1. Antibiotics & Bacterial Resistance

2. Antibiotics
Are natural substances that stops or destroys microorganisms by attacking metabolic pathways in the bacteria
Example
penicillin which works by preventing bacteria from constructing a normal cell wall
Streptomycin works by preventing bacteria from manufacturing proteins

3. The first antibiotic
1928 – discovered by accident Alexander Fleming in
St. Mary's Hospital, London (UK)
He received the Nobel Prize in Medicine in 1945 along
with his two colleagues
He noticed a ring of inhibition of bacterial growth around a contaminant blue-green mould on a Staphylococcus plate culture.

4. The first antibiotic
He then concluded that the mould was releasing a substance that was inhibiting bacterial growth and lysing (killing) the bacteria.
He grew a pure culture of the mould and discovered that it was a Penicillium mould, now known to be Penicillium chrysogenum.

5. ‘Age of Antibiotics’
Since the 1940s researchers have identified more then 2500 naturally occurring antibiotics that can be used to treat infections
However, over the 50 years since, many disease-causing bacteria have become slowly resistant to the antibiotics

6. Antibiotic resistance
Initially when a antibiotic is introduced into a system… it kills off the weaker strains of bacteria
This leaves behind the strong strains
These strong strains have slight variations within their genetic material which allow then to survive the antibiotic

7. These strong bacteria reproduce to pass on their strong fighting ability

9. Antibiotic use in animals
A large percentage of antibiotics produced are used in livestock production in 3 ways…
Therapeutic doses to treat disease
Preventative doses to reduce risk of disease or death during production
Low dose added to feed to promote growth

10. Non-therapeutic use of antibiotics in farm animals is a good or bad thing?
Take 5 minutes and discuss with the person beside you whether it’s a good or bad thing to add antibiotic to livestock feed
Think about… production rates, consumer thoughts, price of meat at the store, health of animals

11. What do you guys think?