hb'

1. What type of pathogens are antibiotics used for?

Antibiotics are used to treat bacterial infections. They are not effective against viruses, fungi, or other types of pathogens.

2. Why do antibiotics not effect Human cells?

Antibiotics do not affect human cells because they target specific features of bacterial cells. For example, antibiotics may target bacterial cell walls, protein synthesis machinery, or DNA replication processes, which are different from those in human cells.

3. Describe the three ways in which Antibiotics can work

Beta Lactam: These antibiotics, including penicillin, work by inhibiting the synthesis of bacterial cell walls, leading to cell lysis and death.

Macrolides: These antibiotics inhibit bacterial protein synthesis by binding to the bacterial ribosome, preventing the production of essential proteins.

Quinolones: These antibiotics interfere with bacterial DNA replication by inhibiting enzymes like DNA gyrase and topoisomerase, which are crucial for DNA synthesis.

4. describe how antibiotics may be harmful.

Antibiotics can be harmful by disrupting the balance of the gut microbiome, leading to reduced bacterial diversity and dysbiosis. This can result in increased susceptibility to infections, compromised immune function, and other health issues such as allergies, asthma, obesity, and metabolic disorders

5. how our first antibiotic – penicillin, was discovered and by whom.

Penicillin, the first true antibiotic, was discovered by Alexander Fleming in 1928 at St. Mary's Hospital in London. Fleming observed that a mold called Penicillium notatum produced a substance that killed a wide range of harmful bacteria. This discovery led to the development of penicillin as a treatment for bacterial infections

6. Describe the difference between gram positive and gram negative antibiotics.

Gram-positive antibiotics are effective against bacteria that have a thick peptidoglycan layer in their cell walls, which retains the crystal violet stain used in the Gram staining procedure.

Gram-negative antibiotics target bacteria with a thinner peptidoglycan layer but have an outer membrane that can be more resistant to certain antibiotics.

7. Why is there a need to test the bacteria that is causing the infection?

Testing the bacteria causing the infection is essential to determine the most effective antibiotic for treatment. This helps in selecting an antibiotic that the bacteria are sensitive to, ensuring the treatment is effective and reducing the risk of antibiotic resistance.

8. Bactericidal antibiotics to Bacteriostatic antibiotics.

Bactericidal antibiotics: These antibiotics kill bacteria directly. They are often used in situations where the immune system is compromised or the infection is severe.

Bacteriostatic antibiotics: These antibiotics inhibit the growth and reproduction of bacteria, allowing the immune system to eliminate the pathogens. They are used when the immune system can effectively control and eradicate the infection.

9. Broad spectrum versus narrow spectrum antibiotics

Broad spectrum antibiotics: These antibiotics are effective against a wide range of bacteria, both gram-positive and gram-negative. They are useful when the specific bacteria causing the infection are unknown, but they can also disrupt the normal microbiota and lead to resistance.

Narrow spectrum antibiotics: These antibiotics target specific types of bacteria. They are preferred when the causative bacteria are known, as they minimize disruption to the normal microbiota and reduce the risk of developing antibiotic resistance.

10.  Explain the steps in how bacteria may become resistant to a certain antibiotic.

Initial Population: A population of bacteria includes both susceptible and naturally resistant bacteria.

Antibiotic Application: When an antibiotic is used, it kills the susceptible bacteria.

Survival of Resistant Bacteria: The resistant bacteria survive the antibiotic treatment.

Reproduction of Resistant Bacteria: The resistant bacteria reproduce, passing on their resistance genes to their offspring.

Spread of Resistance: Over time, the resistant bacteria become more common, and the antibiotic becomes less effective.

11.  Why is the overuse of antibiotics a contributor to antibiotic resistance?

The overuse of antibiotics contributes to antibiotic resistance because it increases the exposure of bacteria to these drugs. This frequent exposure creates selective pressure, favouring the survival and reproduction of resistant bacteria. As a result, resistant strains become more prevalent, and the effectiveness of antibiotics diminishes.

12.  Find the meaning of “Super bug” ‘Golden Staph” and “MDR bacteria”.

Superbug: A superbug is a strain of bacteria that has become resistant to multiple antibiotics, making it very difficult to treat infections caused by these bacteria.

Golden Staph: a type of bacteria that can cause a range of illnesses. Some strains, like MRSA (Methicillin-resistant Staphylococcus aureus), are resistant to many antibiotics.

MDR Bacteria: MDR stands for Multi-Drug Resistant bacteria. These bacteria are resistant to multiple antibiotics, making infections caused by them particularly challenging to treat

13.  Use the diagram right to summarise the three ways in which a bacteria can change its genes.

Plasmids: Circles of DNA that can move between cells.

Transposons: Small pieces of DNA that can go into and change the overall DNA of cell. These can move from chromosomes (which carry all the genes essential for germ survival) to plasmids and back

Phages: Viruses that attack germs and can carry DNA from germ to germ.

14.  Use the diagram below to explain how a change in a bacteria’s genes can make it resistant to the effect of an antibiotic.

Germs develop new cell processes that avoid using the antibiotic's target.

Germs change or destroy the antibiotics with enzymes, proteins that break down the drug.

Germs restrict access by changing the entryways or limiting the number of entryways.

Germs change the antibiotic's target so the drugs can no longer fit and do its job.

Germs get rid of antibiotics using pumps

15.  Describe why the aseptic technique is necessary.

Aseptic technique is necessary to prevent contamination of cell cultures and reagents from microorganisms in the environment.These steps ensure that experiments are not compromised by unwanted microbial contamination, which is crucial for obtaining reliable and accurate results.

16.  Investigation

Aim

To investigate antibiotic effectiveness against common bacteria strains.

Hypothesis (for each plate say what you think will happen)

For the E. coli plates:

-   Control plate (no antibiotic): Bacterial growth will be observed across the entire plate

-   Experimental plate with antibiotic discs: Zones of inhibition (areas with no bacterial growth) will be observed around the antibiotic discs that E. coli is susceptible to

For the S. epidermidis plates: 

-   Control plate (no antibiotic): Bacterial growth will be observed across the entire plate

-   Experimental plate with antibiotic discs: Zones of inhibition will be observed around the antibiotic discs that S. epidermidis is susceptible to, which may differ from E. coli

In the investigation, how could you make your results:

More accurate

-    Include positive and negative controls to validate experimental conditions.

-    Test a wider range of bacterial species and antibiotic types for broader applicability.

-    Ensure proper incubation time and conditions (temperature, etc.) for optimal bacterial growth

More reliable

-    Repeat the experiment multiple times and calculate averages/statistics across trials.

-    Have multiple groups perform the experiment and compare results.

-    Use standardized bacterial strains and antibiotic discs from reliable sources.

More valid

-    Include positive and negative controls to validate experimental conditions.

-    Test a wider range of bacterial species and antibiotic types for broader applicability.

-    Ensure proper incubation time and conditions (temperature, etc.) for optimal bacterial growth