Microbiology

Question 1

Type of mechanism of action

Diphtheria toxin, Exotoxin A, and Shiga toxin

Answer 1

Inhibit protein synthesis

Question 2

Diphtheria toxin and pseudomonas aeruginosa method of action

Answer 2

Ribosylation of EF-2 –> decreased protein synthesis

Question 3

Shigella toxin inhibits protein synthesis by what mechanism

Answer 3

Inactivation of 60S ribosome unit

Question 4

Clostridum perfringens causes gas gangrene though what mechanism

Answer 4

Phospholipase C mimetic –> splits host phospholipids –> tissue necrosis

Question 5

Method of action of C. Diff

Answer 5

Actin depolymerization
Psudomembrane formation

Question 6

Shiga toxin (from Shigella spp and Enterohemorrhagic E. Coli is associated with which disease?

Answer 6

Hemolytic uremic syndrome.

Question 7

These 2 spirochetes are too small to see on gram staining

Answer 7

Treponema (syphillis) and Leptospira (infected animal urine in water)

Question 8

BLT

What are the 3 types of spirochetes?

Answer 8

Spirochetes are spiral shaped bacteria which include
1. Borellia
2. Leptospira
3. Treponema

Question 9

What kind of stain is used for Mycobacteria? Why?

Answer 9

Ziehl-Neelsen
Cell wall is too fatty

Question 10

Really Chilly and Cold

Name the 3 intracellular anaerobes

Answer 10

1. Rickettsia
2. Chlamydia
3. Coxiella

Question 11

HeLiCOPters Are Silver

What bacteria/fungi are seen on silver stain?

Answer 11

1. H. Pylori
2. Legionella
3. Coccidiodes
4. Pneumocytis jirovecii
5. Aspergillus fumigatus

Question 12

Certain Bugs Really Try my Patience

What bacteria are seen on Giemsa Stain?

Answer 12

Chlamydia
Borellia
Rickettsia
Trypanosomes
Plasmodium

Question 13

Please SHiNE my SKiS

Which bacteria are encapsulated?

Answer 13

Pseudomonas aeruginosa
Streptococcus pneumoniae
H. Influenzae B
Neisseria meningitis
E. Coli
Salmonella
Klebsiella
Strep agalactiae (Group B)

Question 14

What are the 4 systemic fungi?

Answer 14

Histoplasma
Blastomyces
Coccidioises
Paracoccidioises

Question 15

Demographic location

Histoplasma
Blastomyces
Coccidioises
Paracoccidioises

Answer 15

Histoplasma - Mississipi and Ohio Rivers
Blastomyces - Great lakes, Ohio Valley
Coccidioises - California, southwest
Paracoccidioises - South America

Question 16

Histoplasma spores are typically contracted in which demographic region and from what animal droppings?

Answer 16

Bat and bird droppings in the Mississippi to Ohio rivers

Question 17

Blastomyces yeast look like what on histology staining?

Answer 17

Broad Based Budding

Question 18

Size of these fungi in comparison to RBCs
1. Histoplasma
2. Blastomyces dermatitidis
3. Coccioides and paracoccioides

Answer 18

Histoplasma - much smaller
Blastomyces - about the same
Coccioides and paracoccioides - much larger

Question 19

What are the unique symptoms of Histoplasma capsulatum infection?

Answer 19

Mouth ulcers
Erythema nodosum

Question 20

What are the unique symptoms of Blastomyces dermatitidis infection?

Answer 20

Skin lesion (veruccas)
Osteolytic bone lesions
Hazy chest x-ray

Question 21

What are the unique symptoms of Coccidioises immitus infection?

Answer 21

arthralgias, erythema nodosum, meningitis

Question 22

Coccidioises immitus spores are typically contracted in what demographic region and through what resovoir?

Answer 22

California/southwest america
The spores are found in dust, especially after an earthquake

Question 23

Paracoccioides brasiliensis yeast is compared to what shape on histology?

Answer 23

A Captain’s Wheel

Question 24

What are the unique symptoms of Paracoccioides brasiliensis infection?

Answer 24

Mouth ulcers
Verucca skin lesions (like blastomyces)
Cervical lymphadenopathy

Question 25

What is the treatment for localized fungal infections?

Answer 25

-Azole drugs

Question 26

What is the treatment for disseminated systemic fungal infections?

Answer 26

Amphotericin B

Question 27

Which fungus is responsible for tinea (Pityriasis) versicolor?

Answer 27

Malassezia furfur

Question 28

What is the method of action of malassezia versiolor for causing hyper and hypopigmentation on the chest and back?

Answer 28

Lipid degredation forms acid which damages melanocytes

Question 29

# Italian What does malassezia furfur look like on KOH prep?

Answer 29

Sphagetti and meatballs

Question 30

Where does malassezia furfur usually colonize?

Answer 30

It is part of the normal skin microbiota. It overgrows in the humidity

Question 31

Dermatophytes (fungi) cause what group of skin conditions?

Answer 31

Tinia

Question 32

Tinia cruris is also known as?

Answer 32

Jock itch

Question 33

What is the treatment for tinea infections?

Answer 33

Topical azoles

Question 34

# Turban What is the treatment for onychomyocosis (nails)

Answer 34

Terbinafine

Question 35

# Tin man What is the treatment for resistant tinea infections?

Answer 35

Griseofulvin

Question 36

What does dermatophytes look like on KOH prep?

Answer 36

Branching septate hyphae

Question 37

# Shanked by a rose Sporothrix schenkii is shaped like what in the human body?

Answer 37

A cigar

Question 38

Sporothrix schenckii initially enters the body after being pricked by a thorn. How does it travel once inside?

Answer 38

Ascending via lymhatics

Question 39

What is the treatment of rsporothrix schenckii?

Answer 39

Azole medications Potassium iodide used to be used in the past

Question 40

Sporothrix schenkii is also known as what disease?

Answer 40

Rose gardner's disease

Question 41

What is the function of protein A? Which bacteria uses it?

Answer 41

Bind Fc region of the antibody, preventing opsonization. Staph Aureus

Question 42

# SHiN Which bacteria uses IgA protease? What is the function?

Answer 42

S. pneumoniae H. influenzae Neisseria Cleaves IgA, able to colonize mucous membranes

Question 43

Which bacteria uses Protein M? What is the function?

Answer 43

Protein M prevents phagocytosis. Group A Strep (streptococcus pyrogenes)

Question 44

Which bacteria causes ***toxic shock syndrome*** and ***scalded skin syndrome***

Answer 44

Staph Aureus

Question 45

Which bacteria causes toxic shock Like Syndrome and scarlet fever?

Answer 45

Strep pyogenes

Question 46

# NO StRES What is the novibiocin sensitivity of: Staph epidermidis Staph saprophyticus

Answer 46

Saprophyticus - Resistant Epidermidis - Sensitive

Question 47

# NNot Side effects of aminoglycosides

Answer 47

Neprhotoxicity Neuromuscular blockade Ototoxicity Teratogenicity

Question 48

# GNATS What drugs belong to aminoglycosides

Answer 48

Gentamycin Neomycin Amikacin Tobramycin Streptomycin

Question 49

Symptoms of Lyme Disease

Answer 49

1. Flu like symptoms, target rash 2. Months later - facial palsy 3. Asymmetric arthritis (knee)

Question 50

Treatment of Lyme disease

Answer 50

Doxycycline, ceftriaxone