Microbiology: Chlamydiaceae and Rickettsiaceae Families

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Questions and Answers

What is the main method of multiplication for Chlamydiaceae?

Budding

Conjugation

Mitosis

Binary fission (correct)

Which of the following diseases is caused by Rickettsiaceae rickettsii?

Epidemic typhus

Lyme disease

Rocky Mountain spotted fever (correct)

Endemic typhus

What unique observation is used to diagnose Anaplasmataceae infections?

PCR amplification of 16S rRNA

Presence of endospore formation

Identification of morulae in leukocytes (correct)

Visualizing motility through flagella

What is the primary vector for transmitting Coxiella burnetii?

Aerosols Signup and view all the answers

Which of the following diseases is characterized by a 'bull's-eye' rash during its early stage?

Lyme disease Signup and view all the answers

Which organism is responsible for causing pelvic inflammatory disease (PID)?

Chlamydia trachomatis Signup and view all the answers

What stage of syphilis is characterized by the presence of a chancre?

Primary stage Signup and view all the answers

Which species causes relapsing fever?

Other Borrelia species Signup and view all the answers

What is the main transmission route for Ehrlichia chaffeensis?

Lone star tick bites Signup and view all the answers

What distinguishes Mycoplasma pneumoniae from other bacterial families?

Small size and lack of a cell wall Signup and view all the answers

What is the primary role of the reticulate body in the Chlamydiaceae family?

To multiply and produce ATP Signup and view all the answers

Which of the following routes is NOT associated with the transmission of Coxiella burnetii?

Ingestion of contaminated food Signup and view all the answers

What characterizes the Gram-negative-like cell wall structure of Chlamydiaceae and Rickettsiaceae?

Outer membrane with lipopolysaccharides Signup and view all the answers

What is the incubation period for Rickettsiaceae infections after transmission through vector bites?

3-14 days Signup and view all the answers

Which disease is associated with Leptospira interrogans and can lead to severe complications?

Weil's disease Signup and view all the answers

In the context of spirochetes, which organism is known for primarily being transmitted through sexual contact or transplacental?

Treponema pallidum Signup and view all the answers

What observation is crucial for diagnosing infections from the Anaplasmataceae family?

Identification of morulae in leukocytes Signup and view all the answers

Which feature distinguishes Mycoplasma pneumoniae from other bacterial organisms?

Absence of a cell wall Signup and view all the answers

What is the vector for Anaplasma phagocytophilum, the causative agent of human granulocytic anaplasmosis?

Lone star tick Signup and view all the answers

Study Notes

Chlamydiaceae Family

Obligate intracellular parasites, possessing a gram-negative-like cell wall.
Contains DNA, RNA, and ribosomes; relies on host ATP for energy.
Multiplies via binary fission.
Two forms: Elementary body (infectious) and Reticulate body (metabolically active, non-infectious).
Chlamydia trachomatis: Infects epithelial cells in mucous membranes, causing:
- Trachoma: Leading cause of preventable blindness.
- Lymphogranuloma Venereum (LGV): Sexually transmitted infection (STD) prevalent in tropical regions.

Rickettsiaceae Family

Obligate intracellular parasites transmitted by arthropod vectors (ticks, lice).
Incubation period: 3-14 days.
Multiplies within endothelial cells.
Common symptoms: Rash, fever.
Rickettsia rickettsii: Causes Rocky Mountain spotted fever, vectored by ticks.
Rickettsia prowazekii: Causes epidemic typhus, transmitted by human body lice.
Rickettsia typhi: Causes endemic typhus, vectored by fleas.

Anaplasmataceae Family

Diagnosed through observation of morulae (bacterial clusters) within leukocytes.
Ehrlichia chaffeensis: Causes human monocytic ehrlichiosis, transmitted by the lone star tick.
Anaplasma phagocytophilum: Causes human granulocytic anaplasmosis.

Coxiella

Diagnosis often uses immunofluorescence.
Requires Biosafety Level 3 laboratory containment.
Coxiella burnetii: Causes Q fever, transmitted through aerosols, ticks, and can survive outside hosts.

Mycoplasmataceae Family

Small bacteria lacking a cell wall.
Mycoplasma pneumoniae: Causes tracheobronchitis (walking pneumonia).
Mycoplasma hominis: Causes pelvic inflammatory disease (PID) and postpartum fever.
Mycoplasma genitalium/urealyticum: Causes nongonococcal urethritis (NGU).

Spirochetes

Helically coiled, motile bacteria with gram-negative-like walls.
Motility facilitated by periplasmic flagella.
Borrelia burgdorferi: Causes Lyme disease, carried by deer ticks.
- Early stage: Erythema migrans rash.
- Disseminated stage: Bacteria spreads to CNS and heart.
- Chronic stage: Potential arthritis.
Other Borrelia species: Cause relapsing fever.
Treponema pallidum: Causes syphilis, transmitted through sexual contact or transplacental.
- Stages: Primary (chancre), Secondary (rash), Tertiary (gummas).
- Subspecies:
  - T. pallidum pertenue: Causes yaws from direct contact.
  - T. pallidum bejel: Non-sexually transmitted syphilis.
  - T. pallidum carateum: Causes a papule with a red halo.
Leptospira interrogans: Causes leptospirosis, transmitted through contact with animal urine, infected soil/water, a severe form called Weil's disease.

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Description

Test your knowledge on the Chlamydiaceae and Rickettsiaceae families of microorganisms. This quiz covers their characteristics, methods of multiplication, and the diseases they cause. Understand the significance of these obligate intracellular parasites and their impact on human health.