Chlamydia - Bailey

Question 1

Chalmydiae is gram ______ & has ______ outer membrane.

Answer 1

• Negative

- LPS

Question 2

True or false, Chlamydiae has no peptidoglycan in the cell walls?

Answer 2

True!

Question 3

What is the size of Chlamydiae?

Answer 3

Small (.25um - .8um)

Question 4

______ is the leading cause of preventable blindness in the world & the most common agent of sexually transmitted bacterial infections.

Answer 4

Chlamydial infections

Question 5

How do Chlamydial infections occur? Exposure? Infection? Spread?

Answer 5

Exposure = Droplet or direct contact.
Infection = mucosal epithelial cells
*Localized usually eyes, lungs & genitalia
Spread by the 4 F's:
Fingers
Flies
Fomites
Fornication

Question 6

Chlamydial are “energy parasites” this means they depend on the host for _____.

Answer 6

ATP

Question 7

Chlamydiae is classified as a _______.

Answer 7

Obligate intracellular pathogen

*Grows only inside or on live tissues (Human, animals, insects..)

Question 8

What are the 4 species of Chlamydia?

Answer 8

1. C. trachomatis
2. C. pneumoniae
3. C. psittaci
4. C. pecorum
   * 1 & 2 are primarily human pathogens
   * 3 & 4 are primarily animal pathogens but can cause disease in humans

Question 9

Tell me about C. Trachomatis infections in men and women…

Answer 9

Genital tract infections
Men = prosititis , epididymitis
Women = Cervicitis, PID, premature births, pelvic pain & newborn eye and lung infection.
Both = Urethritis, infertility, proctitis and arthritis.
*Usually asymptomatic in females.

Question 10

True or false?

C. trachomatis infections are always chronic?

Answer 10

False! They can be acute or chronic.

*During birth infants can contract an infection leading to conductivity and pneumonia if the mother has C. Trachomatis.

Question 11

Describe how C. Trachomatis enters the cell….

Answer 11

• While still outside the cell it exists in Elementary body transit form (EB)
• The EB’s masquerade as nutrients, growth factor, hormones to bind to specific receptors
• EB’s are then internalized by receptor-mediated endocytosis.

Question 12

How do EB’s modify the endocytic vesicle?

Answer 12

2 ways!

• maintain pH above 6.2 preventing vesicle from fusion with lysosomes
• Vesicle is also modified with host components (glycolipids) for camouflage.

Question 13

After infiltration of the cell, infectious EB’s change into what?

Answer 13

Larger intracellular active organisms called (RB’s)

Question 14

What do RB’s do?

Answer 14

Synthesize molecules using host metabolites and energy

*Divide by binary fission.

Question 15

How quickly do RB’s develop?

Answer 15

Slowly

2-3 days per cycle

Question 16

How do RB’s uptake nutrients?

Answer 16

They have tubelike structures that act as straws and allow them to feed on the eukaryotic host cell without leaving the inclusive vacuole. *18-23 hollow tubes per RB.

Question 17

What is Trachoma?

Answer 17

Ideas caused by strain of C. trachomitis.

• Inflammation of the conductive can cause blindness, scarring of cornea.
• spread by direct contact with eye, nose and throat secretions from affected individuals or indirect contact (Washcloth) .

Question 18

What is Lymphogranuloma Venerum?

Answer 18

an STD.

-Systemic, invasive infection apparent in the lymph nodes that drain the genital tract. (Not as common is US)

Question 19

What is quite possibly the most prevalent chlamydial pathogen in the human population?

Answer 19

Chlamydophila pneumoniae

- 50% of people up to age 20 have been infected, 80% of older people have.

Question 20

_________ can be directly observed in 40-100% of patients with atherosclerotic heart lesions.

Answer 20

Chlamydophlia pneumoniae

Question 21

What is the treatment for Chlamydia?

Answer 21

Antibiotics must be maintained for a long time because the organisms grow slow.

There are 4 membranes that must be penetrated:

1. host cell plasma membrane
2. Inclusion membrane
3. Chlamydial outer membrane
4. Chlamydial cytoplasmic membrane

*Antimicrobial target active RB’s

Question 22

What are the characteristics of Rickettsiae? (3 things)

Answer 22

• small gram negative rods
• Obligate intracellular bacteria
• *Zoonoses = infections transmitted from animals to humans.

Question 23

Describe how Rickettsiae obtains “energy”…

Answer 23

• NOT a energy parasite like Chlamydiae

* Can synthesize some of their own ATP and are capable of independent metabolism.

Question 24

How is Rickettsiae transmitted?

Answer 24

Ticks! aka (Bloodstream)

• Larva ticks feed on rodents and then on large mammals as adults (Where they can become infected with R. Rickettsii)
• They can then infect a human if they bite them.
• Once a tick is infected it is infected for life.

Question 25

How does Rickettsaie spread and multiply in the bloodstream?

Answer 25

- Attaches to small blood vessels and induces endocytosis | - once inside, they lyse the phagosome and enter the cytosol.

Question 26

What is the mode of exit for Rickettsaie?

Answer 26

Mode of exit varies... - R. Prowazekii exists by cell lysis - R. rickettsia get extruded from the cell through local projections (Filopodia) *actin in the host cell helps push the bacteria through this projection) - R. tsutsugamushi exits bu budding through the cell membrane (remains enveloped in host cell membrane as it infects other cells.

Question 27

What does Rickettsiae do to the host?

Answer 27

Lysis of the cells result in leakage of blood which causes a rash (Hemorrhagic spots) - Organisms can travel to other vessels including brain and heart. * 75% of patients will clear the infection even before antimicrobial treatment.

Question 28

What are the 3 Typhus group fevers?

Answer 28

1. R. Prowazekii 2. R. Typhi 3. Orientia tsutsugamushi (scrub typhus)

Question 29

What causes typhus fever?

Answer 29

R. Prowazekii (Transmitted by human lice) *Reservoir is humans and flying squirrels

Question 30

What causes murine typhus?

Answer 30

R. Typhi | *transmitted by rats and rat fleas.

Question 31

What is unique about Scrub typhus?

Answer 31

NO RASH! unlike the others. | - caused by Orientia tsutsugamushi

Question 32

What is Ehrlichia? Transmission? Infection? Symptoms?

Answer 32

- Its an obligate intracellular bacteria - Transmitted by Lone Star Tick (This is the Walker Texas Ranger of ticks) - Infects mostly monocytes and macrophages. - symptoms include: fever, malaise, headache and myalgia. * Develops in host cell vacuoles first last reticulate cells and then as dense core cells.

Question 33

How is Rickettsioses diagnosed? (4 ways)

Answer 33

- antibody filters - fluorescent antibody assay - Complement fixation - Latex agglutination

Question 34

4 Fun facts about Mycoplasma! GO!

Answer 34

- Smallest organisms capable of growth on cell free media. - Lack a cell wall (Not sensitive to penicillin!) - Cell membranes contain sterols - Found in other mammals and birds.

Question 35

What are the 4 species of Mycoplasma?

Answer 35

- M. pneumoniae (Primary atypical pneumonia) - M.genitalium, M. hominis & Ureaplasma urealyticum (These last 3 cause Genitourinary tract infections) * Some mycoplasmas are part of the normal human flora.

Question 36

What are the reservoirs of M. Pneumoniae?

Answer 36

Humans only!

Question 37

What is "walking pneumonia"?

Answer 37

Primary atypical pneumonia, not cleared by penicillin.

Question 38

How is M.Pneumonia transmitted and where does it infect?

Answer 38

- Transmitted by respiratory droplets. | - Adhere to respiratory epithelium.

Question 39

The main cells of the inflammatory response associated with M. Pneumonia are ________.

Answer 39

Lymphocytes

Question 40

True or false, M.Pneumonia is highly destructive to tissues....(body tissues not kleenex)

Answer 40

False! However it does impair ciliary function.

Question 41

What "other" damage can M.pneumonia do?

Answer 41

- Hemolytic anemia = detectable in 50% of cases. - Encephalitis - Erythema multiforme (rash)

Question 42

_______ is the newest emerging human pathogen.

Answer 42

M. Genitalium (a lot like M. Pneumoniae)

Question 43

______ & _______ are frequently associated with diseases in newborns (commonly found in the respiratory tract and genitourinary tracts)

Answer 43

M. Hominis & U. Urealyticum | * can be isolated from the spinal fluid of newborns, yet don't always cause disease.