Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Respiratory > Micro TB > Flashcards

Micro TB Flashcards

1
Q

Species of

Mycobacteria :

A 
❖ Mycobacterium tuberculosis complex
cause tuberculosis.
❖ Mycobacterium leprae causes
leprosy.
❖ Atypical Mycobacteria /
Mycobacteria other than
tuberculosis ( MOTT) cause
infections in immunosuppressed
patients.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Mycobacterium

tuberculosis complex

A

1- M. tuberculosis (human type) very common
2- M. bovis (bovine type) (rare because of
pasteurization of milk)
3- M. Africanum
4- BCG strains (used for vaccination but in rare
cases it can cause TB in immunocompromised children)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Characteristics of the Genus Mycobacteria

A

Slim, rod shaped, non-motile, do not form spores
Do not stain by Gram stain because it Contain high
lipid conc. ( Mycolic acid ) in the cell wall which
resist staining.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Mycobacterium stains

A

Ziehl-Neelsen ( Z-N ) and

Auramine staining

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Pathogenesis of Tuberculosis : 1

A

Mycobacteria acquired
by airborne droplet
reaches the alveolar
macrophages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Pathogenesis of Tuberculosis : 2

A 
This starts cell mediated
immune response; which
controls the
multiplication of the
organism but does not
kill it.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Pathogenesis of Tuberculosis : 3

A

Granuloma is formed,
organism lives in
dormant state (latent
tuberculosis infection).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Pathogenesis of Tuberculosis : 4

A

Patient show evidence of
delayed cell mediated
immunity ( CMI ).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Pathogenesis of Tuberculosis : 5

A

Disease results due to

destructive effect of CMI.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Non-pulmonary TB :

A 
TB of lymph nodes (cervical, mesenteric)
● TB meningitis (specifically in children, immunocompromised and old people)
● TB bone & joint
● TB of the genitourinary system.
● TB miliary (Blood and other organs.)
● TB of soft tissue (cold abscess):
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

TB of soft tissue (cold abscess

A

lacks inflammation with Caseation (shows no signs of inflammation)
Caseation: due to delayed hypersensitivity reaction. Contains many bacilli ,enzymes, O2,N2 intermediates,
necrotic center of granuloma with cheesy material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Secondary TB Clinically: signs

A

fever, cough,
hemoptysis ,weight loss &
weakness.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Source of secondary TB

A

Endogenous (reactivation of an
old TB)
Exogenous (reinfection with
new strain)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Immunity to Tuberculosis

A

Cell-mediated immunity associated with delayed hypersensitivity reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Immunity to Tuberculosis detection and duration ?

A

Detected by tuberculin skin test

2-10 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Tuberculin Skin Test NEGATIVE

A 
➢ No previous infection
➢ Pre-hypersensitivity
stage
➢ Lost TB sensitivity
with loss of antigen
17
Q

Tuberculin Skin Test POSITIVE
1. >5mm induration
positive in:

A 
1. >5mm
induration
positive in:
❖ Recent
contact with
active TB
❖ HIV or high
risk of HIV
❖ Chest X-ray
consistent
with healed
TB
18
Q

Tuberculin Skin Test POSITIVE
2. >10mm induration
positive in:

A 
2. >10mm induration
positive in:
❖ IV drugs user
❖ HIV seronegative* patient
❖ medical conditions eg:
diabetes, malignancy
❖ Residents & employee at high
risk, and also patients from
country with high incidence
❖ Children < 4 years or exposed
to adult high risk group
19
Q

Tuberculin Skin Test POSITIVE
3. >15mm
induration
positive in

A 
3. >15mm
induration
positive in:
❖ Any persons
including
those with no
risk of TB
20
Q

Laboratory Diagnosis of TB

1) Specimens

A 
Pulmonary TB: 3 early morning(1)
sputum samples or bronchial lavage(2)
or gastric washing(3) (infants)
❖ TB Meningitis: Cerebrospinal fluid (
CSF).
❖ TB of the genitourinary system: 3
early morning urine.
❖ TB bone &amp; joint:Bone, joint aspirate.
❖ TB of lymph nodes: pus or tissues,
NOT swab.
❖ Repeat the sample.(4)
21
Q

Laboratory Diagnosis of TB Direct microscopy of

specimen

A

Z-N or (Auramine ) stain.

22
Q

Laboratory Diagnosis of TB 3) Culture

A

Culture: the gold standard.
Important for identification and
sensitivity.

23
Q

the gold standard.
Media used:

it contains ?

A

Media used:
Lowenstein-Jensen media (LJ).

Media contains: eggs,
asparagine, glycerol, pyruvate/
malachite green.*

24
Q

the gold standard. appearance :

A 
Colonies appear in LJ media
after 2-8 weeks as eugenic,
raised, buff,
 adherent growth -enhanced by glycerol: (MTB)
-enhanced by pyruvate:
(M.bovis).
25
Q

Laboratory Diagnosis of TB

Other media plus LJ media may be used:

A

Fluid media (middle Brook).
Automated methods
Measurement Interferon –gamma release assay (IGARAs)
Molecular method

26
Q

Automated methods

A

Bactec MGIT ( Mycobacteria Growth Indicator Test ).

27
Q

Measurement Interferon –gamma release assay (IGARAs):

A

Measurement Interferon –gamma release assay (IGARAs): positive in latent TB

IF-γ) secreted from
sensitized lymphocytes challenged by the same mycobacterial proteins in a patient previously exposed
to disease, will produce interferon gamma. Has a specific significance than tuberculin skin test.
(increased risk of developing TB).

28
Q

Molecular method

A

1-ProbTech ;detects nucleic acid directly from respiratory samples.
2-Xpert MTB/RIF detect nucleic acid and resistance to rifampicin .
3-PCR(polymerase chain reaction): molecular test directly from
specimen (CSF).

29
Q

Management of a TB case

A

❖Isolation for 10-14 days ( for smear positive cases i.e. > 1000 organisms / ml of sputum
considered infectious case ).
❖ Triple regimen of therapy. Why? (combination of 3 or 4 drugs)
1. To prevent resistant mutants
2. To cover strains located at different sites of the lung
3. To prevent relapse
❖ Treatment must be guided by sensitivity testing.

30
Q

Treatment of TB

First Line Treatment

A 
❖ Isoniazid (INH)
❖ Rifampicin (RIF)
❖ Ethambutol (E)
❖ Pyrazinamide (P)
❖ Streptomycin (S)
❖ Directly Observed Therapy (DOT).
31
Q

Treatment of TB
First Line Treatment
For the first 2 months →
the next 4-6 months →

A

For the first 2 months → INH + RIF + P or E +S For

the next 4-6 months → INH + RIF

32
Q

Treatment of TB Second Line Treatment

A 
❖ PASA ( Para-Aminosalicylic acid).
❖ Ethionamide.
❖ Cycloserine.
❖ Kanamycin.
❖ Fluoroquinolones.
33
Q

Prevention of TB

A

❖ Tuberculin testing of herds.
❖ Slaughter of infected animals.
❖ Pasteurization of milk to prevent bovine TB.
❖ Recognition of new cases.
❖ Prophylaxis with INH of contacts.
❖ Follow up cases.
❖ Immunization with BCG (live attenuated) to all newborns

34
Q

Tb is transmitted by

A

inhaling Aerosols not droplets

35
Q

waxy substance that prevents the Tb from being stained by gram stain.

A

Mycolic Acid

36
Q

will increase the risk of Tb Meningitis

A

Not taking the BCG vaccine

37
Q

can be given as an anaphylactic

A

INH

38
Q

Which test can be used to predict the future of Tb?

A

Quantiferon because it’s specific

Respiratory (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions