1. Types of Invaders
The pathogens

2. Types of Invaders
Antigens
Microorganisms
Viruses
Bacteria
Fungi

3. Viruses Not considered “living”
They have no cytoplasm or organelles and therefore no cellular metabolism
Needs a living host cell to survive
Will take over host cell to replicate by inserting its DNA/RNA into host’s - they do not reproduce
They can hide host cell beneath cell membrane, body will recognize cell as “self”

4. Viruses can mutate and evolve because they are made up of DNA/RNA
They can only get inside of cells that they have same or similar proteins on surface (capsid) to match “self cell” by stealing pieces from previous hosts. This is why we have human viruses, dog viruses, bird viruses, etc. And why some viruses affect only certain types of cells (nerve cells, skin cells, etc.)
Viral infections cannot be treated with antibiotics but some can treated with anti-viral medication (which acts to slow replication of Viral DNA/RNA) Some can be prevented with vaccines

5. Viruses Rhinovirus-Common Cold- over 200 strains
Varicella - Chicken Pox – rarely fatal
Variola – Smallpox – often fatal – but now eliminated thanks to vaccinations!
Influenza – MANY different strains (Three main genera Influenza A, B, C)
Human Papillomavirus – HPV – can lead to warts, cervical cancer, and some other genital cancers
Rotavirus – leading cause of diarrhea among infants and young children

6. Smallpox
Chicken Pox

7. Viruses Mumps – swelling of salivary glands, and testicular swelling
Measles – begins as upper respiratory infection and later skin rash- can lead to diarrhea, pneumonia, encephalitis, and eye infections
Rubella – rash, swollen glands
Poliomyelitis – usually asymptomatic, sometimes flu-like symptoms, in less than 1% of polio cases, virus enters the CNS, destroying motor neurons, leading to muscle weakness and paralysis; highly contagious
Rabies – causes encephalitis; violent movements, fear of water, can be fatal
HIV-

8. MMR Vaccination protects against all three!
Measles
Mumps
Rubella
MMR Vaccination protects against all three!

10. Vaccination
Administration of antigenic material to produce immunity to a disease
Can be live but weakened, dead, or inactivated form of pathogen (virus or bacteria)
Pathogens are grown in culture and killed/weakened, but surface proteins are intact enough to be recognized
When injected, immune system will evoke a response

11. Bacteria Are considered a “living” prokaryotic cell
Does not need a living host cell to survive
Most (99%) are good (beneficial) few are harmful (pathogenic)
Beneficial bacteria help us with digestion, releasing vitamins, eliminating body toxins, preventing fungal growth

12. Bacteria
Harmful (pathogenic) bacterial infections can be treated with antibiotics
Some can live harmlessly, but develop into an infection if immune system has had its resistance lowered (ex: AIDS)
A few infections can be prevented with vaccines

13. Pathogenic Bacteria Tuberculosis – affects lungs, difficult to treat
Streptococcus – affects throat (pharynx, larynx, tonsils)
Botulism – weakens muscles, prevents breathing
Bubonic Plague – spread by fleas that live on rats; inflames and damages lymph nodes, can kill a human in 4 days
Cholera – affects small intestine, causes diarrhea, vomiting, and rapid dehydration

15. Pathogenic Bacteria
Salmonella – can cause typhoid fever and food poisoning
Escherichia Coli – aka E.Coli – some strains are beneficial, but the pathogens cause lower digestive issues (food poisoning) or UTIs
Syphilis – STD that causes lesions; if left untreated, it can cause issues with the heart and brain
Impetigo – skin infection

16. Pathogenic Bacteria Diphtheria – causes upper respiratory issues
Pertussis – whooping cough
Tetanus – causes muscle spasms
These last three can be quite harmful (even deadly) that is why we receive the DPT vaccination

17. Antibiotics
A substance or compound that kills or inhibits growth of bacteria
Can either be made synthetically from chemicals or produced by fermenting different fungus molds
Unfortunately, bacteria can mutate to become resistant to antibiotics
EX: penicillin, amoxicillin, tetracycline, sulfa drugs, cefzil

18. Fungus Are considered a “living” eukaryotic cell
Includes molds and yeasts
Some are beneficial, such as fungi used to make antibiotics (penicillin) or baker’s yeast
Infections can spread quickly and easily!

19. Pathogenic Fungi
Candida – Yeast Infection, can be in the mouth (candidiasis)
Tinea Pedis – Athlete’s Foot
Tinea Cruris – Jock Itch
Tinea Unguium – Nail Fungus