The most dangerous resistant bacteria for human health

human-resistant bacteria

The World Health Organization (WHO) has published its updated compilation of priority bacterial pathogens for 2024. This list, of vital importance for global health, includes 15 families of antibiotic-resistant bacteria, classified into three groups. This categorization is intended to streamline the prioritization process and facilitate the development of new treatments aimed at combating the growing threat of antimicrobial resistance.

In this article we are going to tell you what the resistant bacteria most dangerous to human health.

antibiotic resistance

resistant bacteria

Antimicrobial resistance occurs when bacteria, viruses, fungi, and parasites develop the ability to resist the effects of drugs that were once effective against them. This phenomenon translates into more severe diseases that are more difficult to treat, increasing the possibility of spread and transmission in the population. This results in higher morbidity and mortality rates. The main cause of this worrying increase in resistance is the excessive and inappropriate use of antimicrobials.

To combat this threat, the WHO has updated its list of priority pathogens, integrating new evidence and knowledge provided by experts. This list not only guides the research and development of new antibiotics, but also promotes international collaboration and innovation in the field.

Classification of priority pathogens


The list of pathogens is divided into three priority groups:

  • Critical
  • Alto
  • Medium

This classification is based on several factors, including the global prevalence of infections caused by drug-resistant bacteria and the implications for public health. The list becomes an essential tool for directing resources towards the development of new antibiotics and improving their accessibility, facing the challenges that slow progress in this field.

The development of new antibiotics is crucial to address the threat of antimicrobial resistance. However, this process faces multiple obstacles. These include the high costs of research and development, the long time required to test and approve new drugs, and the financial risk involved.

Fostering international collaboration

To overcome these challenges, it is essential to foster international collaboration. WHO plays a central role in coordinating global efforts, facilitating the exchange of knowledge and resources between countries and organizations. This cooperation is vital to accelerate the development of new treatments and ensure they are available worldwide.

In addition to collaboration, innovation is a key component in the fight against antimicrobial resistance. Research into new classes of antibiotics and alternative therapies needs to be encouraged. Financial incentives and supportive policies can play a significant role in encouraging pharmaceutical companies and researchers to invest in this critical area.

Antimicrobial resistance has a significant impact on public health. Drug-resistant infections are more difficult to treat, resulting in longer hospital stays, higher medical costs, and higher mortality. Additionally, resistance can make routine medical treatments, such as surgeries and chemotherapy, riskier due to the increased risk of infections.

Surveillance and prevention are essential elements to control the spread of antimicrobial resistance. WHO recommends the implementation of robust surveillance programs to monitor resistance and detect emerging patterns. These programs should be accompanied by prevention strategies, such as promoting appropriate antibiotic use and implementing good hygiene practices in healthcare settings.

Education and public awareness are also very important. It is necessary to educate the population about the dangers of antibiotic misuse and promote responsible practices. Healthcare professionals should be continually trained on the latest guidelines and protocols for antimicrobial use.

List of priority pathogens according to the WHO in 2024

The most dangerous resistant bacteria for human health

The updating of the list of priority pathogens by the World Health Organization is an essential step in the fight against antimicrobial resistance. This list not only provides clear guidance for the research and development of new treatments, but also emphasizes the importance of international collaboration and innovation. By addressing the challenges of antimicrobial resistance comprehensively, significant progress can be made to protect public health globally.

The WHO list of priority bacterial pathogens for 2024 includes these bacteria:

Critical priority:

  • Carbapenem-resistant Acinetobacter baumannii
  • Enterobacteriaceae resistant to third generation cephalosporins
  • Enterobacteriaceae resistant to carbapenems
  • Rifampicin-resistant Mycobacterium tuberculosis (which has been included after carrying out an independent analysis with parallel adapted criteria and after the subsequent application of an adapted analysis matrix to decide based on several criteria).

High priority:

  • Salmonella Typhi resistant to fluoroquinolones
  • Shigella spp. resistant to fluoroquinolones
  • Vancomycin-resistant Enterococcus faecium
  • Carbapenem-resistant Pseudomonas aeruginosa
  • Fluoroquinolone-resistant non-typhoid salmonellae
  • Neisseria gonorrhoeae resistant to third generation cephalosporins and/or fluoroquinolones
  • Methicillin-resistant staphylococcus aureus

Medium priority:

  • Macrolide-resistant group A streptococci
  • Macrolide-resistant Streptococcus pneumoniae
  • Ampicillin-resistant Haemophilus influenzae
  • Macrolide-resistant group B streptococci

Why do they become resistant?

There are numerous reasons why bacteria become resistant to antibiotics:

Mutation and natural selection:

  • Bacteria are microorganisms that reproduce quickly. Over generations, some bacteria acquire mutations in their DNA.
  • When exposed to antibiotics, bacteria that have favorable mutations to resist the drug survive, while sensitive ones die.
  • Over time, these mutations accumulate, creating resistant strains.

Gene transfer:

  • Bacteria can also transfer resistance genes to each other. This occurs when one bacteria captures DNA from another.
  • If a resistant bacteria transfers its genetic material to a sensitive one, the second one also becomes resistant.

Inappropriate use of antibiotics

  • The massive and incorrect use of antibiotics accelerates this process. Self-medication or incomplete treatments are examples.
  • The bacteria adapt, developing a multi-resistant “super shield” that can repel several drugs simultaneously.

I hope that with this information you can learn more about the resistant bacteria that are most dangerous to human health.

Leave a Comment

Your email address will not be published. Required fields are marked with *



  1. Responsible for the data: Miguel Ángel Gatón
  2. Purpose of the data: Control SPAM, comment management.
  3. Legitimation: Your consent
  4. Communication of the data: The data will not be communicated to third parties except by legal obligation.
  5. Data storage: Database hosted by Occentus Networks (EU)
  6. Rights: At any time you can limit, recover and delete your information.