We say that if a person is down to earth, he is a down-to-earth person. According to this statement, the teachers and students of the Barton Laboratory at the University of Akron in the United States must be a group of extremely “down-to-earth” people, because they can “foot on” many inaccessible “fields” within a year-from the Canyon of New Mexico, USA From the deep Lechugula cave, to the Tepi cave on the Venezuelan plateau, and then to the iron cave deep in the Brazilian jungle, they explored the caves on five continents.
Yes, they are a group of cave explorers! They really can’t do their job without being down-to-earth-as teachers and students, they should wear clean clothes and exchange knowledge in bright and clean classrooms, but in many cases, they are like in the realistic TV show “Survival from the Wild” Like the protagonist, he walks through various dangerous wild environments such as jungles, rivers, and mountains. They are not afraid of hardship or tiredness, and once they embark on the journey, they will stick to the end. Their love for exploring caves is beyond ordinary people, and this love is passed down from their mentor, Professor of Biology, Hazel Barton.
Born in the UK, Patton is a very adventurous female biologist, known as the Laura Crawford of biology-the heroine of the famous action and adventure film “Tomb Raider”. Why do you say that? Because the cave explored by Patton is extremely dangerous! Barton’s teachers and students are picky. Needless to say, human footprints are involved. Even if there are caves that can be easily reached by creatures, they are not their destination. Their goal is often to stay away from the surface or in isolated caves that stretch for dozens or even hundreds of kilometers in the mountains.
So why should they explore these caves?
An isolated microbial home
It turns out that they believed that only in these places can there be many microorganisms that we have never seen before, because in the dark and deep away from the sun, due to lack of photosynthesis, lack of food, and low oxygen content, most organisms basically do not Will choose to survive in those areas.
So how do these microorganisms, mainly bacteria, survive in these places? It turns out that some bacteria are autotrophic bacteria. They can use carbon compounds or sulfur compounds as raw materials to synthesize nutrients needed for life. These autotrophic bacteria act as plants in the general ecosystem. Some bacteria are heterotrophic bacteria, and they feed on these autotrophic bacteria or other heterotrophic bacteria-through predation relationships, bacteria build their own food chain deep in extremely barren caves.
Due to the occlusion of the environment, many bacteria living in the depths of the cave have never left the cave, which means that these bacteria are entirely new species for humans. If people discover 5 new species in the Amazon jungle, biologists will be ecstatic, and this event will also be a big news, but in an isolated cave, maybe you can find dozens or even hundreds of them. A new species of bacteria. And such caves are countless in the world. According to statistics, there are about 1 trillion different kinds of microorganisms on the earth, and the proportion of the number of microorganisms discovered by humans is only one in a million.
Le Chugula Cave, USA
Due to the extreme scarcity of resources in the cave, bacteria are facing fierce and cruel struggle for survival. Bacteria will attack each other and guard against each other, so they have evolved a very advanced “spear” of the bacterial kingdom-antibiotics, and the “shield” of the bacterial kingdom-antibiotic resistance. Bacteria in the cave secrete antibiotics-by definition, antibiotics are produced by various microorganisms (including bacteria, fungi, and actinomycetes) that can kill or inhibit other microorganisms. Correspondingly, in order to keep oneself in the competition for survival, the bacteria in the cave have basically evolved strong antibiotic resistance.
Barton and her students walked into the cave to collect these highly resistant bacteria. In fact, they have a very big mission-to help mankind survive the crisis of antibiotic failure.
Antibiotic failure crisis
Since penicillin, the first antibiotic drug, was put into clinical use in the 1940s, humans have taken antibiotics for nearly 80 years. Antibiotics have strong antibacterial and bactericidal effects. The mechanism of action is mainly to destroy the unique physiological mechanisms of bacteria-including inhibiting the synthesis of bacterial cell walls, destroying bacterial cell membranes, interfering with the synthesis of bacterial proteins, and inhibiting the replication and transcription of bacterial nucleic acids. 5 ways. At present, there are dozens of antibiotics frequently used by humans and animals, but since the 1980s, almost no new antibiotics have been discovered. This has led to the age of use of various antibiotics currently popular on the market, which has basically been more than 30 years. This has caused a terrible consequence-bacteria gradually develop antibiotic resistance.
The emergence of bacterial resistance has forced people to increase the use of antibiotics. The survey shows that compared with 2000, the global use of antibiotics increased by 65% in 2015, and the use of low- and middle-income countries increased by 114%. However, increasing the amount of medicine does not necessarily work-according to reports, in India alone, 58,000 children die from drug-resistant bacterial infections each year. With the enhancement of bacterial resistance, human antibiotics are about to fail. And the emergence of some “super bacteria” in recent years, that is, bacteria that cannot be killed by all the current antibiotic drugs in humans, has caused panic among humans. How to solve the mystery of bacterial resistance is a very urgent task.
People have always thought that the emergence of bacterial resistance is caused by the widespread use of antibiotics. An important result of the exploration of Barton Cave is to prove that this statement is wrong. Barton’s research tells people that bacterial resistance is naturally occurring-Barton collected 93 strains in a cave, and she brought these strains back to the laboratory and tested them with 26 antibiotics. The results showed that 70% of the strains can resist 3 to 4 antibiotics, 3 strains can resist 14 antibiotics, and one strain can resist all 26 antibiotics. It can be seen that these “recluses” who have never been exposed to antibiotics have long developed drug resistance in the competition for survival.
Bacterial resistance is evolved, so what mechanism can promote this evolution of bacteria? Barton said that certain bacteria can produce specific molecules, which can promote the rapid evolution of bacteria into drug-resistant bacteria, and then have the ability to resist antibiotics. If people can figure out what those molecules are (the production of these molecules is related to certain genes in bacteria), they can be blocked and the bacteria cannot evolve. By studying the drug resistance of cave bacteria, Patton’s ultimate goal is to find the mechanism of bacterial evolution. The current situation is that as long as there is a new drug on the market, bacteria will soon become resistant to the drug. So far, people still cannot know how the bacteria evolved into resistant bacteria.
Oroendoga Caves, USA
Barton’s team has made initial progress in the study of cave bacteria. In addition to discovering hundreds of new bacteria, Patton also discovered new drug resistance genes in these isolated bacteria. For example, Patton discovered a super bacterium called “Paenibacillus sp LC231” in Lechuquier Cave, New Mexico, USA. In this bacterium, in addition to the 12 drug resistance genes that are currently known, Patton also discovered 5 new drug resistance genes were introduced. The discovery of new drug resistance genes has made the research direction of bacterial drug resistance more diverse.
Of course, the expression mechanism of bacterial drug resistance genes may require scientists to spend a long time studying. This work is undoubtedly very arduous, but the passionate Barton and her students will continue to struggle until they can solve the bacterial resistance. So far as the medicinal mechanism.