Mycobacteria

Question 1

How do mycobacteria appear upon staining?

Answer 1

Acid Fast: Acid fast rods

Gram: Gram Positive

Question 2

T/F Mycobacterium are spore forming, aerobic, and slow growing

Answer 2

FALSE

Mycobacterium do NOT form spores, though they are aerobic and slow growing

Question 3

What is the medium used to grow M. tuberculosis and other mycobacterium (except M. leprae)?

Answer 3

Lowenstein Jensen Medium

Question 4

What property of mycobacterium make them resistant to dessication and antibiotic entrance?

Answer 4

Very strong cell wall with mycolic acid coating (“teflon”)

Question 5

T/F: Asians, African Amerians and Hispanics/Latinos all have higher rates of TB than whites

Answer 5

TRUE

Asian: 29x higher

AA/Hispanics/Latinos: 8x higher

Question 6

Primary tuberculosis is acquired via _____

Answer 6

Inhalation of droplet from an active case

Question 7

Initial multiplication of primary TB is in the _____. It spreads through _____ to the _____.

Answer 7

Initial replication is in the alveolar macrophage

Spreads through lymphatic drainage to the hilar lymph nodes

Question 8

An alveolar macrophage that has ingested M. tuberculosis is activated by _____ via interferon gamma.

Answer 8

TH1 cellular immune response

Question 9

What happens when the TH1 cellular immune response successfully activates a macrophage containing MTB? If it is unsuccessful?

Answer 9

Successful activation: Disease arrested

Unsuccessful: Delayed type hypersensitivity injury and progression of disease

Question 10

Reactivation TB typically begins in the _____ of the lung with _____ formation.

Answer 10

Upper lobes with granuloma formation

Question 11

What are some of the hallmarks of TB?

Answer 11

Cough (usually w/mucus), hemoptysis, excessive sweating at night, fatigue, fever, unintentional weight loss (TNF-alpha mediated)

Question 12

A _____ is swelling of a cervical lymph node due to the presence of TB that may be referred to as a “cold abscess.” It is not tender or warm, it is commonly seen in children, and may ulcerate.

Answer 12

Scrofula

Question 13

The _____ test is a subdermal injection of purified MTB proteins. What designates a positive response?

Answer 13

PPD/Tuberculin Skin Test

Presence of a DTH response 2-3 days after injection indicates a positive PPD

Question 14

The _____ test for TB measures levels of IFN-gamma produced by MTB antigen-specific T-cells

Answer 14

Quantiferon Gold test

Question 15

What are the first line drugs used for TB infection?

Answer 15

RIPE Therapy

1) Rifampin
2) Isoniazid
3) Pyrazinomide
4) Ethambutol
5) Streptomycin

Question 16

What are the seven second line MTB treatments?

Answer 16

1) Moxi- or Gatifloxacin
2) Ethionamide
3) Aminosalicylic acid
4) Cycloserine
5) Amikacin + Kanamycin
6) Capreomycin
7) Linezolid

Question 17

The vaccine for TB is the _____, and is a _____ strain of M. bovis

Answer 17

Bacillus Calmette-Guerin (BCG) Vaccine

Live attenuated strain of M. bovis

Question 18

What organism causes Leprosy/Hansen’s Disease?

Answer 18

Mycobacterium leprae

Question 19

M. leprae has a predilection for what parts of the body?

Answer 19

Cooler regions (skin of extremities, mucous membranes, eyes, *peripheral nerves*)

Question 20

A hallmark of M. leprae infection is the involvement of _____

Answer 20

Peripheral nerves

Question 21

Leprosy presents with host dependent, non-healing lesions that have decreased _____

Answer 21

Sensation to touch/heat/pain (parathesis)

Question 22

_____ leprosy is innocuous in terms of inflammatory cells. Acid fast bacteria are typically unable to be identified. Lesions are seen in lighter colored skin, and may be raised or reddish.

Answer 22

Indeterminate leprosy

Question 23

_____ leprosy is the most localized form of leprosy that presents with one or few lesions that are well demarcated,circular, and slightly raised with central clearing. They are insensitive to heat and cold from damage to peripheral nerves.

Answer 23

Tuberculoid leprosy

Question 24

Tuberculoid leprosy is associated with an intense _____ reaction; ____ organisms in the lesions; damage to _____ causing parathesia/anaesthesia

Answer 24

Tuberculoid leprosy:

Intense cell mediated reaction

Few organisms in lesions

Damage to peripheral nerves

Question 25

_____ Leprosy preents with multiple lesions all ove rthe body that are homogenous in color and are more indurated.

Answer 25

Borderline Leprosy

Question 26

_____ leprosy is characterized by unimpeded bacterial growth, with raised lesions all over the body, a lot of macrophages filled with M. leprae, and a “lion-like” face

Question 27

What are the first line Anti-Leprosy drugs?

Answer 27

Rifampin, dapsone, clofazimine

Question 28

What are the second line anti-leprosy drugs?

Answer 28

Minocycline, ofloxacin, clarithromycin

Question 29

What species of mycobacterium is a water-borne contaminate that been seen in cases of Lasik surgery, tattoo ink and wound contamination?

Answer 29

M. chelonae

Question 30

What species of mycobacterium has a similar gross pathology to sporotrichosis and forms “fish tank” granulomas

Answer 30

M. marinum

Question 31

Infection with what species of mycobacterium presents as a steadily progressive, ulcerated lesion over 7 months?

Answer 31

M. ulcerans