Year 10 MIM - Disease and Bacteria

Scientific Method

• Obvious

• Discussion with results and procedure

• Conclusion

Koch's Postulates

• Disease must be found in the diseased but not in the healthy

• Disease must be isolated and grown

• Cultured microorganism should cause disease in healthy host

• Disease must be isolated and identified as the same to the original agent

Infectious Disease

A condition that impairs body functioning caused by pathogens transmitted from one organism to another

Zoonotic

Refers to diseases that can be transmitted from animals to humans

Religion

Historically used to explain diseases

Agricultural Revolution

• Zoonotic diseases could spread more easily

• Deadly diseases could survive

Pathogenic Organisms vs. Agents

Organisms:

• Bacteria

• Fungi

• Protozoa

• Multicellular parasites

Agents:

• Viruses

• Prions

Germ Theory

Microorganism, known as pathogens or "germs", can cause disease

Incubation Period

The time between infection and symptoms

The duration during which a host can transmit a disease to others

Case Fatality

The proportion of individuals who die after contracting a specific disease

Bare Reproductive Rate (R)

Amount of people exposed who get infected

Emerging Infectious Disease

A new disease, has a major mutation, or major increase in fatalities/cases

Vector Borne Diseases

A disease that can be transferred from human to animal easily

Pathogen

An infectious agent that causes disease

Virulence

The relative ability of a pathogen to cause rapid and severe disease in a host

Transmission Types

• Air

• Food/Water

• Direct contact

• Animals

• Body fluids

Acute vs. Chronic vs. Latent Duration

• Acute comes and goes fast

• Chronic is slower, usually less severe, but stays for much longer

• Latent has no symptoms

Local vs. System Infection

• Local is one part of the body

• System is most of the body

How Agents Kill:

• Destroy cells and tissue

• Invasion and destruction of host cells

• Triggering host's immune system

Coccus vs. Bacilli vs. Spirals

• Coccus are round

• Bacilli are rectangular

• Spirals are shaped as spirals

Spiral types

• Vibrio

• Sprili

• Spirochaete

Deviations of the above:

• Diplo... is two connected bacteria

• Strepto... is a change of bacteria

• Staphylo... is a cluster of bacteria

Diagram of a Bacteria

Peptidoglycan

A mesh-like structure made of sugars and amino acids that forms the cell wall of bacteria

Gram Positive vs. Negative

• Positive have a thick cell wall

• Negative has a thinner wall with an outer membrane

Binary Fusion

The process of a single-celled organism dividing into two identical cells