Lecture 6 - Flashcards
1
Q
Mycobacteria
A
- Causative agents of tuberculosis and leprosy
Waxy coat (NO Gram stain, Resistant to disinfectants) - Acid-fast bacilli –> Resist decolorization
- Use Ziehl-Neelsen staining technique
2
Q
Mycobacteria: Ziehl-Neelsen staining
A
- Used for staining Mycobacteria
- You boil the sample on the slide for ten minutes, do remove the wax cell wall
3
Q
Mycobacterium tuberculosis
A
- Chronic slow-progressing pulmonary infection; transmission by aerosol droplets
- Obligate aerobe, facultative intracellular parasite
- 4-6 WEEKS to see colonies on a plate
- —> Use microscopyof sputum smears as firstline of diagnosis
- Leading cause of death world-wide form a single infection
- Infection develops in stages
4
Q
Stages of Mycobacterium tuberculosis
A
- Primary tuberculosis
- Post-Primary tuberculosis
- Immunity tuberculosis
5
Q
Primary tuberculosis
A
- Aerosol inhalation
- Bacteria multiplication in alveoli
- macrophage ingestion of bacilli and formation of 1st complex
- Foci of infection in lungs (may spread to kidneys, bones, meninges)
- CMI is fully active, infection is stopped (majority of cases)
- Some bacilli survive, reactivation several years later
6
Q
Post-Primary tuberculosis
A
- Late reactivation of lesions in lungs, kidneys, bones etc
- 5% of cases; higher in patients with AIDS
- Chronic infection
7
Q
Immunity tuberculosis
A
- Cell mediated immunity is most important (T-cells)•
- Mantoux test
- Tuberculin solution is injected INTRADERMALLY, wait 48-72 hrs, check for induration
- Record diameter of induration
- > 10mm POSITIVE
- 5-9 mm Doubtful, maybe cross reaction with other Mycobacteria
- <4mm NEGATIVE
- A positive test does not necessarily mean there is currently an active infection
8
Q
Mycobacterium tuberculosis:
Laboratory Diagnosis
A
.
9
Q
Non Tuberculous Mycobacteria
A
- Tuberculoid leprosy
- Leopromatous leprosy
10
Q
Non Tuberculous Mycobacteria:
Epidemiology
A
.
11
Q
Non Tuberculous Mycobacteria:
Diagnosis
A
.
12
Q
Non Tuberculous Mycobacteria:
Treatment
A
.
13
Q
Spirochetes
A
1- Treponema Pallidum
2- Lyme Disease
3- Leptospira Interrogans
14
Q
Treponema Pallidum
A
- Syphylis
- Gram Negative, helical bacteria
15
Q
Spirochetes: Syphilis Stages
Treponema Pallidum
A
- Primary syphilis
- Secondary syphilis
- Latent syphilis
- Late syphilis
