Wednesday , December 8 2021

Why are bacteria resistant to antibiotics?


"My throat hurts and I have some fever, I'll take this antibiotic when I was the same one year ago." This is the wrong thinking of the people who decide self-medicated with these drugs rather than contrasting with a doctor what they have.

This thought goes on with that Nearly 20% of pharmacies still deliver non-prescription antibiotics, according to a study by Maruxa Zapata-Cachafeiro and her team published in November in November Journal of Antimicrobial Chamotherapy. It is also important to remember that Royal Decree 1/2015 prohibits giving antibiotics without a prescription. But why is it forbidden? What is antibiotic resistance? Why does it hurt us?

To answer all of these questions, you must go back to that moment Alexander Fleming He made his biggest discovery (and that of humanity): penicillin. So far, any infection may take the patient forward. "The greatest killer in history, the plague, is an uncontrolled bacterium," said Bruno González-Zorn, a researcher at the Complutense University of Madrid. However, the body's immune system can cope with bacteria, but the use of antibiotics has meant it Deaths from bacterial infection are not as frequent as they were until penicillin arrived.

Fleming's penicillin

Fleming was lucky. One day he decided to leave the window in his laboratory open while on a trip. On return, A curious thing had happened. His plates, where he studied the bacterium Staphylococcus aureus, had been colonized by a sponge, it Penicilliumnotatum. Then he could have thrown the Petri dish in the trash, but he did not realize that there was an area between the bacteria and the fungus where the first one had not even developed. This was due to the antibiotic ability of the fungus, so it became the detective of penicillin, from the fungus.

However, it was not Fleming who isolated the active ingredient of antibiotics. Before the urgency of World War II did not occur, scientists could not synthesize it. Only then, with the echo of the bullets and the death of infections, Ernst Boris Chain and Howard Walter Florey they could synthesize it and thus saved many lives. Due to the importance of both the discovery and its synthesis, the three researchers received the Nobel Prize in Medicine when the war ended in 1945.

At that time not only did the massive use of antibiotics begin, which helped to increase life, but also began to look for other fungi such as natural form was antibiotic. Then the golden age of antibiotics was produced: it was used continuously and there were new every day. But from the 70's of last century, find new molecules that end up with Bacteria become harder and harder and unprofitable for pharmaceutical companies, why they gradually abandon their search.

Resistance to antibiotics

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Soon you will see that some bacteria become resistant to drugs and over time, resistance increases, especially today. "Last year, we treated a patient with HIV who received pneumonia, and the bacteria were resistant to all antibiotics," explains Jaime Esteban, a microbiologist at the Fundación Jiménez Díaz Hospital in Madrid, and secretary of the Board of Spanish Society of Communicable Diseases and Clinical Microbiology (SEIMC). In the case of immunosuppressed persons, such as a patient with HIV, someone who has only had organ transplants or who is chemotherapy or radiation therapy, it is a death sentence because there is no drug to treat the infection, and even your immune system can defend itself .

"You have to look at Darwin to understand what happens to the bacteria"

But what happens to the bacteria becoming resistant? "You have to look at Darwin to understand what's happening"says Esteban. Natural selection has some blame in the bacterial resistance to these drugs. If there are four bacteria in your body and two of them die because of the antibiotic, there are two more. You will be resilient and the other will be sensitive, even if it will not disappear. In addition, the one who is resistant "will pass on his genetic material to the other bacteria and everyone will have resistance mechanisms," commented Gozález-Zorn. And then they put up and put on resistant bacteria until the sensitive disappear. This situation can be reversed if we get the sensitive bacteria to go there that they do not die because they defense mechanisms "are very expensive"that is, it costs them energy.

"Bacteria have been in contact with natural antibiotics for thousands of years and They have developed many mechanisms against them"commented on both González-Zorn and Esteban. The ways in which bacteria defend themselves are several, breaking the molecule or removing the molecule from its interior or changing the target, that is to say, bacteria "mutate" so that the molecule does not recognize it and it does not matter to him.

One of the biggest problems today is that these resistance mechanisms are not performed only with an antibiotic but with everything we use. There are already multiresistant bacteria, says Esteban, and this means that each time we have fewer options to end them and increase the number of deaths due to resistant bacteria. It has actually begun to happen: in May of the same year, the expert already warned 35,000 people die in Spain because of resistance to antibiotics. Although experts do not agree if they point out that it is a figure similar to that that would be produced each year at European level. It is that this type of multiresistant microbes kills more people than road accidents nationwide, which usually is an average of 1,200 people each year.

"In some cases, we had to use colistin, which is last resort"Because it causes kidney damage, according to Esteban, this antibiotic is also used by animals for the same reasons: in order to avoid resistance to this drug in Spain, the use of colistin in pigs has decreased since 2015 when it was 51% and now it's 9%, as explained Hipertextual Gonzalez-Zorn.

Incorrect use of antibiotics

To store antibiotics at home or buy them without a prescription is also from The main causes of bacteria becoming resistant. Therefore, the importance of taking only these drugs if prescribed by doctors, but why?

Not all bacteria are the same or affect the same drug, so it is important to go to the doctor to carry out the necessary tests to identify the microbial which causes the condition, which may be a bacterium, yes, but also a virus, a fungus or a parasite. And the treatment is not the same for everyone. It's also not the same if you have breathing or urinary infection, so it will not be the same medicine used.

With the analysis or culture of the combined tests, the microbiologist will know the type of bacteria, but also if it is resistant to an antibiotic. In this way, treatment becomes more effective because the most appropriate and No resistance to other drugs will be created. In addition, it is important to complete medical treatment properly as well, because if it is not done properly, the infection may appear again.

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