L26_Intracellular Bacteria Flashcards Preview

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Flashcards in L26_Intracellular Bacteria Deck (13):
1

Are there antibodies present on the inside of cells?

No

2

Classify the following as Obligate or facultative intracellular pathogens: Rickettsial, Cocci, Enterics, Mycobacter, Viruses, Bacilli, Listeria, Chlamydia, Legionella, Fungi

Obligate: Rickettsial, Chlamydia, Viruses
Facultative: All the Rest

3

What is one of the most common virulence factors among intracellular parasites? What are two common functions of the this virulence factor?

Type 3 Secretion Systems. Two common functions are to enhance phagocytosis by the target cell type or alter the endosome so that lysosomes fail to fuse to it.

4

What is a key feature of antibiotics used against intracellular parasites. What is the most common class prescribed. When is this class contraindicative?

To be effective against bacteria that replicate primarily within host cells, antibiotics must cross the human cell membrane easily and remain active or activatable after doing so. Tetracyclines are often the first choice but are contraindicated in pregnancy.

5

What type of foods are typically associated with Listeria Monocytogenes?

Cold stored pre prepared foods: soft cheeses and deli meat

6

Describe Listeria. Monocytogenes life after endocytosis, and its danger to the host?

After endocytosis, it escapes the endosome and uses actin-based motility to spread between cells. It can cause dangerous disease, particularly meningitis, in people who are immunosuppressed, and will complicate pregnancy. immunocompetent host may suffer gastroenteritis but this is usually handled sufficiently by a health immune system.

7

What does Rickettsia Rickettsiae cause? What type of parasite is it and how do humans contract it?

Rocky Mountain Spotted Fever. Rickettsia rickettsiae is an obligate intracellular bacterium that is vectored to humans by ticks.

8

What is the pathogenesis of Rickettsia rickettsiae?

Infects the endothelium of blood vessels, causing leakage and dangerous Rocky Mountain Spotted Fever.

9

What virulence factors does Rickettsia rickettsiae have?

Carries virulence factors for adhesion, cell entry, endosomal escape, and actin-based cell-cell spread.

10

Describe the difference between elementary and Reticulate bodies of chlamydia?

The genus Chlamydia has a very unusual obligate-intracellular replication strategy featuring tiny, infectious, rugged, elementary bodies which “unpack” into larger, delicate reticulate bodies after cell penetration. RB's are active replicators and stain Gram neg. EBs are more difficult for the immune system to eliminate.

11

How does chlamydia enter the cell and replicate?

They carry a T3SS for entry and establishing the intracellular inclusion body within which the reticulate bodies multiply and convert back into elementary bodies.

12

Individuals infected with chlamydia carry a risk for what sequel?

Reactive Arthritis

13

What must you be aware of when treating an individual for STDs and for chlamydia in general?

Genital chlamydia may “hide behind” another STD infection on exam. Reinfection from a still-infected partner is much more common than antibiotic resistance.