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Wednesday 31 August 2011

Antibiotics

By 1000 BC the Chinese had recognized the antibiotic effect of certain fermented products. For instance they used moldy soybean curds to treat boils and similar skin infections. Around the same time the Central American Indians were treating infected wounds with fungi.

The discovery of the first element that had the power of dissolving bacteria was an accident. In 1928, while working on influenza virus, Scottish research scientist Alexander Fleming observed that mold had developed accidentally on a glass plate he had left in the sink and that the mold had created a bacteria-free circle around itself. He was inspired to further experiment and he found that a mold culture prevented growth of staphylococci, even when diluted 800 times. He named the active substance penicillin.


Fleming's initial work was reported in 1929 in the British Journal of Experimental Pathology, but it would remain in relative obscurity for a decade.

Though Alexander Fleming discovered penicillin, he never tried to make an antibiotic out of it. It was not until a decade later that a man named Howard Florey found Fleming's little-known paper and realized the mold's potential.

World War II brought penicillin to the fore when it saved the lives of countless soldiers who would have died from their wounds in previous wars.

In a 1945 interview with The New York Times, Alexander Fleming warned that misuse of penicillin could result in selection for resistant bacteria. True to this prediction, resistance began to emerge within ten years.

Fleming never made any money from his discovery. He had no wish to do so.

Albert Schatz, a graduate student, first isolated Streptomycin, a bacterial antibiotic produced by the soil actinomycete. in the laboratory of Dr. Selman Abraham Waksman at Rutgers University, New Jersey on October 19, 1943. The antibiotic was the first effective treatment which could be used against tuberculosis. Previously there had been no effective drug for this major killing disease, but by its use tuberculosis was largely eradicated in developed countries by the 1970s.

Waksman and two associates testing Streptomycin

Dr. Waksman and his laboratory staff discovered several antibiotics, including actinomycin, clavacin, streptothricin, streptomycin, grisein, neomycin, fradicin, candicidin, and candidin. It was Waksman who was the first to apply the term "antibiotic".

Around one in 16 people in Britain are prescribed antibiotics each year.

Over 80% of antibiotics used in the United States are used on farm animals.

Bacteria have the ability to develop resistance following repeated doses of antibiotics and since the turn of the century it has become noticeable that bacterial infections are showing increasing resistance to the drugs.

One example is a bacteria that causes pneumonia in the elderly and ear infections in children. The failing success rate of antibiotics for treating this is resulting in the recommendation of the wider use of vaccines to protect young children and the elderly from catching the disease. In another instance a research program discovered that the bacteria that commonly causes urinary tract infections were resistant in nearly one third of the cases to antibiotic treatments. The consequence of this is that there is constant pressure for more advanced antibiotics to be developed to overcome these increasingly resistant infections.

Poster from the US Centers for Disease Control and Prevention "Get Smart" campaign

No new families of antibiotics had been developed since 1987. This was until 2015 when it was announced a new super antibiotic capable of wiping out everything from MRSA to TB had been found lurking in soil. The new drug, teixobactin, was discovered after American, British and German scientists went back to basics and studied bacteria from a grassy field in Maine.

Some leaf cutter ants grow antibiotics on their backs so that when their nests get infected with microbes they roll on it to kill bacteria.  The discovery has applications regarding the search for new antibiotics that can be used in humans.

Phages (a group of viruses) were supposed to be studied as antibacterial agents in human medicine, but were cut short by the discovery of penicillin shortly after. With today's increasingly drug-resistant bacteria, phages are being considered once again.

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