1. Define the term antibiotics Antibiotics are a drug used to treat infections caused by bacteria and other microorganisms. Originally, an antibiotic was a substance produced by one microorganism that selectively inhibits the growth of another. Synthetic antibiotics, usually chemically related to natural antibiotics, have since been produced that accomplish comparable tasks 2. a) who was the first scientist to discover antibiotics Alexander Fleming (1928).
b) Briefly describe the circumstances behind this discovery Fleming found that a mould – penicillin, on a discarded culture plate had an antibacterial action to the bacteria staphylococci – a source of serious and possibly fatal human infection. c) What is Howard Florey famous for? Howard Florey was an Australian pharmacologist and pathologist who further studied penicillin and later carried out trials on humans, playing an important role in the extraction of penicillin. 3.
Name four different types of antibiotics – amoxicillin -cefotaxime -vancomycin -teicoplanin 4. Briefly explain how penicillin works Penicillin operates by dissolving the cell wall of bacteria, dispersing its cytoplasm and other cell systems. Molecules of penicillin act as a substrate attachment for the transpeptidase in the cell wall, and when activated prevent peptiodoglycan reactions that strengthen links in the cell wall – this leads inevitably to cytolysis and cell death. 5.
Do they work against all pathogens? Explain Antibiotics are a treatment of an infection caused by bacteria. They target only bacteria – they do not attack other organisms, such as fungi or viruses. This is because antibiotics attack the cell wall in destroying it and fungi’s and viruses do not have cell walls. 6. What are some of the side effects of using antibiotics? The most common side-effects with antibiotics are diarrhoea and nausea, although side effects are not always obvious.
Treatment with broad-spectrum antibiotics may result in fungal infections (such as thrush) as the antibiotics may also destroy all of the body’s good bacteria which assist in controlling overgrowth of micro-organisms. More serious side effects may, but rarely, occur including kidney problems, problems in blood clotting or blood disorders, increased sensitivity to the sun and also deafness. 7. What is meant by the term antibiotic resistance? Resistance can start when bacteria causing an infectious aren’t completely killed off by the antibiotic used.
The bacteria that have survived can develop inherited mutations which can make them resistant to this particular antibiotic or to different types of antibiotic. The resistant bacteria are able to cause an infection that is resistant to treatment with that particular antibiotic. These bacteria can then become difficult to treat. 8. Explain in terms of natural selection how resistance comes about Resistance is a form of natural selection for bacterial (survival and successful reproduction of the organisms that are best suited to their environment).
Microorganisms that have a genetically mutate which enable them to survive antibiotics are able to reproduce and multiply passing on this resistant gene to other microorganisms to the antibacterial strain, thus causing a generation of resistant microorganisms. 9. Assess practices by humans which have contributed to the development of antibiotic resistance -Stopping taking antibiotics too early or not according to the instructions given may increase the risk of antibiotic resistance. Even if the infectious feels to be gone, the full course of antibiotics should be taken.
-Too widely used for common infections not treatable with antibiotics (e. g. flu) -Use in animal feed trying to make them less susceptible to microorganisms thus being able to grow quicker, sell faster and as better quality meat 10. Discuss some of the consequences of antibiotic resistance Diseases thought to have been eradicated have remerged and diseases thought to have been curable have become incurable, e. g. TB has proven to have become more difficult to cure now than previously due to resistance.
Without new methods for attacking them, potentially fatal bacterial infections could pose a serious threat to the world’s population. 11. Propose ways of dealing with the resistance problem in the future -New classes of anti-infective drugs – Virtually no new classes of antibiotics have been discovered in recent years -Diagnostic tests – Prudent prescribing of appropriate antibiotics is best achieved if doctors have access to quick and inexpensive diagnostic tests to identify pathogens and their resistance properties.
-Vaccine development – Infection control through vaccination is an indirect but very powerful and cost-effective way to reduce the need for antibiotics -Surveillance – Epidemiological surveillance of antibiotic resistance in human and animal pathogens is an essential component in the strategy. Antibiotic consumption must be monitored and linked to both resistance data and clinical outcomes.
-A multi-faceted problem – The problem of antibiotic resistance is truly multi-faceted and brings with it wide-ranging socio-economic and political consequences. It addresses many aspects of the social and health economy, such as prescribing behaviour and education of doctors, medical reimbursement, and public expectations. It also reaches beyond human medicine into animal health, farming and food industries, and environmental issues. For the new approach to be successful, this broad range of factors must be taken into account.