC, and an additional 70 experts from Europe, America, Asia, Africa and Australia.

Do DZIF projects already exist that take these prioritised organisms into account?

Evelina Tacconelli: The DZIF research field “Novel Antibiotics” concentrates on this. We have discussed this list with many DZIF colleagues. There are a series of DZIF projects, alongside others, which are already conducting research on these prioritised organisms. I hope that this list will influence further prioritising at the DZIF as well. This is a good example of translational research at the DZIF: the clinicians identify where the problems lie and we work together with experts from basic research to finally develop new therapeutic agents.

WHO Priority Pathogen List press release

Full WHO report

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