On the eve of the war against microbial resistance, scientists invented a previously unknown cyclic peptide from the bacteria Stapylococcus lugdunensis that dwells in human nose.

Antibiotic resistance is a growing problem for physicians. There are estimates which suggest that more people will die from bacterial resistance in the coming decades than cancer. New antibiotics are in huge need because the world is running out of these life-saving drugs.

Antibiotic resistance emerged as a result of superbugs, which are very tough to cope with. Usually, changes in the genetic code of bacteria are those that mostly contribute to the development of antimicrobial resistance. One of the most important factors that lead to antibiotic resistance is the improper use of antibiotics. 

Wondering about the future of our health, which is now threatened by the lack of proper antibiotics, scientists isolated an antibiotic called Lugdunin from the strain of bacteria named Staphylococcus lugdunensis that resides in human nose. Lugdunin is an antibiotic compound, a thiazolidine-containing cyclic peptide. It is a non-ribosomally synthesized cyclic peptide that inhibits growth of Staphylococcus aureus strain.

Researchers from the Institute of Organic Chemistry at the University of Tübingen closely examined the structure of Lugdunin and discovered that it consists of a previously unknown ring structure of protein blocks and thus established a new class of materials.

Most of the time, Saureus is harmless but occasionally, it causes severe, even life-threatening disease—for instance when it gets into an open wound and causes sepsis. S.aureus is a notorious hospital dweller, and its drug-resistant form, known as MRSA (for methicillin-resistant Staphylococcus aureus) is a major public health problem resulting in the death of more than 10,000 people a year in the United States alone.

Scientists have discovered that Staphylococcus lugdunensis which colonizes in the human nose produces a previously unknown antibiotic. As tests on mice have shown, the substance which has been named Lugdunin is able to combat multi-resistant pathogens for which classic antibiotics have resulted ineffective. It reduced or even eradicated the infection. 

Infections caused by antibiotic-resistant bacteria, like the pathogen Staphylococcus aureus (MRSA), which colonizes on human skin are among the leading causes of death worldwide. The natural habitat of harmful Staphylococcus bacteria is the human nasal cavity.

What makes lugdunin remarkable is not only its ability to kill a wide range of bacteria in animal tests — it is approximately as powerful as vancomycin, a drug used to treat life-threatening infections that do not respond to other antibiotics — but also the way it keeps on working without inducing drug resistance. The action of Staphylococcus lugdunensis could be understood as a manifestation of biological antagonism, where microbes compete with each other for survival. 

                               Strains of bacteria from Staphylococcs species that are normally present in human nose.

Normally antibiotics are formed by soil bacteria and fungi. This discovery proves that human microflora may also be a reach source of antimicrobial agents is a new discovery. In future studies, scientists will examine whether Lugdunin could actually be used in therapy. One potential use is introducing harmless Lugdunin-forming bacteria to patients at risk from MRSA as a preventative measure because Slugdunensis. It is also important to state that Slugdunensisis associated with a range of infections—including of the heart, joints, skin, and eyes.

Further research in medicinal chemistry and pharmacology will be warranted to optimize the molecular structure, including making the compound more soluble in water and yielding useful derivatives, before clinical trials in humans.

After Teixobactin, Lugdunin seems to be the most serious antimicrobial discovered in recent years that could inspire many scientists to find appropriate antibiotics that are more effective than classic ones. Most likely, there are many other unexplored microbes in our body that dwell inside us, which could produce natural compounds capable to cope with superbugs.

They did not see MRSA develop any resistance to Lugdunin, although this is a probably event.

This discovery does not solve the problem of a lack of systemic antibiotics, but provides a potentially useful tool for decolonizing S. aureus and finding additional antibiotic-producing symbionts to suppress pathogens in the human microbiome.

 

COPYRIGHT: This article is property of We Speak Science, a nonprofit institution co-founded by Dr. Detina Zalli (Harvard University) and Dr. Argita Zalli (Imperial College London). The article is written by Vedat Sunguri ( Master of Pharmacy, University of Pristina) .

REFERENCES:

  1. http://www.independent.co.uk/news/science/antibiotic-resistance-new-drug-nose-mrsa-superbugs-lugdunin-a7160131.html,
  2. http://www.sciencemag.org/news/2016/07/new-antibiotic-found-human-nose,
  3. http://www.nature.com/news/the-nose-knows-how-to-kill-mrsa-1.20339,
  4. http://www.sciencemag.org/news/2016/07/new-antibiotic-found-human-nose,
  5. http://www.rsc.org/chemistryworld/2016/07/new-antibiotic-nose-bacteria-human-microbiome,
  6. http://www.popsci.com/antibiotic-that-fights-mrsa-discovered-in-human-noses,
  7. https://next.ft.com/content/25f942ee-53f6-11e6-9664-e0bdc13c3bef,
  8. http://time.com/4426641/antibiotic-nose-super-bug/,
  9. http://www.npr.org/sections/health-shots/2016/07/27/487529338/nose-y-bacteria-could-yield-a-new-way-to-fight-infection.