Lecture 6 Flashcards
Mycobacteria
Mycobacteria is a Causative agents for what?
tuberculosis and leprosy
What staining technique is used for myobacteria?
Ziehl-Neelsen staining technique
What type of bacteria is Mycobacterium tuberculosis
Obligate aerobe, facultative intracellular
parasite
What medium is used for Mycobacterium tuberculosis
Lowenstein-Jensen medium
What immunity is used in Mycobacterium tuberculosis
- Cell mediated immunity is most important (T-cells)
Explain the resultus of mantoux test
> 10mm POSITIVE
* 5-9 mm Doubtful, maybe cross reaction with other
Mycobacteria
* <4mm NEGATIVE
What bacteria may give a doubtful result?
Atypical Mycobacteria
Mycobacterium marinum causes what?
skin infections
What are the two types of Mycobacterium leprae
Tuberculoid leprosy and Lepromatous leprosy
Tuberculoid leprosy?
visible nerve enlargement, few bacilli in infected low infectivity
Lepromatous leprosy?
no visible nerve enlargement, many
bacilli in infected tissue; high infectivity
What is the name of the bacteria that causes syphilis?
Treponema pallidum
What happens in primary syphilis?
Appearance of chancre 3-4 weeks after infection
* Fluid from lesion contains bacteria seen under
dark-field microscopy
What happens in Secondary syphilis
6 weeks after appearance of chancre
* Generalized or local rash
What happens in latent syphilis
No symptoms of infection
* Non-transmittable after 4 years
* BUT congenital infection may occur
What happens in late syphilis
Obliterative endarteritis
* Can involve skin, mucosae, nervous system,
cardiovascular system and tissues
Whats the name of the bacteria that cuases lyme disease?
Borrelia burgdorferi
What does Borrelia burgdorferi affect?
Affects skin, joints, nervous system and hear
How is lyme disease diagnosed?
Use serology for diagnosis (ELISA)
Serology does not give +ve result in first 2-4 weeks
of infection
Treatment/ prevention for lyme disease?
Doxycycline, amoxicillin, cefuroxime for early
disease
vaccine available
What type of bacteria is chlamyia
Obligate intracellular energy parasite
Whats special about chlamyia and the way it grows?
- Can NOT make their own ATP or other energy
intermediates - Can NOT be grown on artificial media
What is the life cycle of chlamyia
Elementary body: infectious, no growth or replication
Reticulate body:Replication and growth
What does Chlamydia trachomatis do
Trachoma: blindness
Conjunctivitis in newborns
What is CHLAMYDIA PSITTACI
- Bird pathogen
- Can transmit to humans
- Pneumonia or endocarditis
What is CHLAMYDIA PNEUMONIAE
- Respiratory tract infections, mild pneumonia
- Usually sub-clinical infections
What are the characteristics of myoplasma?
Smallest free-living bacterium
* Lack true cell wall
some are pathogenic
Mycoplasma found where?
Saprophytes, part of normal flora of oropharynx and
genital tract of humans and animals
- MYCOPLASMA PNEUMONIAE
PRIMARY cause of atypical pneumonia
* More common in younger individuals (15-35 years)
GENITAL MYCOPLASMA
Part of normal genital flora
* Rate of colonization increases with number of sexual
partners
Levels (depth) of infection by
fungal pathogens
SKIN
superficial
cutaneous
subcutanous
systemic
BLOODSTREAM
