Human antimicrobial resistant bacteria
04 years http://www.sina.com.cn 2009 on 19 day Beijing 00:17


 
 

The discovery of penicillin started between humans and bacteria, "protracted war" the first shot.
 
 

The emergence of drug-resistant bacteria, to a large extent related to the abuse of antibiotics and human.

TB was once the largest killer of mankind, but with the extensive use of antibiotics, tuberculosis fall hazards in the sixties and seventies of the last century quite human "victory" feeling. However, in the last century, but tuberculosis resurgence, pick-up in a straight line the epidemic, a great back, "the first killer" of potential locations, and most worrying, is the resistance of the large number of TB cases.

1 drug resistance led to the treatment of difficult

The last century since the 90's, the global TB epidemic rise significantly, the World Health Organization believes that the main reason for recovery include: blind optimism, relaxation of the tuberculosis control work; increase in immigrants and refugees, the majority of these immigrants and refugees have been infected with the TB incidence a high rate of incidence increased their local prevalence of TB; HIV infection reduces the body immunity against Mycobacterium tuberculosis.

And most important, is a multi-drug-resistant TB cases increased, the pulmonary tuberculosis patients a wide range of anti-tuberculosis drug resistance occurred.

TB drug resistance is divided into single-drug resistance, multidrug resistance, MDR, MDR-serious levels of these. The reason why such resistance at the level of treatment of tuberculosis because there are levels of the drug. Medical treatment of tuberculosis to first-and second-line drugs are divided into two broad categories.

Tuberculosis control in China CDC Director of the Office of Clinical Center, Liang said that the best first-line drugs, and cheap side effects, treatment will be the first to use, if invalid, then the use of second-line drugs. This is like attacking the enemy, precision air strikes to start, if not destroy the enemy, but to put ground forces.

First-line drugs, including isoniazid and rifampicin equality, there is relatively good for TB treatment. And second-line drugs including fluoroquinolone antibiotics, such as for example ofloxacin.

TB drug resistance is divided into levels according to the level of these drugs, single drug-resistant TB is on a first-line anti-tuberculosis drug resistance; multi-drug-resistant TB is more than one line of anti-tuberculosis drug resistance; MDR Mycobacterium tuberculosis drug refers to at least isoniazid, rifampicin resistance; serious means of multi-drug resistant Mycobacterium tuberculosis infection in patients with the exception of at least two main first-line anti-TB drugs isoniazid, rifampicin resistance, but also on the injection of three second-line anti-tuberculosis drug resistance in at least one.

Treatment of drug-resistant TB takes charge of a large amount of money, the general treatment of TB costs only 150-200 yuan per person; and MDR-TB treatment costs, per person needs 15000-20000 yuan. TB patients unable to pay medical expenses due to the interruption of treatment, are not uncommon in clinical practice. And a large number of side-effects of medication on the patient's body a great deal of harm and, more importantly, is likely to use no matter how, we can not kill the TB patients, and ultimately cause deaths.

Two have been competing for a long time magic

So, why have drug-resistant TB do?

In 1928, the United Kingdom Alexander Fleming accidentally discovered in a Petri dish growth area Penicillium bacteria can not grow, which led to the discovery of actinomycin Green and has no intention of opening a Darwinian evolution of medical practice in large-scale a prelude to use.

Scientists believe that the reason why the majority of the most effective antibiotics from Streptomyces, is because the antibiotics are actually a variety of fungi and bacteria millions of years the process of struggle, resulting in attacks by bacteria, "chemical weapons." It is itself a product of evolution, characterized by the destruction of bacteria, and other life on a small body of mass destruction. Penicillin is able to not only kill the bacteria without damaging human cells due to penicillin Penicillium contained n the synthesis of cell wall of bacteria can occur obstacles, resulting in the death of the bacteria dissolved, and human and animal cells, there is no cell wall. However, when large-scale use of antibiotics by humans, they promoted the evolution of bacteria. Strains of antibiotics were not suited to kill, but to adapt to antibiotics, but the large population of strains.

Penicillin in the last century was the 40's after a large number of applications, humanity has entered the era of antibiotics, infectious disease mortality has declined rapidly, so that the health director of the United States in 1969 that can be declared, and is now "able to close the book on infectious diseases with the time had. " However, the resistance of bacteria gradually surfaced. The most common pathogenic staphylococcus infection as an example. In 1941, looks all aureus can be killed by penicillin, but in 1944, has been decomposed to produce the enzyme penicillin strain emerged. To the last century 90's, 95% of Staphylococcus aureus have a certain degree of resistance to penicillin.

In addition, the human use of other drugs also, such as sulfa drugs to kill bacteria. And similar to penicillin, many bacteria also have had a sulfa drug resistance.

Human errors in the birth of the devil 3

How drug-resistant TB is selected? The medical profession is now generally agreed that drug-resistant TB is created by human error, "the devil." Liang said that the principle of speaking, the emergence of drug-resistant Mycobacterium tuberculosis in two ways, one is a natural mutation, but if at the same time the use of two or more drugs, bacteria through natural mutation of the two drugs have the possibility of drug resistance Great.

The other is the chemical factors of bacterial mutation. If the quality of drugs, or patients with poor compliance, did not require medication, so patients may be the chemical environment of Mycobacterium tuberculosis-induced mutations, resulting in drug-resistant Mycobacterium tuberculosis. Therefore, the majority of drug-resistant TB were trained by human error.

The correct use of medication is early, regular, full course of appropriate drugs, but also combined. The reason why combination therapy is to all of Mycobacterium tuberculosis, "all of a sudden death", not allowing them to evolve drug-resistant variety.

If it is due to human error, in the patient's body to produce a drug-resistant group, then the treatment will be rather difficult. Second-line drugs will be used for a long course of treatment, when patients are more likely to leak medication, a greater variety of training out the possibility of resistance. Now the problem because the prevalence of AIDS has become more complex. Liang said that the AIDS and drug-resistant TB are interdependent and play a role acted as their own immune system, AIDS virus can not be killed, so the bacteria more vulnerable to chemicals in the multi-drug environment easily mutation, a lot of resistance in Mycobacterium tuberculosis AIDS patients from "training" out.

TB breeding because of very slow, usually only a day or so to split the generation, so samples from the extract to determine its resistance need 2-3 months of time for treatment rather passive. Now being studied to speed up the pace, the latest achievement has been to speed up the detection time to 2-3 days.

Once the patient has been "training" a drug-resistant bacteria, he would become a dangerous source of infection, these "no-cure" the disease spread into the air.

4 is also no need to panic too much

Liang said that the TB to human health has become one of the greatest threats. The reason is first of all, TB is difficult to effectively prevent the adoption of personal protection, and the second is the bacteria it can be latent in the human body for many years.

The recent allegation that BCG has been a failure, and this was linked to drug-resistant tuberculosis. Liang said that this is two questions. The role of BCG, there are a lot of controversy, some people believe that it can provide 80% of the protective effect, it was felt that its role is to 0, that is, that are not used. BCG is now generally believed that China is still effective, it can not avoid the infection and incidence of tuberculosis, but can reduce the probability of the occurrence of severe tuberculosis. Our ultimate goal is to develop a highly effective TB vaccine, a particularly effective drug, but now these two have not been done. Therefore, prevention and treatment of TB must be caused by insufficient attention.

Of course, people do not have to panic too much. Liang said that the TB bacteria can survive in the air for about three days, in ten minutes under the sun on the dead. It is also in the infectious droplets in the biggest fall on the ground or if the water on the smaller infectious. Not have to worry about at any time in life will come into contact with drug-resistant Mycobacterium tuberculosis. In general, if not already produced by the body of patients with drug-resistant Mycobacterium tuberculosis direct infection, suffering from TB drug resistance is unlikely. If adequate ventilation, regular exercise, pay attention to the prevention of influenza, the majority of people can be far away from the demons of tuberculosis.

News topics written / our reporter Liu Zheng thanked the topic: Liang (China CDC tuberculosis control director of the Office of Clinical Center)