1. USE OF DRUGS AGAINST MICRO-ORGANISMS
ABBOTTS

2. VACCINES
PAGE 27
Is a suspension of dead, weakened or fragmented germs or their toxins that will stimulate the production of antibodies
These antibodies will induce immunity and so give protection against the disease

3. VACCINES HAVE BEEN DEVELOPED FOR:
Polio
Mumps
Measles
Typhoid
Cholera
Tetanus
Influenza
Yellow fever
Hepatitis A and B
Encephalitis
Typhus

4. VACCINATION
Is a process of giving a vaccine to a person to make them immune to a disease

5. HOW DO VACCINES WORK Contain dead or weak germs
Injected, scratched, breathed in or taken orally
Do not cause disease
T lymphocytes produce antibodies [they think they are alive]
Individual becomes immune to the germ
Antibodies stay in the bloodstream
If live germs enter the body they are destroyed straight away

6. Is there a vaccine to prevent TB?
There is a vaccine for TB disease called Bacille Calmette-Gurin (BCG). It is used in some countries to prevent severe forms of TB in children.

7. ANTIBIOTICS TEXTBOOK PAGE 29
Antibiotics are substances that fight infections caused by bacteria
Different antibiotics are developed to treat different infections
Antibiotics cannot fight infections caused by viruses (colds, flu, HIV)

8. What is an antibiotic ?
A substance that kills or halts the growth of a micro-organism (typically a bacterium) – cannot destroy viruses
Usually made by other micro-organisms (fungi, other bacteria)
Examples
Pencillin
Streptomycin
Chloramphenicol

9. Why don’t antibiotics kill us ?
Bacteria and humans share many core processes
But there are some things that are completely different
bacteria have a peptidoglycan cell wall and we don’t
The best (least toxic to us) antibiotics target these “completely different” structures

10. HOW DO ANTIBIOTICS WORK
Bacteria sometimes get past all the body’s defenses because they have reproduced so fast that the immune system cannot deal with the infection
Permanent damage could be caused to the body
Body needs help from the outside
PAGE 29

11. HOW DO ANTIBIOTICS WORK
Antibiotics destroy the bacteria directly
Each antibiotic targets a certain part of the bacterium’s cell:
Cell wall
stop proper wall formation and the bacterial cell bursts
Cell membrane
damages the membrane which changes the permeability
Protein synthesis
Blocks the process and causes death

13. ADVERSE EFFECTS OF ANTIBIOTICS
SIDE EFFECTS
Nausea, diarrhoea, stomach cramps and vaginal yeast infections
ALLERGIES
Shortness of breath, itching, swelling of lips, face, tongue or fainting

14. ADMINISTRATION
Antibiotics are either injected, given orally, or applied to the skin in ointment form.
Many, while potent anti-infective agents, also cause toxic side effects. Some, like penicillin, are highly allergenic and can cause skin rashes, shock, and other manifestations of allergic sensitivity. Others, such as the tetracyclines, cause major changes in the intestinal bacterial population and can result in superinfection by fungi and other microorganisms.

15. ANTIBIOTIC RESISTANCE
Bacteria can become resistant to antibiotics – they are then not affected by the drug
Result is that diseases like tuberculosis are steadily increasing again
In hospitals some bacteria are resistant to all known antibiotics – they are called “super bugs”

16. HOW DO RESISTANT STRAINS DEVELOP?
Bacteria breed quickly
Populations become enormous
Chance mutations occur which produce bacteria which are resistant to antibiotics
Resistant bacteria survive
Multiply to produce a antibiotic resistant population
Caused by overuse of antibiotics

18. How bacteria become resistant

19. WHY RESISTANT POPULATIONS DEVELOP
ADD TO WORKBOOK
Repeated use of antibiotics
Every time a person takes antibiotics, sensitive bacteria are killed, but resistant ones are left to grow and multiply
Incorrect use of antibiotics
Wrong diagnosis – incorrect antibiotic for the bacterium causing the infection
Unnecessary prescriptions eg for viral infections
Improper use of antibiotics by patients – not completing the course
Use of antibiotics as food additives eg in milk to promote growth

20. DANGERS OF ANTIBIOTIC RESISTANCE
ADD TO WORKBOOK
Ilnesses last longer
More visits to the doctor
More expensive and toxic medicines are needed
Death!

21. TO DO
TEXTBOOK PAGE 28
LEARNING ACTIVITY 19
HOW ANTIBIOTICS WORK

22. TYPES OF ANTIBIOTICS Are made from living organisms
SYNTHETIC ANTIBIOTICS
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.
NATURAL ANTIBIOTICS
Are made from living organisms
Process is called biosynthesis
Are secreted by fungi:
Eg Penicillium which grows on fruit
Streptomyces grows in the soil

23. WHY ANTIBIOTICS DON’T KILL VIRUSES
viruses are not living organisms - they have no biological systems to interrupt. viruses invade other cells and subvert the target cells biological functions to replicate more of themselves. if we created an antibiotic which worked against viraly infected cells, we would be creating an antibiotic which worked against our own cells

24. THE END