10.2.1
Antibiotics
Antibiotics
Antibiotics
Antibiotics, such as penicillin, are drugs developed to cure infections caused by bacteria. Some antibiotics work by destroying the cell wall of the bacteria so that they can't replicate.


Antibiotics in the mid-20th century
Antibiotics in the mid-20th century
- Penicillin was discovered in 1928 by Alexander Fleming. This finding was amongst the most significant scientific achievements in recent history.
- Following Fleming's discovery, penicillin became widely tested and developed by drug companies.
- Once penicillin had proven itself as an incredibly powerful drug, the race was on to create many more antibiotic variations.


Antibiotics don't affect viruses
Antibiotics don't affect viruses
- Antibiotics do NOT destroy viruses because viruses stay inside host cells and are not living cells.
- Antibiotics kill bacteria by specifically targeting bacterial structures & processes.
- For example, penicillin prevents bacteria from building their cell wall. This can cause the cell to burst.


Antibiotics are specific
Antibiotics are specific
- Specific antibiotics are prescribed by medical doctors for specific diseases.
- The use of antibiotics has greatly reduced the number of deaths from infectious bacterial diseases.
Antibiotic Resistance
Antibiotic Resistance
Some strains of bacteria are resistant to certain antibiotics. This means that these antibiotics cannot kill them.


Becoming resistant
Becoming resistant
- Within a population of bacteria, some will have random mutations (random change in DNA).
- The mutated bacteria are resistant to antibiotics and so they are able to survive, whilst the non-resistant bacteria die.
- The resistant bacteria can reproduce rapidly because their competition (the non-resistant bacteria) has been destroyed by the antibiotic.
- When the resistant bacteria reproduce, they produce genetically-identical copies. These copies will all be resistant to the antibiotics.
- This is an example of natural selection.


MRSA
MRSA
- MRSA stands for methicillin-resistant Staphylococcus aureus.
- MRSA is often called a “superbug” because it is resistant to many antibiotics.
- The people most commonly affected by MRSA are hospital patients.


Clostridium difficile
Clostridium difficile
- Symptoms of C. difficile infections are largely centred around bowel irritation.
- Recent courses of broad-spectrum antibiotics will increase someone's risk of being affected by this bacterium.
- In 2005, a strain developed that was expressing resistance to several antibiotics. This led to several serious outbreaks across the US.


How to stop antibiotic resistance?
How to stop antibiotic resistance?
- To help prevent strains of resistant bacteria from developing:
- Doctors should only prescribe antibiotics if they are needed and not for minor infections or viral infections.
- Patients should complete their course of antibiotics to ensure all bacteria are killed.
1Cell Structure
1.1Cell Structure
1.1.1Studying Cells - Microscopes
1.1.2Introduction to Eukaryotic & Prokaryotic Cells
1.1.3Ultrastructure of Eukaryotic Cells
1.1.4Ultrastructure of Eukaryotic Cells 2
1.1.5Ultrastructure of Eukaryotic Cells 3
1.1.6Prokaryotic Cells
1.1.7Viruses
1.1.8End of Topic Test - Cell Structure
1.1.9Exam-Style Question - Microscopes
1.1.10A-A* (AO2/3) - Cell Structure
2Biological Molecules
2.1Testing for Biological Modules
2.2Carbohydrates & Lipids
2.3Proteins
3Enzymes
4Cell Membranes & Transport
4.1Biological Membranes
5The Mitotic Cell Cycle
6Nucleic Acids & Protein Synthesis
6.1Nucleic Acids
7Transport in Plants
8Transport in Mammals
8.1Circulatory System
8.2Transport of Oxygen & Carbon Dioxide
9Gas Exchange
9.1Gas Exchange System
10Infectious Diseases
10.1Infectious Diseases
10.2Antibiotics
11Immunity
12Energy & Respiration (A2 Only)
13Photosynthesis (A2 Only)
14Homeostasis (A2 Only)
14.1Homeostasis
14.2The Kidney
14.3Cell Signalling
14.4Blood Glucose Concentration
14.5Homeostasis in Plants
15Control & Coordination (A2 Only)
15.1Control & Coordination in Mammals
15.1.1Neurones
15.1.2Receptors
15.1.3Taste
15.1.4Reflexes
15.1.5Action Potentials
15.1.6Saltatory Conduction
15.1.7Synapses
15.1.8Cholinergic Synnapses
15.1.9Neuromuscular Junction
15.1.10Skeletal Muscle
15.1.11Sliding Filament Theory Contraction
15.1.12Sliding Filament Theory Contraction 2
15.1.13Menstruation
15.1.14Contraceptive Pill
15.2Control & Co-Ordination in Plants
16Inherited Change (A2 Only)
16.1Passage of Information to Offspring
16.2Genes & Phenotype
17Selection & Evolution (A2 Only)
17.2Natural & Artificial Selection
18Classification & Conservation (A2 Only)
18.1Biodiversity
18.2Classification
19Genetic Technology (A2 Only)
19.1Manipulating Genomes
19.2Genetic Technology Applied to Medicine
19.3Genetically Modified Organisms in Agriculture
Jump to other topics
1Cell Structure
1.1Cell Structure
1.1.1Studying Cells - Microscopes
1.1.2Introduction to Eukaryotic & Prokaryotic Cells
1.1.3Ultrastructure of Eukaryotic Cells
1.1.4Ultrastructure of Eukaryotic Cells 2
1.1.5Ultrastructure of Eukaryotic Cells 3
1.1.6Prokaryotic Cells
1.1.7Viruses
1.1.8End of Topic Test - Cell Structure
1.1.9Exam-Style Question - Microscopes
1.1.10A-A* (AO2/3) - Cell Structure
2Biological Molecules
2.1Testing for Biological Modules
2.2Carbohydrates & Lipids
2.3Proteins
3Enzymes
4Cell Membranes & Transport
4.1Biological Membranes
5The Mitotic Cell Cycle
6Nucleic Acids & Protein Synthesis
6.1Nucleic Acids
7Transport in Plants
8Transport in Mammals
8.1Circulatory System
8.2Transport of Oxygen & Carbon Dioxide
9Gas Exchange
9.1Gas Exchange System
10Infectious Diseases
10.1Infectious Diseases
10.2Antibiotics
11Immunity
12Energy & Respiration (A2 Only)
13Photosynthesis (A2 Only)
14Homeostasis (A2 Only)
14.1Homeostasis
14.2The Kidney
14.3Cell Signalling
14.4Blood Glucose Concentration
14.5Homeostasis in Plants
15Control & Coordination (A2 Only)
15.1Control & Coordination in Mammals
15.1.1Neurones
15.1.2Receptors
15.1.3Taste
15.1.4Reflexes
15.1.5Action Potentials
15.1.6Saltatory Conduction
15.1.7Synapses
15.1.8Cholinergic Synnapses
15.1.9Neuromuscular Junction
15.1.10Skeletal Muscle
15.1.11Sliding Filament Theory Contraction
15.1.12Sliding Filament Theory Contraction 2
15.1.13Menstruation
15.1.14Contraceptive Pill
15.2Control & Co-Ordination in Plants
16Inherited Change (A2 Only)
16.1Passage of Information to Offspring
16.2Genes & Phenotype
17Selection & Evolution (A2 Only)
17.2Natural & Artificial Selection
18Classification & Conservation (A2 Only)
18.1Biodiversity
18.2Classification
19Genetic Technology (A2 Only)
19.1Manipulating Genomes
19.2Genetic Technology Applied to Medicine
19.3Genetically Modified Organisms in Agriculture
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