填空题 Insects entombed in fossilised amber for tens of millions of years have provided the key to creating a new generation of antibiotic drags that could wage war on modem diseases. Scientists have isolated the antibiotics from microbes preserved either inside the intestines of the amber-encased insects or in soil particles trapped with them when they were caught by sticky tree resin up to 130 million years ago. Spores of the microbes have survived an unprecedented period of suspended animation, enabling scientists to revive them in the laboratory.
Research over the past two years has uncovered at least four antibiotics from the microbes and one has been able to kill modern drug-resistant bacteria that can cause potentially deadly diseases in humans. Presentday antibiotics have nearly all been isolated from microorganisms that use them as a form of defence against their predators or competitors. But since the introduction of antibiotics into medicine 50 years ago, an alarming number have become ineffective because many bacteria have developed resistance to the drugs. The antibiotics that were in use millions of years ago may prove more deadly against drug-resistant modern strains of disease-causing bacteria.