Natural killer cells could successfully fight the super bacillus Klebsiella

Physicians study how immune cells communicate when infected by Klebsiella

There is a serious global threat to human health from so-called multi-drug resistant bacteria. Klebsiella pneumoniae is a causative agent of pneumonia and septicemia, which is often associated with resistance and where treatment options are severely limited or may even be completely impossible to treat. Researchers now found out how immune cells communicate at the site of infection and then join forces in the fight against Klebsiella. This could open up alternative therapies for pathogens that have been found to be ineffective against existing antimicrobial drugs.

The scientists of the University of Vienna, the Medical University of Vienna and the Queen's University Belfast found in their current study how immune cells communicate at the site of the infection and join together in the fight against Klebsiella. The results may be used in the future to develop therapies that are an alternative to ineffective antimicrobial drugs. The experts published the results of their study in the English-language journal "PLOS Pathogens".

Infections with multidrug-resistant microbes are becoming more common. Klebsiella belongs to these microbes and can lead to fatal lung diseases and blood poisoning. (Image: freshidea / fotolia.com)

Excessive use of antibiotics leads to dramatic consequences

Klebsiella can cause fatal pneumonia and toxemia, with few treatment options available. Sometimes a treatment is completely impossible. One reason for the emergence and spread of multidrug-resistant microbial pathogens in recent decades has been the inappropriate or excessive use of antibiotics. According to the European Center for Disease Prevention and Control, around 25,000 people in the EU die each year from infections with multidrug-resistant bacteria. Worldwide, antimicrobial resistance even causes 700,000 deaths per year.

WHO warns of super bacilli

The World Health Organization (WHO) warned at the beginning of the year of antibiotic resistance so-called super bacilli. These bacteria are resistant to several different antibiotics, which leads to a huge risk to human health. Klebsiella is one of them. This bacterium can cause serious and often fatal infections of the bloodstream and lungs. Klebsiella is resistant to common types of antibiotics. In addition, the bacterium is also highly resistant to carbapenems. These are, so to speak, the last resort for the treatment of severe nosocomial infections.

Immune cells communicate with each other

The scientists discovered in their study how immune cells communicate at the site of infection and then band together to eradicate Klebsiella during pneumonia. The study's findings indicate that future therapies for severe Klebsiella infections may target the host's immune system rather than the pathogen itself, the experts explain.

Natural killer cells keep bacterial growth at bay

So-called natural killer cells can curb the growth of Klebsiella during pneumonia. The researchers were now able to identify the mechanism for this. Klebsiella activates critical regulators of the immune response, the so-called type I interferons (IFNs), which mediate between macrophages and natural killer cells. Type I interferons thus help to activate natural killer cells. The killer cells then allow the macrophages to start an antibacterial program, explain the doctors.

Type I IFNs conduct the defense against bacteria, so to speak

"Type I IFNs are used by the immune system to deliver messages between immune cells to orchestrate a perfect defense. Natural killer cells are the conductors of the defense orchestra, while macrophages are the tools that kill bacteria, "explains Masa Ivin, first author of the study and doctoral student in the Kovarik laboratory in a press release from the University of Vienna.

Will there be new therapies for multi-drug resistant germs in the future??

The findings from the study may lead to the development of new therapies for multidrug-resistant bacteria in the near future. "If drugs can not kill the pathogen, we should help the immune system get the job done. In our current study, we identify new and feasible ways to support the immune system in the fight against super bacilli, "explains author Pavel Kovarik. (As)