The emergence of drug-resistant bacteria is associated with the long-term widespread use of antibiotics, especially antibiotic abuse. This is easy to understand. Because of the large-scale abuse of antibiotics and the low-dose use of antibiotics, bacteria that have been resistant to the drug-resistant bacteria have been killed, making the drug-resistant bacteria have a survival advantage. But only so, the problem of bacterial resistance is not so serious, the real cause of the spread of drug-resistant bacteria is the gene exchange between bacteria.
The formation of antibiotic-resistant bacteria first benefits from the variation of the bacteria themselves. The bacterial gene variation ratio is about 3%, which is a mistake that microbes, such as low-level organisms, make during gene synthesis. Most of these mutations are not good or even harmful to the bacteria themselves, and these unhelpful mutations are either not preserved or not noticed. A small percentage of the genetic variants are beneficial mutations, about 0.5%. Many of these genetic variants are drug-resistant genetic variants that allow bacteria to resist the toxicity of antibiotics, so they can enhance their ability to survive and adapt to bacteria.
Bacteria can not only exchange genes between the same species, but also exchange genes between the same genus, between the same family, between the same subject and between the same door, that is, the bacteria can be exchanged between the bacteria in the world.
One of the concerns about GM safety is this gene exchange, but there is no need to worry about it. Because human genetic exchange can only be through reproduction and is limited to the same kind. There is no genetic exchange between humans and orangutans, not to mention the exchange of monkeys with the same purpose. Half-human and half-monkeys, half-human and half-orangutans are unlikely to occur. Animals that are slightly more advanced will not receive foreign genes so casually, and only low-level organisms such as bacteria can carry out such extensive gene exchange.
Because of the ability to exchange genes, the main pathway for bacteria to acquire resistance is not necessarily the mutation of their own genes but can be obtained by exchanging genes. Once a drug resistance gene exists in the bacterial world, it may be widespread through gene exchange, which is equivalent to an epidemic. This is the most terrible thing for drug-resistant bacteria.
Bacterial gene exchange has many unexpected points. For example, scientists have found that rainwater rushes resistant bacteria into wetlands and exchanges genes with bacteria that live there, making many naturally occurring bacteria resistant to antibiotics. If there are bacteria that are deadly to humans, it will become a dangerous danger. If a person is infected with such drug-resistant bacteria, it is likely that there is no cure.
In addition to this natural bacterial resistance gene exchange, there are also gene exchanges in the human body. There are various bacteria in the human intestines. After the baby is born, the bacteria will be taken from the mother and the environment to form their own intestinal flora. The formation of intestinal flora takes 2 to 3 years. If infants and young children use antibiotics excessively, drug-resistant bacteria will be present in the intestines of children in the case of more and more drug-resistant bacteria and may dominate by gene exchange. Although these bacteria are harmless to the human body, pathogenic bacteria are formed in the human body when pathogenic bacteria enter the intestine and exchange genes with the resistant intestinal flora.
Staphylococcus aureus is present in the human body, and most of them are harmless. Many people with MRSA infection are asymptomatic. Of the severe MRSA infections, 90% are infected by exposure to asymptomatic carriers. The infection is mainly in the family, followed by the school, so controlling MRSA infection and spread should start from daily life.
Another source is livestock. Studies have found that people who are exposed to livestock, poultry or farming are more likely to carry resistant bacteria. Pig manure is also an important source, so the use of farmyard manure will spread resistant bacteria. Because livestock and poultry are fed a large number of antibiotics, drug-resistant bacteria appear; while livestock and poultry live in crowds, making drug-resistant genes widely available in animals. Some of these resistant bacteria can be transmitted to humans through contact or through animal droppings, which can cause human disease.
To solve this source of transmission, it is necessary to avoid the abuse of antibiotics in the breeding industry. The 8% of antibiotics produced in the United States are used in the breeding industry, and the situation in China is even more serious. At present, relevant experts call on the FDA and other departments to legislate, do not feed antibiotics to animals that are not sick, because this is a huge threat to human health. But doing this is not a one-off effort. Faced with this situation, the use of farmyard manure organic agriculture has become an inevitable way for drug-resistant bacteria to pass from animals to humans.
Drug resistance genes are a way for bacteria to adapt to the environment and are the result of the emergence of antibiotics. After decades of incubation and development, the problem of drug-resistant bacteria has reached the eve of a major outbreak. The future of humanity against infectious diseases is overcast, and resistant bacteria are a serious health problem for us and our next generation.