Microbial Pathogenicity-32 Flashcards Preview

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Flashcards in Microbial Pathogenicity-32 Deck (21)
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1
Q

Important microbial pathogens examples are

3

A

Virus- H1N1 influenza virus, ss RNA, enveloped

Fungi- Trichophyton spp

Prions- Kuru

2
Q

Important microbial pathogens examples are

3

A

Helminths- Anclyostoma duodenale Hook worm

Protozoa- Plasmodium spp Malaria parasites

Bacteria- Bacillus Anthracis (Gram positive endospore forming rod shaped bacterium).

3
Q

Gram positive bacteria have

A

thick cells walls and consists of peptidoglycan which traps and retains crystal violet stain.

4
Q

Gram negative bacteria have

A

cell walls with 2 layers, a thin peptidoglycan layer and thick outer membrane which contains polysaccharides bonded to lipids.

5
Q

Koch’s postulates are

A

outlines/Guidelines to demonstrate a specific pathogen cause specific disease symptoms

6
Q

Koch’s Postulates outline

4 steps

A
  1. ) Pathogen is present in individual with disease
  2. ) Sample of microorganism from disease host can grow in pure culture
  3. ) Sample of pure culture cause same disease when injected into healthy host.
  4. ) Microorganism is recovered from infected host
7
Q

Key stages of Microbial Pathogenesis are

4

A

Adherence to host cells (Skin or Mucosa),
Invasion of host tissues (Epithelium),
Replication within host tissues (Colonize and growth production of virulence factors),
Disease causing damage to host tissues (pathology)

8
Q

Adherence to host cells

A

Skin or Mucosa

9
Q

Invasion of host tissues

A

Epithelium

10
Q

Replication within host tissues

A

Colonize and growth production of virulence factors

11
Q

Disease causing damage to host tissues

A

pathology

12
Q

List the broad classes of bacterial virulence factors and provide examples for each

Adherance to host cells

A

Adhesions such as Fimbriae-Attachment pilus bind to host cells eg Neisseria Gonorrhoeae.

13
Q

List the broad classes of bacterial virulence factors and provide examples for each

Invasion of host tissues

A

Motility factors,
Flagella move through mucus eg Helicobacter pylori.

Internalin-related proteins (InlB) eg Listeria monocytogenes

14
Q

List the broad classes of bacterial virulence factors and provide examples for each

Replication within host tissues

A

Siderophores (bind iron) Yersinia pestis eg siderophore yersiniabactin solubilizes metal bound to host proteins and transports back to bacteria.

Capsules (resist phagocytosis) eg Streptococcus pneumoniae.

15
Q

List the broad classes of bacterial virulence factors and provide examples for each

Disease causing damage to host tissues (pathology)

A

Toxic virulence factors. Endotoxins cause inflammation Exotoxins can be fatal.

16
Q

Exotoxins are..

3 types

A

produced in living bacteria and released into surrounding medium.

Cytotoxins
Neurotoxins
Enterotoxins

17
Q

Cytotoxins

A

Streptolysin made by bacteria Streptococcus pyrogenes cause complete lysis of RBC (Beta Hemolysis).

18
Q

Neurotoxins

A

Botulinum made by bacteria Clostridium botulinum, cause paralysis

19
Q

Enterotoxins

A

shiga toxin made by bacteria shigella dysenteriae cause severe dysentery.

20
Q

Endotoxins are

A

lipopolysaccharides (LPS) in outer membrane of Gram negative Bacteria and elicit strong immune responses.
Eg Neisseria Gonorrhoeae cause inflamation

21
Q

Effects of Endotoxin lipid A are

A

Fever, Blood clotting, Inflammation and Shock