chlamydia Flashcards

1
Q

Chlamydia species

A

Chlamydia trachomatis, Chlamydia psittaci, and Chlamydia pneumoniae.

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2
Q

Chlamydia structure

A

Gram negative cocci or coccobacilli. Cell wall is atypical (peptidoglycan does not contain N-acetylmuramic acid). Small genome

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3
Q

Chlamydia growth characteristics

A

obligate intracellular bacteria. Cant synthesize ATP or oxidize NADP (they depend on host cell for energy).

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4
Q

chlamydia visualization

A

visualized by staining infected cells with Giemsa’s stain. Individual bacteria are not observed, but characteristic intracellular inclusions forming compact masses can be observed near the nucleus. Lugols iodine stains C. trachomatis inclusions brown b/c glycogen matrix

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5
Q

Infectious form of Chlamydia

A

Elementary bodies are the infectious form- they have a condensed chromosome with electron-dense centers.

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6
Q

Vegetative form of chlamydia

A

Reticulate bodies- multiply intracellularly

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7
Q

Describe the life cycle of Chlamydia

A

Binary fission. Biphasic life cycle. Elementary bodies enter cell by endocytosis > Ebs are sequestered in inclusion > Differentiation into reticulate body > RBs develop in membrane bound vacuole via metabolic changes and reorganization of chromosome > RBs replicate for 24-72 hrs via binary fission > RBs reorganize and condense to form new EBs > host cell ruptures and frees EBs which infect other host cells

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8
Q

Chlamydia antigens

A

LPS is common to all chlamydia. Specific outer membrane proteins (e.g., MOMP, 61 kD, 33 kD, 14 kD) are used to serotype the Chlamydia, and each serotype is associated with a particular disease

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9
Q

chlamydia pathogenosis

A

Adhesins allow for attachment. Inhibit phagolysosome fusion. May cause latent infection

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10
Q

Transmission of C. trachomatis

A

direct personal contact among humans (e.g. sexual transmission)

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11
Q

Transmission of C. Psittaci

A

transmitted to humans by inhalation of bacteria in droplets or dust from birds and fowl

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12
Q

Transmission of C. pneumoniae

A

transmitted by aerosols from person to person

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13
Q

Chlamydia toxins

A

A heat-labile toxin is produced by infectious Chlamydia. The toxin is lethal to mice when injected intravenously. The specific role of the toxin in pathogenesis is unknown. Each serotype of Chlamydia produces a specific toxin

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14
Q

Chlamydia latency

A

C. trachomatis may exist in a latent condition and be reactivated if an individual becomes immunosuppressed

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15
Q

List the diseases caused by C. trachomatis and the serovariant

A

Serovariant A-C: trachoma, conjunctivitis. D-K: STDs, infant conjunctivitis, and pneumonia. L1-L3: lymphogranuloma venereum.

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16
Q

List diseases caused by C. psittaci

A

Psittacosis (acquired from contact with birds)

17
Q

List diseases caused by C. pneumoniae

A

Pneumonia, upper respiratory disease

18
Q

Clinical manifestations of trachoma

A

Incubation period of 3-10 days. Conjunctivitis and follicular hypertrophy. Persistence of the infection produces corneal scarring and conjunctival deformity as a result of the severe inflammatory response. Scarring causes the eyelids to turn inward (trichiasis) thereby allowing the eyelashes to continually abrade the cornea.

19
Q

Hows is trachoma acquired

A

The infection generally is acquired in infancy from the mother or other close contact

20
Q

Trachoma treatment

A

surgery, antibiotics, facial cleanliness, environmental improvement

21
Q

Clinical manifestations of inclusion conjunctivitis

A

Mucopurulent conjunctivitis beginning 7-12 days after delivery. Infection may disseminate and cause pneumonia

22
Q

prevention/treatment of inclusion conjunctivitis

A

Antibiotics to infected pregnant women. Topical erythromycin or tetracycline, sometimes in combination with systemic antibiotics

23
Q

C. trachomatis urogenital tract infection (STD) clinical manifestations- uncomplicated

A

75% of women and 50% of men have no symptoms. In men, urethritis with dysuria and purulent discharge (PMNs but no bacteria seen on microscope). In women, mucopurulent urethritis, cervicitis and acute urethral syndrome

24
Q

C. trachomatis urogenital tract infection (STD) clinical manifestations of complications

A

Men: Epididymitis, proctitis, urethral stricture, disseminated infection, reactive arthritis. Women: Pelvic inflammatory disease, tubal infertility, ectopic pregnancy, bartholinitis, perihepatitis

25
Q

What proportion of women with PIC have c. trachomatis and what are the long term outcomes

A

50% of women with PID are infected with C. trachomatis. Can lead to scarring of fallopian tubes resulting in infertility, ectopic pregnancy, and chronic pelvic pain.

26
Q

which bacteria often co-occurs with c. trachomatis

A

N. gonorrhea

27
Q

c.trachomatis epidemioogy

A

Most frequently reported infectious disease in the United States

28
Q

Diagnosis of C. trachomatis

A

Nucleic acid amplification technology (NAAT) can be done with a urine sample or swab from the cervix or urethra. Tissue culture isolation is less sensitive and takes up to a week (NAAT only takes 4 hrs)

29
Q

Prevention/ treatment of c. trachomatis

A

Condomes/diaphragms. A single dose of azithromycin or 7 days of doxycycline (twice daily) are the most commonly used treatments. HIV-positive persons with chlamydia should receive the same treatment as those who are HIV negative

30
Q

Clinical manifestations of lymphogranuloma venereum

A

Begins as a small ulcer on the genitalia. The inguinal lymph nodes become swollen, and in 2 to 6 weeks they may suppurate and form draining sinuses. The initial lesion usually has disappeared by this stage. Lymphogranuloma venereum is one of the few chlamydial infections that can disseminate. The peritoneum may become involved, especially in women. Infection of the lower bowel in homosexual men causes a syndrome of ulcerative colitisBegins as a small ulcer on the genitalia. The inguinal lymph nodes become swollen, and in 2 to 6 weeks they may suppurate and form draining sinuses. The initial lesion usually has disappeared by this stage. Lymphogranuloma venereum is one of the few chlamydial infections that can disseminate. The peritoneum may become involved, especially in women. Infection of the lower bowel in homosexual men causes a syndrome of ulcerative colitis

31
Q

lymphogranuloma venereum epidemiology

A

It principally occurs in Africa and South America. The disease is rare in North America

32
Q

lymphogranuloma venereum treatment

A

Sulfonamides and tetracycline are very effective in early stages. Later stages require surgery

33
Q

How are the rates of chlamydia changing over time

A

They are increasing in men and women