General Microbiology - Lecture 8 (Chapter 35)

Pathogenicity and Infection

What is pathogenicity?

The ability of a microorganism to cause disease in a host.

What types of features reflect a microorganism's pathogenicity?

1. Genetic

2. Biochemical

3. Structural

What actions must the features enable a microorganism to do?

1. Enter the host

2. Evade defense

3. Produce harmful effects

Which shows pathogenicity?

The ability to cause disease even at very low infectious doses.

Mycobacterium tuberculosis

Ability to cause tuberculosis (bệnh lao) because it can enter the lungs, survive inside macrophages, resist immunity, and produce granuloma-forming inflammation (viêm tạo u hạt).

What is virulence?

The degree or intensity of of pathogenicity of a microorganism, reflecting how severe a disease can be.

What is infection?

The process in which a microorganism enters, establishes itself, and begins to multiply within a host.

What is infectious disease?

Occurs when an infection leads to damage or dysfunction in host tissues, resulting in observeable clinical symptoms.

How to boost our immune system?

How many steps in the process of infection?

Most pathogens follow 6 essential steps.

First step in the process of infection?

Enter into the host

Ways pathogens can go into the host

Specific portals such as

Second step of the process of infection?

Adherence to host tissues

How can pathogens adhere to the host?

Using microbial adherins such as:

1. Pili

2. Frimbriae

3. Surface protein - binds to

Third step in the process of infection?

Colonization and Invasion

What is colonization?

When will colonization consider successful?

The pathogens

What is invasion?

Fourth step in the process of infection?

Evading host immune defenses

Key immune evasion strategies? (5)

1. Capsule (Anti-phagocytosis)

2. Antigenic variation

3. Coagulase, IgA protease

4. Biofilm formation

5. Surviving inside macrophages

Fifth step in the process of infection?

Causing damage to host tissues

Sixth step in the process of infection?

Exit and transmission

Which characteristic of virus help it spread quickly?

What is adhesion factors?

What is the function of the adhesins?

What is invasion factors?

Some types of invasion factors?

What is the function of the invasion factors?

What is exotoxins?

Which bacteria secretes exotoxins?

Some types of toxins?

What is the function of the exotoxins?

What is endotoxins?

Which bacteria secretes endotoxins?

What do endotoxins cause?

Compare exotoxins can endotoxins (2)

Some factors influence the susceptibility

What can

How can normal microbiota protect the host?

What is ID₅₀?

What is LD₅₀?

What is pathogenicity island?

What is acute infection?

What is chronic infection?

Some chronic diseases caused by bacteria?

Some chronic diseases caused by virus?

Acute/chronic disease compare

What is localized infection?

What is systemic infection?

What is primary infection?

What is secondary infection?

What is opportunistic infection?

What is associated with opportunistic infection?

Opportunistic infection is?

Secondary infection

How can the immune defense protect the host?

How do macrophage engulf bacteria?

Cách hệ miễn dịch màu đỏ