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59 Cards in this Set
- Front
- Back
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What kind of cells do chlamydiae demonstrate tropism for?
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Epithelial cells of mucous membranes or lungs.
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What are three reasons why chlamydiae are not classified as viruses?
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Contain both RNA and DNA
Synthesize proteins Sensitive to antibiotics |
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What diseases are associated with the different C. trachomatis serotypes?
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1) Nongonococcal urethritis and inclusion conjunctivitis of the newborn (D-K)
2) Trachoma (A-C) 3) Lymphogranuloma venereum (L1-3) |
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What disease is associated with C. psittaci?
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Psittacosis,
Pneumonia |
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What disease is associated with C. pneumonia?
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Community-acquired acute respiratory disease and possibly atherosclerosis.
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How many C. pneumoniae serotypes exist?
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One
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Do chlamydiae have a rigid cell wall?
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Yes
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How does the Chlamydiae cell wall differ from that of G- bacteria?
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Chlamydiae lack peptidoglycan
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What toxins or virulence factors are responsible for chlamydiae pathogenesis?
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None:
Chlamydiae do not produce toxins or virulence factors |
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What are the two morphological forms of chlamydiae that are involved in the replicative cycle?
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Elementary body
Reticulate body |
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What is the elementary body?
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An extracellular, infectious small, spore-like particle which is metabolically inert
Elementary body is extracellular |
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How does it enter the cell?
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Through endocytosis into susceptible host cells.
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How does the elementary body escape cell-mediated destruction?
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Inhibiting phagosome-lysosome fusion.
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What is the reticulate body?
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A large, active, replicative, intracelluar particle.
Reticulate body is replicative. |
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How do the reticulate bodies replicate within the cell?
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Binary fission
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What are inclusion bodies?
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Sites of reticulate body replication that appear within cells that can be stained and visualized microscopically.
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Why is Gram stain a poor choice in detecting chlamydiae?
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Chlamydiae exists intracellularly and stain poorly on Gram stain.
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What are two methods for laboratory diagnosis of chlamydiae?
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Giemsa stain
Immunofluorescence |
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What histologic finding is associated with Chlamydia infection?
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Cytoplasmic inclusion bodies
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What is used to grow chlamydiae in cell cultures?
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Cyclohexamide
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Why is cyclohexamide used to grow chlamydiae in cell cultures?
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Cycloheximide inhibits eukaryocyte metabolism enhancing growth of Chlamydia.
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For hich chlamydia species is serology testing NOT useful?
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C. trachomatis
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Why is serology testing NOT useful for C. trachomatis?
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C. trachomatis infection is so frequent tht many people already have antibodies against it.
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What two drug groups are effective for treating chlamydiae?
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1) Tetracyclines
2) Macrolides (azithromycin adn erythromycin) |
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What vaccine is available for chlamydial disease?
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NONE
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What sexually transmitted infection is often found in patients with Chlamydia?
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Gonococcus
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What four diseases are associated with C. tracomatis?
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Nongonococcal urethritis
Inclusion conjunctivitis Lymphogranuloma venereum Trachoma |
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What is the prevalence of nongonococcal urethritis?
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The most common sexually transmitted infection?
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What are three causes of nongonococcal urethritis?
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C. trachomatis
Mycoplasma Ureaplasma urealyticum |
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What are four possible infection patterns in men with c. trachomatis?
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Nongonococcal urethritis
Epdidymitises Prostatitis Proctitis |
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What are three possible infection patterns in women with C. trachomatis?
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Cervicitis
Salpingitis Pelvic inflammatory disease |
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What are two symptoms of nongonococcal urethritis?
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Dysuria with thick, mucoid discharge from the urethra of males or from the cervical os in females
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What percentage of neonates born to C. trachomatis-infected mothers will contract the disease?
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50%
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What are three sequelae of a neonate born to C. trachomatis-infected mothers?
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1) Mucopurulent eye infections, i.e., neonatal inclusion conunctivitis 7-12 days after delivery
2) Chlamydial pneumonitis 2-12 weeks after birth 3) Reiter's syndrome, i.e., urethritis, arthritis,and uveitis. |
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What is the treatment of choice for C. trachomatis infection?
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Azithromycin
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What is inclusion conjunctivitis?
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An acute, purulent infection of conjunctiva around the eye that is named fo rthe inclusions seen in infected conjuntival epithelial cells.
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How can one prevent the development of inclusion conjunctivitis in the newborn?
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Erythromycin eye drops are prophylactically given to all newborns in the US.
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How does C. trachomatis spreat to the newborn?
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Passage through birth canal, i.e., parturition.
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What is lymphogranuloma venereum?
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A sexually transmitted infection characterized by transient papules on genitalia with inguinal/perirectal lymphadenopathy.
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Where is lymphogranuloma venereum endemic?
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South Ameria, Asia, and Africa
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What is the treatment of choice for lymphogranuloma venereum?
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Doxycycline
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What is trachoma?
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Chronic conjunctivitis
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What is the epidemiologic importance of trachoma?
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The leading cause of preventable blindness worldwide.
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When does trachoma induced blindness develop?
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10-15 years postexposure
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What is the pathophysiology of trachoma-induced blindness?
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1) Inflammation
2) Scar traction 3) Inversion of eyelid 4) Corneal scarring caused by eyelash friction against the cornea 5) Secondary bacterial infection 6) Blindness |
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What is the prophylactic treatment for trachoma?
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Topical tetracycline
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How are the inclusions in C. trachomatis-infected epithelial cells visualized?
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Stained with iodine
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Are the majority of genital tract infections caused by chlamydiae symptomatic?
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NO
Especially in women, most infections are asymptomatic, undiagnosed, and untreated |
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What disease is associated with C. pneumoniae?
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Community-acquired acute respiratory infection, frequently asymptomatic
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What organism is susceptible to C. pneumoniae?
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Only humans
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How is c. pneumoniae transmitted?
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Inhalation of aerosols.
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Are teh maority of C. pneumoniae infections symptomatic?
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NO
Mot infections are asymptomatic |
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What evidence indicates that C. pneumoniae is commonly acquired?
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Approximately 50% of adults have developed antibodies to C. pneumoniae
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Does C. pneumoniae cause invasive, disseminated infection?
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Rarely
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What is the treatment of choice for C. psittaci and C. pneumoniae?
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Doxycycline
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What disease is associated with C. psittaci?
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Psittacosis, also known as ornithosis, which are types of pneumonia
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What organisms does C. psittaci infect?
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Birds,
Mammals |
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How does C. psittaci spread to humans?
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Inhalation of organisms in dry bird feces
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What are three symptoms of psittacosis?
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Acute onset of fever
Hacking dry cough Flu-like symptoms |
