Lecture 6

Question 1

Mycobacteria is a Causative agents for what?

Answer 1

tuberculosis and leprosy

Question 2

What staining technique is used for myobacteria?

Answer 2

Ziehl-Neelsen staining technique

Question 3

What type of bacteria is Mycobacterium tuberculosis

Answer 3

Obligate aerobe, facultative intracellular
parasite

Question 4

What medium is used for Mycobacterium tuberculosis

Answer 4

Lowenstein-Jensen medium

Question 5

What immunity is used in Mycobacterium tuberculosis

Answer 5

• Cell mediated immunity is most important (T-cells)

Question 6

Explain the resultus of mantoux test

Answer 6

> 10mm POSITIVE
* 5-9 mm Doubtful, maybe cross reaction with other
Mycobacteria
* <4mm NEGATIVE

Question 7

What bacteria may give a doubtful result?

Answer 7

Atypical Mycobacteria

Question 8

Mycobacterium marinum causes what?

Answer 8

skin infections

Question 9

What are the two types of Mycobacterium leprae

Answer 9

Tuberculoid leprosy and Lepromatous leprosy

Question 10

Tuberculoid leprosy?

Answer 10

visible nerve enlargement, few bacilli in infected low infectivity

Question 11

Lepromatous leprosy?

Answer 11

no visible nerve enlargement, many
bacilli in infected tissue; high infectivity

Question 12

What is the name of the bacteria that causes syphilis?

Answer 12

Treponema pallidum

Question 13

What happens in primary syphilis?

Answer 13

Appearance of chancre 3-4 weeks after infection
* Fluid from lesion contains bacteria seen under
dark-field microscopy

Question 14

What happens in Secondary syphilis

Answer 14

6 weeks after appearance of chancre
* Generalized or local rash

Question 15

What happens in latent syphilis

Answer 15

No symptoms of infection
* Non-transmittable after 4 years
* BUT congenital infection may occur

Question 16

What happens in late syphilis

Answer 16

Obliterative endarteritis
* Can involve skin, mucosae, nervous system,
cardiovascular system and tissues

Question 17

Whats the name of the bacteria that cuases lyme disease?

Answer 17

Borrelia burgdorferi

Question 18

What does Borrelia burgdorferi affect?

Answer 18

Affects skin, joints, nervous system and hear

Question 19

How is lyme disease diagnosed?

Answer 19

Use serology for diagnosis (ELISA)
Serology does not give +ve result in first 2-4 weeks
of infection

Question 20

Treatment/ prevention for lyme disease?

Answer 20

Doxycycline, amoxicillin, cefuroxime for early
disease
vaccine available

Question 21

What type of bacteria is chlamyia

Answer 21

Obligate intracellular energy parasite

Question 22

Whats special about chlamyia and the way it grows?

Answer 22

• Can NOT make their own ATP or other energy
  intermediates
• Can NOT be grown on artificial media

Question 23

What is the life cycle of chlamyia

Answer 23

Elementary body: infectious, no growth or replication
Reticulate body:Replication and growth

Question 24

What does Chlamydia trachomatis do

Answer 24

Trachoma: blindness
Conjunctivitis in newborns

Question 25

What is CHLAMYDIA PSITTACI

Answer 25

* Bird pathogen * Can transmit to humans * Pneumonia or endocarditis

Question 26

What is CHLAMYDIA PNEUMONIAE

Answer 26

* Respiratory tract infections, mild pneumonia * Usually sub-clinical infections

Question 27

What are the characteristics of myoplasma?

Answer 27

Smallest free-living bacterium * Lack true cell wall some are pathogenic

Question 28

Mycoplasma found where?

Answer 28

Saprophytes, part of normal flora of oropharynx and genital tract of humans and animals

Question 29

* MYCOPLASMA PNEUMONIAE

Answer 29

PRIMARY cause of atypical pneumonia * More common in younger individuals (15-35 years)

Question 30

GENITAL MYCOPLASMA

Answer 30

Part of normal genital flora * Rate of colonization increases with number of sexual partners

Question 31

Levels (depth) of infection by fungal pathogens

Answer 31

SKIN superficial cutaneous subcutanous systemic BLOODSTREAM