General Microbial Pathogenesis

Question 1

What are dermatophytes

Answer 1

• fungi

- can cause superficial infections of intact stratum corneum, hair, and nails

Question 2

What are lactobacilli?

Answer 2

• vaginal bacteria

- ferment glucose to lactic acid, producing a low pH environment that will suppress growth of pathogens

Question 3

What is vertical transmission?

Answer 3

-transmission of infectious agents from mother to fetus

Question 4

S aureus secretes _________ which, degrades the extracellular matrix between host cells

Answer 4

hyaluronidase

Question 5

Certain viruses such as rabies and poliovirus spread to the ___________ by infecting _________ and then traveling intracellularly along axons.

Answer 5

central nervous system

peripheral nerves

Question 6

The most common and efficient mode of microbial dissemination is through the ___________.

Answer 6

bloodstream

Question 7

What is the microorganism that can cross the barrier of unbroken skin?

Answer 7

• schistosoma

- releases enzymes that dissolve adhesive proteins that hold keratinocytes together

Question 8

Influenza viruses have envelope proteins called _________that bind to _______ on the surface of epithelial cells in the respiratory tract.

Answer 8

hemagglutinins

sialic acid

Question 9

_________ infection during the first trimester can lead to heart malformations, mental retardation, cataracts, or deafness while ______infection during the third trimester has little effect

Answer 9

Rubella

rubella

Question 10

What is the dominant inflammatory reaction to viruses, bacteria, mycobacteria, fungi, protozoa, and parasites? (assume normal host immune system)

Answer 10

Virus = lymphocytic

Bacteria = granulocytic

Mycobacteria = granulomatous

Fungi = granulomatous

Protozoan = Lymphocytic

Parasite = Eosinophilic

Question 11

What makes RNA viruses so hard to fight off and/or make vaccines for?

Answer 11

-They are hypermutatable

Question 12

What are the ways in which viruses produce disease?

Answer 12

• Direct cytopathic effects: cells fill with virus
• Anti-viral immune reactions
• Transformation of host cell to neoplasm

Question 13

Where do DNA and RNA viruses tend to replicate?

Answer 13

DNA = in nucleus

RNA = in cytoplasm

Question 14

What is an emerging infection?

Answer 14

-a movement of organisms from one usually isolated ecosystem to a new ecosystem

Question 15

What are the usual targets of antibiotics?

Answer 15

• Cell Wall
• Prokaryotic polymerase
• Transcription & translation (prokaryotic ribosomes)

Question 16

What color do gram positive & negative bacteria stain?

Answer 16

• Gram positive = dark blue

- Gram positive = red

Question 17

What are cocci?

Answer 17

Round bacteria in pairs or clusters

Question 18

What re bacilli?

Answer 18

Rod-like bacteria

Question 19

What are Spirochetes?

Answer 19

-cork-screw like bacteria

Question 20

What kind of self-reactive antibodies can result from a Streptococcal infection?

Answer 20

• myocarditis
• Valvular heart disease
• Glomerulonephritis

Question 21

Are mycobacteria gram positive or negative?

Answer 21

Weakly Gram positive

**we rely on Acid-fast bacteria (AFB) stain for mycobacteria

Question 22

What are yeast vs hyphae morphology in fungi?

Answer 22

• yeast = round, budding, and usually much larger than bacteria (predominate at higher temps)
• Hyphae = elongaded structures, filamentous, and often branching (predominate at lower temps)

Question 23

What do fungi look like in GMS stain?

Answer 23

• fungi are black

- background tissue is Green

Question 24

What is a white fungal infection of the tongue and/or pharynx called?

Answer 24

• oral thrush

* caused by Candida

Question 25

What special immune cells eat large deep fungi?

Answer 25

-multinucleated giant cells

**granulomatous inflammation!

Question 26

What is Toxoplasmosis?

Answer 26

-a protozoan that may infect organs in immunocompromised

Question 27

What are Metazoans?

Answer 27

• multicellular eukaryotic organisms

- worms, surface parasites. shisto