MYCOBACTERIUM OTHER THAN TUBERCULOSIS

Question 1

• It is medically important to characterize and separate M. tuberculosis from all other species of mycobacteria.

Answer 1

RUNYON CLASSIFICATION

Question 2

Common mycobacteria

Answer 2

M. tuberculosis
M. leprae
M. avium complex
M. bovis

Question 3

________on Middlebrook Agar
Mycobacteria pathogenic for humans can be differentiated
(Runyon Groups)

Answer 3

Photochromogenic M. kansasii

Question 4

Mycobacteria pathogenic for humans can be differentiated
(Runyon Groups) by:

Answer 4

speed of growth (all are slower than most other pathogens) and by

• production of chromogenic pigments (in light, in dark, or none)

Question 5

New Species Identified: Two new species,(2), were identified between January 2020 and October 2022.

These species were isolated from human sputum samples and are associated with respiratory diseases

Answer 5

Mycobacterium vicinigordonae and Mycobacterium senriense

Question 6

Breakthrough Antibiotic: Researchers at the National University of Singapore have developed a novel antibiotic named______.

This antibiotic shows promise against hard-to-treat mycobacterial lung infections, particularly those caused by Mycobacterium abscessus.

It disrupts bacterial defenses and exhibits a low frequency of resistance, making it a potentially safer and more effective treatment

Answer 6

COE-PNH2

Question 7

Opportunistic Mycobacterial Disease

Lymphadenopathy

AIDS related

Answer 7

M. avium complex

M. avium complex

Question 8

• similar to M. tuberculosis
• the primary cause of tuberculosis in cattle
• Humans can acquire it from cattle by drinking______ if the cow has not been vaccinated

Answer 8

Mycobacterium bovis

unpasteurized milk

Question 9

• A unique identifying characteristic - it is

susceptible to Thiophene-2-carboxylic acid hydrozide (TCH or T2H),

niacin negative, &

do not reduce nitrate.

Answer 9

M bovis

Question 10

is resistant to TCH.

Answer 10

Mtb

Question 11

Source of Bacille Calmette-Guerin (BCG) vaccine

Answer 11

M bovis

Question 12

Mycobacterium leprae
• Morphology is similar to

Answer 12

M. tuberculosis

Question 13

• Unculturable on artificial media

Answer 13

Mycobacterium leprae

Question 14

M leprae

• animal experiments:
• optimal growth temp.

Answer 14

armadillos, mouse’ footpads

30°C

Question 15

• never been grown in-vitro cultivation due to a loss or disruption of many of the genes required for metabolism

Answer 15

M leprae

Question 16

M leprae

• a unique carbohydrate antigenic determinant

Answer 16

• surface lipid, phenolic glycolipid 1 (PGL-1)

Question 17

• surface lipid, phenolic glycolipid 1 (PGL-1) - a unique carbohydrate antigenic determinant

Answer 17

M leprae

Question 18

M leprae

• a skin test reagent

Answer 18

• leprosin-A

Question 19

Pathogenesis
• Principal target cell is the Schwann cell (neurolemmocytes, principal glia of the PNS)

Answer 19

Mycobacterium leprae

Question 20

are capable of intracellular growth
• Resulting in nerve damage: anesthesia, muscle paralysis

Answer 20

• M. leprae

Question 21

• Repeated injuries/infections of the anesthetic extremities leads to gradual destruction

Answer 21

M leprae

Question 22

• Infiltration of the bacilli in the skin and cutaneous nerves leads to the formation of visible lesions.

Answer 22

M leprae

Question 23

Disease progression primarily depends on host’s immune responses - immunological spectrum of the disease

Answer 23

M leprae

Question 24

Few erythematous or hypopigmented plaques with flat centers and raised, demarcated borders;

peripheral nerve damage with complete sensory loss: visible enlargement of nerves

Answer 24

Tuberculoid Leprosy

Question 25

Infiltration of lymphocytes around center of epithelial cells; presence of Lang-hans' cells: few or no acid-fast bacilli observed

Answer 25

Tuberculoid Leprosy

Question 26

Infectivity - Low Immune response Delayed hypersensitivity - Reactivity to lepromin Immunoglobulin level - Normal Erythema nodosum leprosum - Absent

Answer 26

Tubercoid leprosy

Question 27

Infectivity - High Immune response Delayed hypersensitivity — Non-Reactivity to lepromin Immunoglobulin levels - Hypergammaglobinemia Erythema nodosum leprosum - usually present

Answer 27

Lepromatous Leprosy

Question 28

Predominantly "foamy" macrophages with few lymphocytes; lack of Lang-hans' cells; numerous acid-fast bacilli in skin lesions and internal organs

Answer 28

Lepromatous Leprosy

Question 29

Many erythematous macules, papules, or nodules extensive tissue destruction (e.g., nasal cartilage, bones, ears); diffuse nerve involvement wit/ patchy sensory loss; lack of nerve enlargement

Answer 29

Lepromatous Leprosy

Question 30

Laboratory Investigation • Clinical diagnosis - confirmed by _________and by the detection of ______in nasal discharges, scrapings from the nasal mucosa and slit-skin smears

Answer 30

histological examination of skin biopsies acid-fast bacilli

Question 31

Laboratory Investigation - obtained from obvious lesions, the ear lobes and apparently unaffected skin.

Answer 31

Smears

Question 32

Laboratory Investigation Stain with_______ method • number of bacilli seen in OlO recorded as bacillary index

Answer 32

Ziehl-Neelsen

Question 33

Laboratory Investigation : patients with clinically active leprosy but no bacilli are seen on slit-skin smear examination

Answer 33

"Paucibacillary" disease

Question 34

Laboratory Investigation : those who are bacilli positive at any site

Answer 34

• "Multibacillary" disease

Question 35

Laboratory Diagnosis • The number of AFB present/OlF after examination of the entire smear

Answer 35

• Bacteriologic Index (BI)

Question 36

Laboratory Diagnosis • The number of solid-staining cells/100 total bacilli examined

Answer 36

• Morphologic index (MI)

Question 37

Laboratory Diagnosis aid the clinician in determining the progress of the disease

Answer 37

BI & MI:

Question 38

Laboratory Diagnosis * those with dense, uniform staining of the entire bacillus with even sides and rounded ends in which length of the bacillus is at least 5x the width of the bacillus.

Answer 38

Solid-staining cells

Question 39

Mycobacterium leprae • Treatment: •__________- 6-month therapy • Rifampicin 600 mg* • Dapsone 100 mg**

Answer 39

Paucibacillary leprosy

Question 40

Mycobacterium leprae ________- 12-month therapy • Rifampicin 600 mg* • Dapsone 100 mg** • Clofazimine 300 mg* and 50 mg**

Answer 40

Multibacillary leprosy

Question 41

Runyon Group / (Slow-Growing

Answer 41

M. kansasii M. marinum M. simiae

Question 42

Runyon Group II (Slow-Growing

Answer 42

M. szulgai M. scrofulaceum M. xenop

Question 43

Runyon Group III (Slow-Growing

Answer 43

M. avium complex M. genavense M. haemophilum M. malmoense

Question 44

Runyon Group IV (Rapid Growers)

Answer 44

M. fortuitum M. chelonae M. abscessus M. mucogenicum