L41 Flashcards
Chlamydia
- GP or GN?
- Unique features
GN
Obligate INTRAcell!!
Genome is highly conserved between species
What is the elementary body?
Infectious form
Gets uptaken in vacuoles
What is the replicate body?
Replicating form inside vacuoles
What is the early differentiation phase for chlamydia?
EB –> RB
Exponential RB growth
What is the late differentiation phase?
Inclusion had matured
See asynchronous differentiation of RB –> EB
Describe the characteristics of EB.
Smaller
More dense (b/c NOT replicating)
- Compact DNA
- Histones
Describe the characteristics of RB.
Larger
Replicating = less dense
- Dispersed DNA
- No histones
What are the virulence mechanisms of chlamydia?
ONCE inside the INCLUSION
Type 3 secretion system
Autotransport
Outer membrane blebs
Talk through how chlamydia infects a host cell.
EB adherence via various integrins
EB in vacuole
3 secretion systems to export virulence factors for microbe survival
EB –> RB = inclusion
Early stage - RB proliferation
Mid stage - RB line up along edges of inclusion
Late stage = not synchronous differentiation RB –> EB
Cell lysis and release of EB
Where in the body are chlamydia infections found?
Mucosal surfaces
What are they symptoms of chlamydia infections?
Often asymptomatic!
Can lie dormant as localized infections occur and are resolved without progressing
What happens if you don’t treat a chlamydia infection?
Lasts a long time
Causes inflam –> scarring
Even w/o symptoms
What is the strain of chlamydia causes eye infections and genital STDs?
Chlamydia trachomatis
Talk through the 5 stages of progression of c.trachomatis if untreated.
Inclusion conjunctivitis Follicular conjunctivitis Pannus Trichiasis Blindness
Describe inclusion conjunctivitis.
= initial infection caused by c.trachomatis
Acute, inflam
Can easily treat with antibiotics!!
Describe follicular conjunctivitis.
Delayed HST rxn
B/c of repeated, untreated infections
If resolves on own here - person is immune
What is pannus?
Corneal inflammation –>
- Corneal scar tissue
- Neovascularization
What is trachoma?
Conjunctiva is contracted b/c of scarring
Eyelashes inward –> damage cornea
What eye condition occurs if c.trachomatis infects a newborn? What is the time frame for symptoms?
Opthalmia neonatorum
Not immediate - days after birth
What lung infection occurs if c.trachomatis infect a newborn? What is the time frame for symptoms?
Pneumonia of the newborn
Delayed onset - 3-16 weeks
How do you treat chlamydia infections in newborns?
Erythromycin
Macrolides
What are the genital complication for women if chlamydia goes undiagnosed?
Pelvic inflammatory disease
Ectopic pregnancy
Infertility
What is the natural immunity for genital infections?
B & T cell - Ab & cell mediated
But immunity is short lived
Which strain of chlamydia causes ATYPICAL adult pneumonia?
Chlamydia pneumoniae
What diseases result of chlamydia pneumonia is not diagnosed and treated?
Chronic bronchitis
Asthma
COPD
What condition is associated with disseminated chronic chlamydia pneumoniae infection?
CVD
How do you diagnose chlamydia pnemoniae infection?
General suspicion for atypical pneumonia - not specific tests needed Drugs treat all possible atypical cases: - Doxy - Erythro - Quinolones (Levofloxacin)
Which strain of chlamydia is associated with birds?
Chlamydia psittaci
What are mycoplasma?
No walls - 1 cytoplasmic membrane Many shaped bacteria Hard to grow on culture Cholesterol requirement Diverse genome
How might mycoplasma colonies look?
Fried egg colonies
NOT true for mycoplasma pneumoniae
Which strain of mycoplasma are you particularly aware of?
M.pneumonia
Causes atypical pneumonia
Leading cause of pneumonia in school age children & young adults
How do you diagnose M.pneumoniae infection?
IgG or IgM by ELISA
Which strains of mycoplasma are normal flora but can cause opportunistic STIs?
M. hominis
M. genitalium
U. urealyticum
Which mycoplasma are associated with HIV?
M. fermentans
M. penetrans
