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34 Cards in this Set
- Front
- Back
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What do Chlamydia trachomatis serovars A, B, Ba, and C cause
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Trachoma
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What do Chlamydia trachomatis serovars D-K cause
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Sexually transmitted diseases; urethritis, cervicitis; inclusion conjunctivitis, infant interstitial pneumonia
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What are the two human biovars of Chlamydia trachomatis
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Chlamydia trachomatis serovars A-K
Lymphogranuloma venereum (LGV) |
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What does Chlyamydia trachomatis biovar Lymphogranuloma venereum (LGV) cause
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Sexually transmitted diseases.
Three serovars (LGV 1,2,3) Causes lymphogranuloma venereum, primary urethritis, cervicitis |
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What does Chlamydia pneumoniae (TWAR=Taiwan acute respiratory infection) cause
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Pneumonia, bronchitis, sinusitis. Human transmission
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What does Chlamydia psittaci cause
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Atypical pneumonia, endocarditis, spontaneous abortion in sheep
Zoonotic transmission to man |
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What are the general characteristics of Chlamydia
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obligate intracellular parasites
Small genome, carry plasmids Cell envelope similar to gram negative bacteria but no peptidoglycan. Group specific LPS; type-specific membrane antigens Susceptible to tetracycline, erythromycin |
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How might the life cycle of Chlamydia be described
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Dimorphic life cycle- elementary body (EB) and reticulate body (RB)
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Describe Chlamydia's elementary body
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Small, dense
Extracellular, infectious No metabolic activity or osmotic fragility Cross-linked outer membrane proteins |
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Describe Chlamydia's reticulate body
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Large, homogeneous
Intracellular, replicative Has metabolic activity and osmotic fragility Does not have cross-linked outer membrane proteins |
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What are the three most common Chlamydia species
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Chlamydia trachomatis
Chlamydia pneumoniae Chlamydia psittaci |
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Describe the life cycle of Chlamydia
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Attachment to glycoprotein or glycolipid receptors on columnar epithelial cells of mucous membranes. Displays tissue tropism
Entry/Penetration- induced endocytosis; multiple mechanisms? Multiplication within inclusion vacuole Release of infectious EBs by lysis of host cell |
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How does Chlamydia multiply within an inclusion vacuole
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Converts from EB to RB
Utilizes host ATP for energy Blocks fusion of vacuole with lysosome Divides, enlarges, inhibits apoptosis Matures to EB |
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What are Chlamydia's direct cytopathic effects on host cells
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Cells vacuolate and degenerate 24-72 hrs after infection
Deciliation of epithelia; disruption of processing and packaging functions of secretory epithelial cells |
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What is the immune pathogenesis of Chlamydia
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Heat shock proteins may lead to inflammation
Acute and chronic inflammation at site of infection Scarring of conjunctivae, Fallopian tube scarring |
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What causes trachoma
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Chlamydia trachomatis serovars A, B, Ba, and C
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What is trachoma
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Bacteria inoculated into the eye by contaminated hand grows in the epithelial cells of the conjunctiva. Local immune reaction causes follicular conjunctivitis that can heal or become chronic. Chronic leads to growth of pannus across the cornea
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What is the epidemiology of trachoma
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Leading cause of preventable blindness affecting 500 million people. Hyperendemic in Africa and Asia
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What causes Adult inclusion conjunctivitis
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Chlamydia trachomatis Serovars D-K
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What is Adult inclusion conjunctivitis
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Acute follicular conjunctivitis with edema, erythema and mucopurulent discharge. Resembles trachoma but scarring of eyelids and pannus formation do not usually occur (no blindness). Associated with genital infections
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What is the most common cause of STDs in the US
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Sexually transmitted diseases cause by Chlamydia trachomatis serovars D-K
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Describe non-gonococcal urethritis and acute epididymitis in males
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Chlamydia trachomatis serovars D-K. Urethral irritation; urethral discharge is clear to mucopurulent
Persistent urethral leukocytosis. Partner transmission 70% N. Gonorrhoea+Chlamydia=20% |
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What causes acute urethral syndrome, mucopurulent cervicitis, salpingitis, and pelvic inflammatory disease (PID) in females
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Chlamydia trachomatis serovars D-K. Most women will be asymptomatic. Symptoms may be subtle
Infection may lead to sterility, ectopic pregnancies, miscarriages, low birth weight babies |
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Describe neonatal infections caused by Chlamydia trachomatis serovars D-K
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Ocular infections- acute mucopurulent eye discharge. Picks up infection from mother. Most common form of neonatal conjunctivitis in the US
Infant interstitial pneumonia- gradual onset, no fever |
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What do Chlamydia trachomatis serovars L1, L2, L2a, and L3 cause
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Lymphogranuloma venereum
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Describe Lymphogranuloma venereum
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LGV strains show tropism for lymphoid cells.
Primary lesion is small, near genitalia. Heals spontaneously Later, regional lymphadenopathy occurs. Fever, chills, headaches, arthralgia, myalgia Late phase includes sequelae due to changes in lymph drainage, like perirectal abscesses and fistulas |
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What is Psittacosis, which is caused by Chlamydia psittaci
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Primary atypical pneumonia
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What is the main disease caused by Chlamydia pneumoniae
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Walking pneumonia, similar to the disease caused by Mycoplasma pneumoniae
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How are Chlamydia infections diagnosed
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Screening is important
Growth in cell culture, but it's slow Scrapings from infected eye or genital tract |
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How will Chlamydia trachomatis be distinguished from C. pneumoniae and C. psittaci in a stain
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C. trachomatis inclusions contain glycogen and stain reddish brown with iodine. C. pneumoniae and C. psittaci do not contain glycogen
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How is trachoma treated
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Antibiotics early, surgery to repair scarring
No acquired immunity to reinfection |
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How are Chlamydia STDs treated
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Azithromycin (1), ofloxacin, tetracycline, doxycycline
Give doxycycline 21 days for LGV |
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How is Chlamydia-induced infant conjunctivitis treated
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Oral erythromycin; not silver nitrate
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How are Chlamydia-induced Psittacosis and pneumonia treated
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Tetracycline and erythromycin
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