Microbiology- Sexually Transmitted Diseases: Intro and Chlamydia
Why are LGV serovars more invasive than other serovars
Because they replicate in phagocytes
**After biovars, how is C. Trachomatis differentiated:
By SEROVARS, based on major outer membrane protein (MOMP) (each leads to a different immune response)
Acute conjunctivitis in sexually active adults commonly caused by:
C. Trachomatis
Reiter Syndrome Triad and Causative Agent
C. Trachomatis Triad: urethritis, conjunctivitis, polyarthritis
Cause of Chronic Conjunctivitis:
C. Trachomatis. Destruction of conjunctiva and folding.
What is the most reported STD in the US?
Chlamydia (C. Trachomatis)
What is the most common species of Chlamydia:
Chlamydia Trachomatis
What is the leading cause of preventable blindness?
Chronic Chlamydia Conjunctivitis
Serovars of C. Trachomatis that cause disease of the urogenital tract:
D-K
Disease by C. Trachomatis is due to:
Destruction of epithelia and the pro inflammatory cytokine response.
**Presentation of Lymphogranuloma Venereum:
**SINGULAR, PAINLESS lesion/papule at site of infection with OVAL edges. ** AND **inguinal lymphadenopathy**.
Most common age range for infection by C. Trachomatis:
20-24 (15-24 overall)
Presentation of Neonatal Conjunctivitis:
5-12 days following birth > eyelid swelling and discharge.
Annual new infections of STDS:
50 million
Young people (15-24) represent what % of all new reported STIs?
50%
*C. Trachomatis UG Infection in Women mainly:
80% are asymptomatic and they serve as reservoir for infection
Serovars of C. Trachomatis that cause Trachoma:
A, B, Ba, C
**Treatment of C. Trachomatis Infection:
Doxycycline or Macrolides
Life Cycle of Chlamydia:
Elementary bodies infect > EBs become reticulate bodies > INCLUSION formed of RBs> elementary bodies formed and released for more infection. All within 72 hours.
Two distinct stages of Chlamydia's life cycle:
Elementary: infectious. Reticulate: replicative (will divide)
Elementary bodies characteristics versus Replicative Bodies:
Elementary= small with rigid cell wall and adapted for extracellular survival Reticulate: adapted for intracellular growth.
Without treatment, C. Trachomatis can lead to what in women:
Fibrosis (fertility implicated)
C. Trachomatis is a common cause of:
Genital infection and conjunctivitis
What is the host of C. Trachomatis:
Humans are ONLY known host.
**Serovars of C. Trachomatis that cause LGV:
L1-L3
What type of C. Trachomatis infection is highly prevalent in Africa, Asia and S. America or associated with TRAVEL?
Lymphogranuloma Venereum (LGV)
What patient group have the highest rate of STIs?
MSM
C. Trachomatis UG Infection in Women- Symptoms:
Mucopurulent Discharge. May also lead to pelvic inflammatory disease
**Diagnosis of C. Trachomatis:
Must have EPITHELIAL CELLS > iodine identifies glycogen inclusions in RETICULATE bodies
Cause of Neonatal Conjunctivitis:
Neonate exposed at birth to C. Trachomatis
**Test of Choice for C. Trachomatis Diagnosis:
Nucleic acid amplification from **URINE or DISCHARGE** (Also used for gonorrhoeae)
Chlamydia characteristics:
Obligate intracellular pathogen (cannot make own ATP). Have a G(-) like envelope but NO PEPTIDOGLYCAN. EB + RBs
Reason for number of new cases of bacterial STDs outnumbering existing cases:
They are treatable
Chlamydia is a bacteria, but what makes it different from most bacteria?
They replicate ONLY within cells (intracellular pathogen) They LACK peptidoglycan/cell wall
The two biovars of C. Trachomatis:
Trachoma and LGV
Diseases caused by C. Trachomatis (5):
Trachoma. Inclusion conjunctivitis. STI/Urogenital infections. Lymphogranuloma venereum (LGV) Infant pneumonia
Tropism of C. Trachomatis:
Tropism for NON-CILIATED, columnary, cuboidal or transitional epithelial cells
**C. Trachomatis UG Infection in Men- Symptoms:
Urethritis with dysuria Thin urethral MUCOPURULENT discharge.
What patient group typically have lowest rate of STIs:
WSW
