Antibiotics are one class of antimicrobials. They are relatively harmless to the host, and therefore can be used to treat infections.
The effectiveness of an antibiotic varies with the location of the infection, the ability of the antibiotic to reach the site of infection, and the ability of the pathogen to resist or inactivate the antibiotic. Some antibiotics actually kill the bacteria (bactericidal).
Whereas others merely prevent the bacteria from multiplying (bacteriostatic) so that the host’s immune system can overcome them.
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Community > Symposia > Unpacking …”/>History:
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Penicillin was the first antibiotic discovered in 1929 by Sir Alexander Fleming (1881-1955). The term antibiotics was coined by Selman Waksman in 1942
Sir Alexander Fleming discovered the antibiotic substance lysozyme and isolated the antibiotic penicillin from the fungus Penicillium notatum.
Alexander Fleming had been culturing bacteria on agar plates, one of which was ruined by an accidental fungal contamination. Rather than discarding the contaminated plate, Fleming noticed a clear zone surrounding the colony of mould. Fleming realized that the mould was secreting something that stopped bacterial growth.
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He knew that this substance might have enormous utility to medicine. Although he was unable to purify the compound, he reported it in the scientific literature in 1929- Since the mould was of the genus Penicillium, he named this compound penicillin.
With the increased need for treating wound infections in World War II, resources were poured into investigating and purifying penicillin. Clinical trials were conducted on laboratory animals which showed positive results without any harm to animals.
Subsequently, new antibiotics were rapidly discovered and came into widespread use.
The discovery of antibiotics, along with anesthesia and the adoption of hygienic practices by physicians (for example, washing hands and using sterilized instruments) revolutionized medicine.
Production of Antibiotics:
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The importance of antibiotics to medicine has led to much research into discovering and producing them. The process of production usually involves screening of wide ranges of microorganisms, testing and modification.
i. Penicillium notatum was the first mould from which penicillin was obtained. Commercially, penicillin is being produced from Penicillium chrysogenum as well as synthetically.
ii. Streptomycin is one of the most widely used antibiotic obtained from a bacterium Streptomyces.
iii. Chlorotetracycline is produced from Streptomyces auriefaciens.
iv. Chloamphenicol is produced from Streptomyces venezuelas.
Uses of Antibiotics:
Antibiotics are used
i. In medicine to fight diseases.
ii. As food preservative to preserve meat and fish.
iii. In treating animal feed to prevent internal infections.