Small Gram-negative pathogens

Question 1

T/F. Chlamydiae has peptidoglycan (mureine) in its cell walls.

Answer 1

False.

Question 2

How small is Chlamydiae? What tool can you use to visualize them?

Answer 2

0.25um to 0.8um

Light microscope

Question 3

Chlamydiae are _____ intracellular pathogens that only grow ____(inside/outside) cells or on ___(live/dead) tissues.

Answer 3

obligate; inside; live

Question 4

Chlamydiae is called an “___ ___” because it depends on its host for ATP.

Answer 4

energy parasite

Question 5

Chlamydiae is ____ for some amino acids.

Answer 5

auxotrophic

Question 6

What are the four species of Chlamydiae?

Answer 6

C. trachomatis, C. pneumoniae, C. psittaci, and C. pecorum

Question 7

what is the leading cause of preventable blindness in the world?

Answer 7

Chlamydial infections

Question 8

What is the most common agent of sexually transmitted bacterial infections?

Answer 8

Chlamydial infections

Question 9

Chlamydial infections are spread by ____ or direct contact and infection occurs in ____ epithelial cells.

Answer 9

droplet; mucosal

Question 10

T/F. Chlamydiae is usually an invasive infection affecting the eyes, lungs and genitalia.

Answer 10

False. Chlamydiae infections are localized except for when it causes Lymphogranuloma venerum, which is invasive.

Question 11

What are the 4 F’s of the spread of chlamydiae?

Answer 11

Fingers
Flies
Fomites
Fornication

Question 12

T/F. Chlamydiae infections are usually asymptomatic in females.

Answer 12

True

Question 13

Chronic and repeat Chlamydial infections in females can cause ___ and/or ___ pregnancy.

Answer 13

sterility; ectopic

Question 14

Chlamydiae has acute and chronic phases where during the ___ period the organisms location is unknown.

Answer 14

silent

Question 15

T/F. Asymptomatic carriage results in the least damage and scarring.

Answer 15

False. It results in the MOST damage and scarring

Question 16

What two conditions can infant contract during the birthing process?

Answer 16

conjuctivitis and pneumonia

Question 17

What is the name of the extracellular transit form of chlamydiae?

Answer 17

elementary body (EB)

Question 18

What mechanism is used to internalize EBs into the host?

Answer 18

receptor-mediate endocytosis

Question 19

The EB modifies the endocytic vesicle by maintaining a pH above ___ and preventing the vesicle from fusing with ___.

Answer 19

6.2; lysosomes

Question 20

How are the endocytic vesicles carrying EB camouflaged?

Answer 20

vesicles are modified with host components (glycolipids)

Question 21

Infectious EBs change into larger intracellular active organisms known as ____ ____.

Answer 21

Reticular bodies (RB)

Question 22

What mechanism do RBs use to divide?

Answer 22

binary fission

Question 23

Eventually, the entire vacuole becomes filled with EBs derived from RBs to form a cytoplasmic ____.

Answer 23

inclusion

Question 24

The developmental cycle of chlamydiae is ___ (fast/slow) and takes - days.

Answer 24

slow; 2-3

Question 25

How do RBs take up nutrients from the host if they remain inside of the inclusion vacuole?

Answer 25

18 - 23 hollow tube-like structures (drinking straws) protrude from the bacterial cell cytoplasm into host cell cytoplasm

Question 26

A patient who presented with vision problems has been found to have inflammation of the conjuctiva and scarring of the cornea. What chlamydial infection is the culprit?

Answer 26

C. trachomatis

Question 27

T/F. Lymphogranuloma venerum is a STD.

Answer 27

True.

Question 28

What Chlamydial disease is more common in Africa, Asia, India and South America and is a systemic, invasive infection of the lymph nodes that drain the genital tract?

Answer 28

Lymphogranuloma venerum

Question 29

What is the most prevalent Chlamydial infection in the human population?

Answer 29

Chlamydophila pneumoniae

Question 30

Chlamydophila pneumoniae can be directly observed in 40-100% of patients with what condition?

Answer 30

atherosclerotic heart lesions

Question 31

What is targets by antimicrobials in Chlamydial infections? How long are antibiotics given?

Answer 31

metabolic active RB | Organisms grow slowly so maintain for long periods

Question 32

What are the four membrane layers needed to penetrate to get to Chlamydiae?

Answer 32

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

Question 33

T/F. Rickettsiae is a small, gram negative rod that stains well.

Answer 33

False. Rickettsiae does not stain well.

Question 34

Rickettsiae is an ___ intracelluar bacteria that can be transmitted from animals to humans in a process called ___.

Answer 34

obligate; zoonoses

Question 35

T/F. Rickettsiae is also a "energy parasite".

Answer 35

False. Rickettsiae can synthesize some of their own ATP and are capable of undergoing independent metabolism

Question 36

What disease does Rickettsiae cause?

Answer 36

Rocky Mountain Spotted Fever

Question 37

The main vector of Rickettsiae is a ___, which will carry the pathogen for ___(days, months, life).

Answer 37

tick; life

Question 38

What life stage does the tick become infected with R. rickettsii bacteria?

Answer 38

larva or nymph

Question 39

How is the bacterial infection passed on to the human?

Answer 39

as an adult tick during the blood meal

Question 40

How is the bacteria spread in humans?

Answer 40

via the bloodstream

Question 41

Rickettsia attach to ____ endothelial cells and induce endocytosis. Once inside they presumably lyse the phagosome (____) and enter the ____.

Answer 41

vascular; phospholipase; cytosol

Question 42

R. prowazekii exit by cell ___. R. rickettsii get extruded through projections called ____. R. tsutsugamushi exit by ___.

Answer 42

lysis; filopodia; budding

Question 43

____ ____ due to actin polymerization, bacterium using the host's actin to propel itself

Answer 43

Comet tail

Question 44

How do patients develop hemorrhagic spots?

Answer 44

lysis of cells results in leakage of blood (rash)

Question 45

R. prowazekii causes ___ fever, which is a ____ typhus transmitted by ___.

Answer 45

typhus; recrudescent; lice

Question 46

R. typhi is a more prevalent and widespread ___ typhus that is transmitted by ___ and their fleas.

Answer 46

murine; rats

Question 47

T/F. Orientia (rickettsia) tsutsugamushi has a scrub typhus with NO observed rash.

Answer 47

True.

Question 48

Ehrlichia is an obligate intracelluar bacterial transmitted by what tick?

Answer 48

lone star

Question 49

What cells types are affect by Ehrlichia?

Answer 49

monocytes and macrophages

Question 50

Ehrilichia develops within host cell vacuoles first as ___ cells (RC) and then as ___-___ cells (DC).

Answer 50

reticulate; dense-core

Question 51

why is diagnosis of rickettsiae problematic?

Answer 51

at first visit, fever or rash may not appear and patient may be unaware of tick bite. Handling is notoriously hazardous.

Question 52

What is the smallest organism capable of growth on cell-free media?

Answer 52

mycoplasma

Question 53

T/F. mycoplasma lack a cell wall and are not sensitive to penicillin

Answer 53

true.

Question 54

What do the cell membranes of Mycoplasma contain?

Answer 54

sterols

Question 55

T/F. Humans are the only reservoir for Mycoplasma pneumonia.

Answer 55

true.

Question 56

A patient is diagnosed with "walking pneumonia" which is not cleared by penicillin treatment. What is the cause of this disease?

Answer 56

Mycoplasma pneumoniae

Question 57

T/F. M. pneumonia penetrates the lung alveoli.

Answer 57

False. M. pneumonia causes bronchopneumonia.

Question 58

What is the main cell of the inflammatory response in a m. pneumoniae infection?

Answer 58

lymphocytes

Question 59

T/F. Ciliary function is impaired by m. pneumonia infections.

Answer 59

true

Question 60

In what condition do antibodies (IgM = cold hemagglutinins) cause RBC's to stick together?

Answer 60

Hemolytic anemia