Is there really no cure for ＂superbugs＂
Yao Zhenjiang, an associate professor at guangdong pharmaceutical university College of Public Health, recently published a study in the international academic journal Science Report, which showed that his research team collected 320 samples from seven lines of Guangzhou Metro where passengers often touched, and detected that 2.5% of the samples contained "super bacteria" — — Methicillin-resistant Staphylococcus aureus (MRSA). This kind of bacteria has strong resistance to antibiotics, and once infected, it can cause death. For a time, "Guangzhou Metro detected ‘ Super bacteria ’ " The news quickly ignited public opinion.
Guangdong disease control experts explained that superbugs don’t mean to increase the lethality of people, nor will they lead to new diseases, so there is no need to panic too much. But superbugs will make the disease more difficult to cure, and new drugs need to be developed to treat it. However, due to various reasons such as technology and market, there is basically no breakthrough in the research and development of broad-spectrum antibiotics in the past 30 years. On the other hand, the abuse of antibiotics is still serious. Although the National Health and Family Planning Commission issued the "most severe resistance order in history" this year, some studies show that the big users of antibiotics are in animal husbandry.
Faced with the threat of more and more "super bacteria", who is competing with it?
MRSA is the "old man" in the "superbug"
Yao Zhenjiang published this paper in the international academic journal Science Report on October 29th, saying that researchers collected 320 samples on seven lines of Guangzhou Metro (lines 1, 2, 3, 4, 5, 8 and APM) by using cotton test paper method, which mainly came from ticket vending machines, escalators, seats, rings and vertical poles in the subway. After testing, the researchers found that 60.31% of the sampling points contained drug-resistant Staphylococcus, and 8 of them contained "superbugs", namely methicillin-resistant Staphylococcus aureus (MRSA), with a detection rate of 2.5%. This result is the same as the previous detection rate of Japan on a train.
The news that "superbugs" are around has aroused great public concern. What is superbug, and what is the risk of infection for ordinary people? Professor Ye Xiaoguang, deputy director of the Guangdong Infectious Diseases Society and director of the Department of Infectious Diseases of the Second Affiliated Hospital of Guangzhou Medical University, pointed out that the so-called "superbug" is actually not a bacterium, but the name of a class of bacteria. The commonness of this kind of bacteria is that they are very resistant to almost all antibiotics.
Superbacteria is not a new thing. As early as 1987, British researchers isolated the first superbacteria VRE (Vancomycin-resistant Enterococcus), which spread all over the world and is still one of the main pathogens of hospital infection. The first superbug recognized all over the world is MRSA (methicillin-resistant Staphylococcus aureus) detected on this subway. Both MRSA and VRE can cause lung infection and lead to death.
Clinical common members of the "superbacteria" family include methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), pan-drug resistant Acinetobacter baumannii, multi-drug resistant Pseudomonas aeruginosa and so on. In 2009, the appearance of a new metalloenzyme, New Delhi Metallo-Lactamase 1(NDM-1), once made "superbugs" a hot topic of public opinion. Enterobacteriaceae carrying NDM-1 had significant multi-drug resistance, also known as "superbugs".
Professor Ye Xiaoguang said that as time goes on, the list of "superbugs" will get longer and longer. The "war" between humans and superbugs may have just begun. As far as MRSA is concerned, it actually exists widely in many places such as animals and human skin surfaces. In hospitals, this drug-resistant bacteria can be said to be a "frequent visitor". It was found that MRSA accounted for more than 80% of the total number of Staphylococcus aureus in some hospitals, and according to epidemiological statistics, the mortality rate of MRSA caused by lung infection reached about 40%. Therefore, Ye Xiaoguang also pointed out that it is not surprising that MRSA was detected on the subway this time.
In the "superbug" family, MRSA, although senior, can only be regarded as the younger brother when it comes to drug resistance.
Superbacteria are not "incurable"
Professor Ye Xiaoguang introduced that MRSA (methicillin-resistant Staphylococcus aureus) is not strong in independent survival. For ordinary people, * has several lines of defense against bacteria. Although there are risks of infection, the infection rate is actually not high. Even after human infection, it does not mean that there is no medicine to cure, but the traditional antibiotics such as penicillin are not effective, but vancomycin is still effective. What’s more, there are other "killer weapons" for human beings, such as streptomycin and so on, and there are also combined treatment schemes available.
Ye Xiaoguang emphasized that the susceptible population of "super bacteria" are mostly critically ill patients, long-term hospitalized patients, patients who use antibacterial drugs for a long time and patients who receive invasive operation treatment. Take MRSA as an example. Usually, the infection rate in the hospital is relatively high. Patients with heart disease, diabetes and hypertension are hospitalized, and their immunity is low. If this kind of bacteria exists in the hospital environment, hospital-acquired infection may occur. This infection route includes respiratory tract and direct contact. "For this kind of bacterial infection, there are not many antibiotics with targeted effects. Once the drug-resistant gene is produced, it will cause great clinical trouble and it is not easy to find drugs. " However, once the bacterial culture confirms that MRSA is infected, there is still a cure. Professor Ye Xiaoguang said, "MRSA and NDM-1 are not an order of magnitude superbug". "Even if NDM-1 is newly discovered in recent years, most antibiotics are ineffective, but there are still combined treatments."
In an interview with the media, Deng Zide also said that with the advent of antibiotics such as vancomycin, teicoplanin and linezolid, MRSA is no longer a "superbug" in a strict sense.
Professor Ye Xiaoguang has been monitoring the situation of drug-resistant bacteria in the hospital all the year round. He said that according to the observation in the last five years, due to the disinfection in the hospital, the protection of medical staff in place and the popularization of the concept of hand washing, the detection rate of MRSA in the hospital has also declined.
Drug resistance: the disaster caused by antibiotic abuse?
According to a popular science article, the drug resistance of antibiotics is not that * is resistant to antibiotics, but that pathogens in * are resistant, and pathogens will spread. "That’s why drug resistance is a global problem, even if you don’t take antibiotics, it will have something to do with you."
Drug resistance is closely related to antibiotic abuse. According to statistics, the annual per capita sales of antibiotics in China reached 138 grams, 10 times that of the United States. Among hospitalized patients in China, the utilization rate of antibiotics is as high as 70%. A survey by the State Food and Drug Administration shows that the proportion of irrational use of antibiotics in China exceeds 46%; In Canada and the United States, the proportion of overuse of antibiotics is 15% and 30%. In August this year, the National Health and Family Planning Commission issued the Guiding Principles for Clinical Application of Antibacterials (2015 Edition) and the Notice on Further Strengthening the Management of Clinical Application of Antibacterials, which strictly regulated the use of antibacterial drugs in hospitals.
However, residual antibiotics in animal products have become one of the important reasons for the emergence of drug-resistant bacteria. According to a study released by Yingguangguo Research Group of Guangzhou Institute of Geochemistry, China Academy of Sciences, the total amount of antibiotics used in China in 2013 was about 162,000 tons, of which 48% were for human use and the rest were for veterinary use. In 2008, Xiao Yonghong, a professor at the State Key Laboratory of Infectious Diseases Diagnosis and Treatment in the First Hospital of Medical College of Zhejiang University, organized a study that the ratio of antibiotics used for human and veterinary use in China was equivalent to that in the United States, about 3: 7. In April this year, the School of Public Health of Fudan University in Shanghai conducted urine tests on more than 1,000 school children aged 8-11 in Jiangsu, Zhejiang and Shanghai. The results showed that nearly 60% of the children’s urine contained antibiotics. In May 2014, a research report published by East China University of Science and Technology and other institutions said that there were 68 kinds of antibiotics in surface water in China.
"Post-antibiotic era" is approaching
Since the birth of antibiotics for a hundred years, human beings thought that they could destroy bacteria, but they could not escape the drug resistance caused by biological evolution. As the saying goes, "the Tao is one foot high and the devil is one foot high." Professor Ye Xiaoguang said metaphorically that drug resistance between human beings and bacteria is like a race. If you win, you can survive. The emergence of "super bacteria" has also brought the long-lost antibiotic research and development back to public view.
The World Health Organization and the US Centers for Disease Control and Prevention have warned that the "post-antibiotic era" is approaching, and drug-resistant bacteria may detonate the next round of global pandemic. WHO had predicted that there would be no more than five new varieties of antibiotics in the next decade. In fact, in the past 30 years, the research and development of antibiotics has almost stopped, and there is basically no breakthrough in the research and development of broad-spectrum antibiotics.
Professor Ye Xiaoguang believes that on the one hand, R&D does encounter bottlenecks, and after new antibiotics come out, they will encounter drug resistance problems in a short time, which also makes all parties very cautious in clinical application, and there are many constraints in use. "Can you not use it first?" The research and development of antibiotics requires huge funds, and large pharmaceutical companies that have the strength to undertake it must consider the ratio of input to output. Without corresponding returns, R&D naturally does not give force.
Sir Mark Wolpert, Britain’s chief science and technology adviser, also pointed out in a recent interview with Shell.com that it is less than 100 years since alexander fleming discovered the efficacy of penicillin. With the continuous use of antibiotics, pathogens gradually evolved resistance to them. This has become a major global issue. The only way out is to use antibiotics in the most effective way, and not to use them when they should not be used. "We can’t afford to lose this battle. In the first half of the 20th century, many people died of various infections. If we return to that situation, it will be terrible. " It is reported that this year’s "Longitude Award" in Britain will be used to reward new research related to antibiotics.
Under the increasingly severe antibacterial situation, the development and use of new antibiotics has become a global public health problem. In recent years, with the support of some incentive policies, the antibiotic research and development market has shown signs of recovery. In 2014, after leaving the field of antibiotic research and development for 15 years, Roche announced its return to this field, and cooperated with Discuva, a British biotechnology company, to develop a series of new antibiotics to cope with the increasingly serious threat of drug-resistant pathogens. Subsequently, Roche invested hundreds of millions of dollars to acquire related companies and develop new drugs. The antibiotic giant Merck also spent $9.5 billion at the end of 2014 to acquire the antibiotic pharmaceutical company Cubist Pharmaceutical.
Although the research and development of antibiotics has encountered bottlenecks, human beings do not mean to give in easily. Professor Ye Xiaoguang introduced that on the one hand, it is to optimize the combination of existing antibiotic drugs and use drugs accurately, on the other hand, it also changes its thinking to attack bacteria from other angles, such as small molecular polypeptide antibiotics with biological activity induced in organisms, which can effectively avoid drug resistance. In the research, Ye Xiaoguang’s team also found that extracting relevant effective components from plant medicines can greatly improve the activity of antibacterial drugs and reduce drug resistance.