L41

Question 1

Chlamydia

• GP or GN?
• Unique features

Answer 1

GN
Obligate INTRAcell!!
Genome is highly conserved between species

Question 2

What is the elementary body?

Answer 2

Infectious form

Gets uptaken in vacuoles

Question 3

What is the replicate body?

Answer 3

Replicating form inside vacuoles

Question 4

What is the early differentiation phase for chlamydia?

Answer 4

EB –> RB

Exponential RB growth

Question 5

What is the late differentiation phase?

Answer 5

Inclusion had matured

See asynchronous differentiation of RB –> EB

Question 6

Describe the characteristics of EB.

Answer 6

Smaller
More dense (b/c NOT replicating)
- Compact DNA
- Histones

Question 7

Describe the characteristics of RB.

Answer 7

Larger
Replicating = less dense
- Dispersed DNA
- No histones

Question 8

What are the virulence mechanisms of chlamydia?

Answer 8

ONCE inside the INCLUSION
Type 3 secretion system
Autotransport
Outer membrane blebs

Question 9

Talk through how chlamydia infects a host cell.

Answer 9

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

Question 10

Where in the body are chlamydia infections found?

Answer 10

Mucosal surfaces

Question 11

What are they symptoms of chlamydia infections?

Answer 11

Often asymptomatic!

Can lie dormant as localized infections occur and are resolved without progressing

Question 12

What happens if you don’t treat a chlamydia infection?

Answer 12

Lasts a long time
Causes inflam –> scarring
Even w/o symptoms

Question 13

What is the strain of chlamydia causes eye infections and genital STDs?

Answer 13

Chlamydia trachomatis

Question 14

Talk through the 5 stages of progression of c.trachomatis if untreated.

Answer 14

Inclusion conjunctivitis 
Follicular conjunctivitis 
Pannus
Trichiasis 
Blindness

Question 15

Describe inclusion conjunctivitis.

Answer 15

= initial infection caused by c.trachomatis
Acute, inflam
Can easily treat with antibiotics!!

Question 16

Describe follicular conjunctivitis.

Answer 16

Delayed HST rxn
B/c of repeated, untreated infections
If resolves on own here - person is immune

Question 17

What is pannus?

Answer 17

Corneal inflammation –>

1. Corneal scar tissue
2. Neovascularization

Question 18

What is trachoma?

Answer 18

Conjunctiva is contracted b/c of scarring

Eyelashes inward –> damage cornea

Question 19

What eye condition occurs if c.trachomatis infects a newborn? What is the time frame for symptoms?

Answer 19

Opthalmia neonatorum

Not immediate - days after birth

Question 20

What lung infection occurs if c.trachomatis infect a newborn? What is the time frame for symptoms?

Answer 20

Pneumonia of the newborn

Delayed onset - 3-16 weeks

Question 21

How do you treat chlamydia infections in newborns?

Answer 21

Erythromycin

Macrolides

Question 22

What are the genital complication for women if chlamydia goes undiagnosed?

Answer 22

Pelvic inflammatory disease
Ectopic pregnancy
Infertility

Question 23

What is the natural immunity for genital infections?

Answer 23

B & T cell - Ab & cell mediated

But immunity is short lived

Question 24

Which strain of chlamydia causes ATYPICAL adult pneumonia?

Answer 24

Chlamydia pneumoniae

Question 25

What diseases result of chlamydia pneumonia is not diagnosed and treated?

Answer 25

Chronic bronchitis Asthma COPD

Question 26

What condition is associated with disseminated chronic chlamydia pneumoniae infection?

Answer 26

CVD

Question 27

How do you diagnose chlamydia pnemoniae infection?

Answer 27

``` General suspicion for atypical pneumonia - not specific tests needed Drugs treat all possible atypical cases: - Doxy - Erythro - Quinolones (Levofloxacin) ```

Question 28

Which strain of chlamydia is associated with birds?

Answer 28

Chlamydia psittaci

Question 29

What are mycoplasma?

Answer 29

``` No walls - 1 cytoplasmic membrane Many shaped bacteria Hard to grow on culture Cholesterol requirement Diverse genome ```

Question 30

How might mycoplasma colonies look?

Answer 30

Fried egg colonies | NOT true for mycoplasma pneumoniae

Question 31

Which strain of mycoplasma are you particularly aware of?

Answer 31

M.pneumonia Causes atypical pneumonia Leading cause of pneumonia in school age children & young adults

Question 32

How do you diagnose M.pneumoniae infection?

Answer 32

IgG or IgM by ELISA

Question 33

Which strains of mycoplasma are normal flora but can cause opportunistic STIs?

Answer 33

M. hominis M. genitalium U. urealyticum

Question 34

Which mycoplasma are associated with HIV?

Answer 34

M. fermentans | M. penetrans