Antibiotic-resistant bacteria: Do the old

Since biologist Alexander Fleming (1881-1955) discovered penicillin in 1928 and made it into medicine in 1943, humanity was delighted by the splendor of the "antibiotic era".

Following Fleming, many scientists were racing to research, explore other antibiotics and many inventions were published. Since then, the number of antibiotic studied has reached over 5,000 and there have been nearly 1,000 antibiotics sold in the world market.

Many old antibiotics gradually become ineffective before bacteria

Gradually, many people easily recognize famous antibiotics for a while, now the therapeutic effect has decreased significantly. Looks like the pathogenic bacteria have had time to adjust their team, train weapons to fight antibiotics, making many antibiotics disappear. Focusing on bacteria with two pieces of martial arts, that is:

Natural mutations : This is a natural transformation that occurs in the bacterial chromosome. The bacteria are dependent on their habitats for survival and development, each species of bacteria must have a complete set of enzymes to extract nutrients from the environment. If the normal habitat is altered or poisoned, many bacteria will die due to lack of enzymes to adapt. But there are also some bacteria that are able to adapt to the environment by mutating to produce new enzymes suitable for the situation.

Image describes the resistance of bacteria.

Under the action of an antibiotic dose that puts bacteria in death, most bacteria are killed, but there are a few escaping, which will survive and develop under Darwin's natural selection principle (1809). -1892). Because changes in the structure of DNA (this transformation occurs in bacterial chromosomes) will alter the structure of the protein or enzyme molecules they synthesize. If these molecules are the target of an antibiotic, this antibiotic will no longer work because the target is lost. This resistance is stable and bacteria can be passed on to future generations.

Plasmids - a special "weapon" of bacteria : Plasmids are not found in other organisms. All species of bacteria, whether round (cocci), long straight (bacillus), or twisted like springs (bacteria) . have one thing in common: it's a shell (cell membrane) ) inside contains cytoplasm and a cell nucleus. In the cell nucleus there are chromosomes and DNA. DNA carries in it the genetic properties necessary for the reproduction and nutrition of bacteria. Since 1958, Jacob and Wollman have seen bacteria also have DNA structures outside their nuclei and reproduce independently of the nucleus, called episom. Episom has 2 positions: one outside the chromosome and one merging into the chromosome. The episom never merges into chromosomes called plasmids. The nature of these plasmids is very small DNA molecules (containing few genes), ring-shaped (not rods like normal chromosomes), measuring only 0.5 - 5% of the size of the infection normal chromosomes, free distribution in cytoplasm. The production of enzymes against antibiotics is responsible for these plasmids. In the bacterial population, plasmids are transferred from this bacterium to other bacteria in a pump-like manner (phage) or incorporate two bacteria that transfer genetic factors against antibiotic genes, making the number of microbes Antibiotic-resistant bacteria increase rapidly. In 1941, all yellow staphylococcus aureus were easily eradicated by penicillin, but only three years later staph became resistant by producing a yeast (enzyme) penicilase. destroy penicillin molecule. Some other bacteria secrete beta lactamase enzymes to fight ampicillin . or acetyl transferase to fight chloramphenicol. More and more species of bacteria fend off many antibiotics. According to a report of the project to investigate the drug resistance of bacteria of the Ministry of Health, in Vietnam, the resistance of gentamycin to S.aureus was 51.6%, the resistance to norploxacin was 65.7%. E.Coli was resistant to cotrrimoxazol at the rate of 79.3%, chloramphenicol resistance was 52.6%; Cefotaxim resistant P.aeruginosa 77.3%, amikacin resistance 64.7%. Even a foreign document warns that the bacterium has also been resistant to vancomycin, an antibiotic that is considered to be the most effective currently used only when antibiotics are disabled.

The war is continuing

The antibiotic army is still large in number, but the fighting power is declining, which is the worry of no one. Two American scientists, Pandolph Nesse and George Williams (the founders of Darwin's Department of Medicine) wrote in the book Why are we sick like this: ". No man can ever win. We are much weaker than bacteria and viruses, because they are able to reproduce extremely quickly, and the evolution of bacteria in a day can go through development. that people need thousands of years. " An official report published by the WHO in mid-June 2000 also affirmed that without effective measures, there will be no more effective antibiotics in the next 20 years. However, the emergence of antibiotics, mainly because people have abused antibiotics in treatment and prevention, including the need to use antibiotics for livestock breeding indiscriminately. Therefore, proper antibiotic use is always a topical issue.

Because of the drastic antibiotic-resistant bacteria, many scientists are trying to understand the bacterial antibiotic genetic code. The most optimistic opinions are: human beings with great intelligence will defeat bacteria. With modern molecular biotechnology, it is possible to isolate neatly identified samples and identify plasmid fragments that are resistant to one antibiotic or another. Such small pieces of plasmid can be repaired by adding additional two ends. Thus, it is possible to recreate a plasmid from its fragments and thereby generate peculiar plasmids by breeding DNA of two plasmids of two different bacteria, and then recombining the obtained product into one. other bacteria. Based on the popularity of genetic rules, people have mentioned creating novel plasmids from very different bacteria to neutralize antibiotic resistance. On the other hand, by enlarging the cellular proteins 'factories', it helps to understand the mechanism of genetic transcription into proteins, thereby understanding the effects of many antibiotics and the basis of some types. Drug resistance of bacteria. The most profound purpose of the above is to understand the genetic code of enzyme production against bacterial antibiotics, to find ways to neutralize resistance or to find new antibiotics that are particularly effective. but bacteria are hard to resist.