W1 Intro to mycobacteriology

Question 1

Most likely to cause TB

Answer 1

M. tuberculosis (MTB)

Question 2

Blastoconidia

Answer 2

Buds

Question 3

Pseudohyphae

Answer 3

A chain of blastodonidia

Question 4

Molds

Answer 4

multi-nucleated, filamentous fungi composed of hyphae

Obligate aerobes

Question 5

Hypha

Answer 5

Consists of one or more cells surrounded by a tubular cell wall.

Question 6

Aseptate hyphae

Answer 6

hyphae are not partitioned by septa.

Question 7

anamorph

Answer 7

Asexual state

Question 8

Sporulation

Answer 8

Sexual

Question 9

Yeast reproduction

Answer 9

is by budding

Question 10

Teleomorph

Answer 10

Sexual state

Question 11

Polyenes

Answer 11

Bind to ergosterol, disrupting osmotic integrity of membrane.
Amphotericin B
Nystatin

Question 12

Azoles

Answer 12

Inhibit P450 (enzyme 14alphademethylase)
Itraconazole
Voriconazole
Posaconazole

Question 13

Echinocandins

Answer 13

inhibit 1>3 beta D-glucan synthase, blocking cell wall synthesis.
Anidulafungin
caspofungin
micafungin

Question 14

Flucytosine

Answer 14

Selectively converted by fungi to active metabolites and inhibits fungal RNA and DNA synthesis

Question 15

Yeasts

Answer 15

Single, creamy-mucoid, facultative anaerobes.

Question 16

Germ tubes

Answer 16

true hyphae

long branching filaments lacking complete septa form.

Question 17

What is the major structural polymer in fungal cell walls

Answer 17

Chitin

Question 18

Molds reproduce by producing

Answer 18

Conidia or spores

Question 19

What produces asexual reproductive spores

Answer 19

Aerial mycelium

Question 20

Vegetative mycelium

Answer 20

anchors mold and absorbs nutrients.

Question 21

Dimorphic/endemic

Answer 21

Coccidiodes immitis/posadasii; AZ gold miner

Lactophenol cotton blue

Question 22

Opportunistic

Answer 22

Candida spp

Rhizopus spp

Question 23

Cutaneous

Answer 23

Malassezia furfur: seborrheic dermatitis, folliculitis, tinea versicolor,

Question 24

Classic diagnostic approaches

Answer 24

Direct microscopy: 10% KOH (dissolves keratinized particles and helps emulsify solid) and calcoflour white (binds to cellulose and chitin). Fast and cheap but insensitive
Culture; gold standard for sterile body site but delayed results and lack of sensitivity and specificity.
Histopathology; gold standard of invasive disease, but difficult to obtain and not species specific.

Question 25

Novel diagnostic approaches

Answer 25

Serum biomarkers; cell wall markers; Galactomanan, D glucan.
Direct detection; nucleic acid amplification tests;
PCR/sequencing
In situ hybridization

Question 26

Tuberculous Mycobacteria

Answer 26

M. tuberculosis
M. africanum
M. bovis

Question 27

Special Growers

Answer 27

M. leprae

Question 28

TB vaccine

Answer 28

M. Bobis Bacille Calmette-Guerin (BCG)

Question 29

Ghon complex

Answer 29

Characteristic gross appearance with primary TB.

Question 30

Latent TB infection

Answer 30

LTBI

People who are infected but not sick, do not have symptoms and cannot spread TB

Question 31

Mantoux tuberculin skin test

Answer 31

TST or PPD

Read 48-72hrs

Question 32

Nucleic Acid Amplification Test

Answer 32

NAAT
can detect as little as 10 bacilli per sample.
Results 24-48hrs

Question 33

Rapid growers

Answer 33

skin and soft tissue and lung infections