Let's talk about antibiotics and whythey must be taken strictly as prescribed by the doctor. The World Health Organization (WHO) has included the problem of the emergence of antibiotic-resistant bacteria in the list of serious threats facing humanity. Antibiotic resistance today causes the death of about 700,000 people a year, while complicating the treatment of numerous infections, including pneumonia, tuberculosis and gonorrhea. If scientists do not find a way to combat these bacteria, the number of victims from preventable diseases today could reach 10 million deaths per year by 2050.
Why did antibiotic resistant bacteria appear?
Widespread useantibiotics worldwide are largely due to the emergence of antibiotic-resistant bacteria, which are currently one of the most serious health risks. Bacteria, like other organisms on our planet, seek to survive at all costs. After the discovery of penicillin, the life of many bacteria became much more complicated. To continue its existence, some bacteria acquired antibiotic resistance through changes in the genome.
Today, some bacteria are even capabledestroy antibiotics. They also cease growth and division. This behavior of bacteria makes it difficult to detect for the immune system. However, a new study by scientists published in the journal Nature focuses on the little-known method that bacteria use to achieve antibiotic resistance. Researchers were able to show that bacteria can “change shape” in the human body to avoid exposure to antibiotics - this process does not require genetic changes, contributing to the growth of bacteria.
How do antibiotics kill bacteria?
Almost all bacteria are surrounded by structure,which is called the cell wall. The wall is like a thick shell that protects bacteria from external influences. The wall also gives the bacteria the correct shape (for example, sticks or spheres) and helps them share effectively. But human cells do not possess such a “shell”. Because of this, the immune system easily recognizes dangerous bacteria - their cell wall is very different from all other cells. For the same reason, the cell wall is the target of the most commonly used antibiotics, such as penicillin. Thus, antibiotics, whose work is aimed at finding bacteria with a “shell”, can kill bacteria without causing any harm to humans.
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However, scientists are aware of bacteria,able to survive without a cell wall. If the surrounding conditions are able to protect the bacterium from aggressive environmental influences, the bacteria can turn into the so-called "L-forms", that is, bacteria without a cell wall. Such bacteria were discovered in 1935 by microbiologist Emmy Klienberger-Nobel and were named after the Lister Institute for Preventive Medicine.
The video below shows how bacteria change shape.
To create a protective environment for bacteria inlaboratories, scientists often use sugar. Such changes inside the human body, as a rule, are caused by antibiotics that affect the cell wall of bacteria or certain immune molecules, for example lysozyme - it helps protect the eyes from bacterial infections and is present in the tear. Bacteria without a cell wall often become fragile and lose their shape. However, they also become partially invisible to our immune system and therefore are completely resistant to all types of antibiotics, the action of which is aimed at finding and destroying bacteria with a cell wall.
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Scientists have long suspected a change in shapebacteria can contribute to recurrent infections by helping bacteria hide from the immune system and resist antibiotics. However, evidence for this theory was very difficult to find because of the elusive nature of L-forms and the lack of appropriate methods to detect them.
In what environment do bacteria change shape?
The study examined the types of bacteriaassociated with recurrent urinary tract infections (UTIs). It was found that many types of bacteria, including Escherichia coli and enterococcus, can survive as L-forms in the human body. Scientists have discovered these bacteria using fluorescent probes that recognize bacterial DNA.
During the study, scientists tested the samples.urine of elderly patients with recurrent UTIs, growing them in a high sugar Petri dish. This medium not only helped protect the bacteria, but also isolated the L-shaped bacteria that were present in the samples. Experts note that according to the results of the study, antibiotics must be tested under conditions similar to those in the human body. The conditions that are currently used in medical laboratories do not provide sufficient protection for the survival of bacteria of delicate L-forms.
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Experts hope that the results obtained inthe future will help find a way to fight antibiotic-resistant bacteria. Combining active cell wall antibiotics with antibiotics that kill L-forms can be one way to fight infections. So our battle with the bacteria continues.