Acid Fast Bacteria Part 2

Question 1

Often called the MAC or MAI (M avium intracellulare) complex.
Grow optimally at 41°C and produce smooth, soft , nonpigmented colonies.

Answer 1

M avium complex

Question 2

Patients at risk include those with .

Answer 2

cystic fibrosis and pulmonary alveolar proteinosis

Question 3

Pulmonary MAC disease has also been described in middle-aged to elderly women in the absence of chronic lung disease and has been referred to as which this form of the disease is indolent and over time is characterized by nodules in the middle lobes and lingula that progress to cavitation.

Answer 3

Lady Windermere syndrome.

Question 4

Is the most common presentation in young children (< 5 years of age).

Answer 4

Cervical lymphadenitis

Question 5

The major manifestation of M avium complex

Answer 5

unilateral, firm adenopathy; fever is generally absent.

Question 6

MAC organisms routinely are resistant to

Answer 6

first-line anti-tuberculosis drugs

Question 7

Treatment for M avium complex

Answer 7

• With either clarithromycin or azithromycin plus EMB is a preferred initial therapy
• rifabutin (Ansamycin), clofazimine, and fluoroquinolones.

Question 8

A photochromogen that requires complex media for growth at 37°C

Answer 8

M kansasii

Question 9

It can produce pulmonary and systemic disease indistinguishable from tuberculosis, especially in patients with impaired immune responses.

Answer 9

M kansasii

Question 10

M kansasii is sensitive to

Answer 10

RMP, it is treated with the combination of RMP, EMB, and INH with a good clinical response.

Question 11

A scotochromogen occasionally found in water and as a saprophyte in adults with chronic lung disease.

Answer 11

Mycobacterium scrofulaceum

Question 12

Mycobacterium scrofulaceum causes ______ lymphadenitis in children and, rarely, other granulomatous disease.

Answer 12

chronic cervical

Question 13

Surgical excision of involved cervical lymph nodes may be curative, and resistance to antituberculosis drugs is common to treat.

Answer 13

Mycobacterium scrofulaceum

Question 14

These organisms occur in water, grow best at low temperature (31°C), may infect fish, and can produce superficial skin lesions (ulcers, “swimming pool granulomas”) in humans.

Answer 14

Mycobacterium marinum

Mycobacterium ulcerans

Question 15

Treatment for Mycobacterium marinum and Mycobacterium ulcerans

Answer 15

Surgical excision, tetracyclines, RMP, and EMB are sometimes effective

Question 16

These are saprophytes found in soil and water that grow rapidly (3–6 days) in culture and form no pigment. They can produce superficial and systemic disease in humans on rare occasions.

Answer 16

Mycobacterium fortuitum Complex

Question 17

Treatment for Mycobacterium fortuitum Complex

Answer 17

amikacin
doxycycline
cefoxitin
erythromycin
RMP.

Question 18

Both species are capable of causing skin, so tissue, and bone infections after trauma or surgery, which can disseminate in immunocompromised patients.

Answer 18

Mycobacterium chelonae

Mycobacterium abscessus

Question 19

Also frequently recovered from patients with respiratory disease in the United States, especially in south-eastern regions.
The individuals most commonly infected are elderly, white, female nonsmokers

Answer 19

Mycobacterium abscessus

Question 20

Is typically susceptible to tobramycin, clarithromycin, linezolid, and imipenem.

Answer 20

Mycobacterium chelonae

Question 21

Are usually used for treatment of M abscessus, although drug resistance is a major problem with this organism

Answer 21

Clarithromycin, amikacin, and cefoxitin

Question 22

Causes a pulmonary tuberculosis-like disease in adults and lymphadenitis in children.

Answer 22

Mycobacterium malmoense

Question 23

Cause disease in patients with AIDS

Answer 23

Mycobacterium haemophilum and Mycobacterium genavense

Question 24

Current recommendations for prevention of leprosy include a

Answer 24

thorough examination of household contacts and close relatives.

Question 25

Does provide some protection against leprosy especially among household contacts of cases.

Answer 25

BCG

Question 26

Transmission of this is most likely to occur when small children are exposed for prolonged periods to heavy shedders of bacilli.

Answer 26

leprosy

Question 27

Are the most likely infectious material for family contacts.

Answer 27

Nasal secretions

Question 28

The incubation period of M leprea is

Answer 28

2–10 years

Question 29

Are first-line therapy for both tuberculoid and lepromatous leprosy.

Answer 29

Sulfones such as dapsone

RMP and/or clofazimine generally are included in the initial treatment regimens.

Question 30

Scrapings with a scalpel blade from skin or nasal mucosa or from a biopsy of earlobe skin are smeared on a slide and stained by the

Answer 30

Ziehl-Neelsen technique.

Question 31

Nontreponemal serologic tests for syphilis frequently yield ______ results in patients with leprosy

Answer 31

false-positive

Question 32

The skin lesions of this bacteria may occur as pale, anesthetic macular lesions 1–10 cm in diameter; diffuse or discrete erythematous, infiltrated nodules 1–5 cm in diameter; or a diffuse skin infiltration.

Answer 32

M leprea

Question 33

Neurologic disturbances are manifested by nerve infiltration and thickening, with resultant anesthesia, neuritis, paresthesia, trophic ulcers, and bone resorption and shortening of the digits.

Answer 33

M leprea

Question 34

The disease leprosy is divided into two major types:

Answer 34

Lepromatous

Tuberculoid

Question 35

In the lepromatous type, the course is _______, with nodular skin lesions; ________ nerve involvement; abundant acid-fast bacilli in the skin lesions; ______ bacteremia; and a ______ lepromin (extract of lepromatous tissue) skin test result.

Answer 35

• progressive and malignant
• slow, symmetric
• continuous
• negative

Question 36

In the tuberculoid type, the course is ______, with a ______ of macular skin lesions containing few bacilli, ______ nerve involvement of sudden onset, and a _____ lepromin skin test result.

Answer 36

• benign and nonprogressive
• small number
• severe asymmetric
• positive

Question 37

Involvement of this organ is common in leprosy

Answer 37

Eye

Question 38

Involvement of this organ is common in leprosy

Answer 38

Eye

Question 39

Typical acid-fast bacilli—singly, in parallel bundles, or in globular masses—are regularly found in scrapings from skin or mucous membranes (particularly the nasal septum) in patients with lepromatous leprosy.

Answer 39

M leprea

Question 40

When bacilli from human leprosy (ground tissue nasal scrapings) are inoculated into the footpads of mice, _______ with limited multiplication of bacilli.

Answer 40

local granulomatous lesions develop

Question 41

They develop extensive lepromatous leprosy.

Answer 41

Inoculated armadillos

Question 42

M leprae from armadillo or human tissue contains a unique enzyme that is a characteristic of leprosy bacilli.

Answer 42

o-diphenoloxidase