Final; Small Gram-Negative Pathogens

Question 1

This is an obligate intracellular pathogen growing only inside cells or on live tissues and depend on their host for ATP

Answer 1

Chlamydiae

Question 2

What are the 4 recognized species of Chlamydiae

Answer 2

C. trachomatis
C. pneumoniae
C. psittaci
C. pecorum

Question 3

Chlamydiae is the leading cause of preventable what and the most common what

Answer 3

blindless

agents of sexually transmitted bacteria infections

Question 4

How is Chlamydiae spread

Answer 4

droplet or direct infection

4 F’s; fingers, flies, fomites, fornication

Question 5

Where does Chlamydiae infect

Answer 5

mucosal epithelial cells

localized; eyes, lungs, genitalia

Question 6

What are the symptoms of a Chlamydiae genital tract infection

Answer 6

males; prostitis, epididymitis
femalse; cervicitis, PID, premature birthda, pelvic pain, newborn infection
both; urethritis, infertility, proctitis, arthritis

Question 7

How is the disease manifested in females

Answer 7

usually asymptomatic in females; chronic or repeat infections can cause sterility and/or ectopic pregnancy

Question 8

What is characteristic of Chlamydiae infections

Answer 8

may be acute or chronic; silent period
asymptomatic carriage results in most damage and scarring
during birth, infants can contract the infection

Question 9

This is the non-replicating infectious particle that enters epithelial cells and is internalized by receptor-mediated endocytosis

Answer 9

elementary body

Question 10

The elementary body modifies the endocytic vesicle in which two ways

Answer 10

maintain pH above 6.2

prevents vesicle from fusion with lysosomes

Question 11

How is the vesicle modified by the host

Answer 11

modified with host glycolipids for camouflage

Question 12

What do the infectious EBs change into

Answer 12

larger intracellular active organisms called reticular bodies

Question 13

What do reticular bodies do within the vesicle

Answer 13

synthesize molecules using host metabolites and energy
divide by binary fission
organisms develop slowly (2-3 days per cycle)

Question 14

How do reticular bodies uptake nutrients

Answer 14

tube-like structures that allow them to feed on eukaryotic host cell without leaving the inclusion vacuole
18-23 tubes

Question 15

This is inflammation of the conjunctiva, can cause blindness and scarring of the cornea

Answer 15

trachoma (C. trachomitis)

Question 16

How is trachoma spread

Answer 16

by direct contact with yes, nose, and throat secretions from affected individuals or contact with objects such as towels or washcloths

Question 17

This is a STD, systemic invasive infection apparent in the lymph nodes that drain the genital tract found in developing countries

Answer 17

lymphogranuloma venerum

Question 18

This is the most prevalent chlamydial pathogen in the human population; 50% of people up to age 20% are infected and 80% of older adults

Answer 18

chlamydophila pneumoniae

Question 19

C. pneumoniae invokes what type of symptoms

Answer 19

asymptomatic or acute respiratory response but chronic respiratory infections have been associated with asthma, CF, and lunch cancer
directly observed in 40-100% of patients with atherosclerotic heart lesions

Question 20

What is the treatment for chlamydia

Answer 20

target the metabolically active RBs
there are four membrane laters to penetrate
organisms grow slow so the antibiotics must be taken for a longer period of time

Question 21

This is an obligate intracellular small gram-negative rod bacterium that can be spread from animals to humans (zoonoses)

Answer 21

rickettsiae

Question 22

What is the main difference between rickettsiae and chlamydia

Answer 22

rickettsiae can synthesize its own ATP and is capable of independent metabolism
it may lack certain metabolites necessary for growth
no flagella or endospores
must be cultivated in animals, embryonated eggs, or cell cultures in the lab

Question 23

What are some diseases caused by rickettsiae

Answer 23

rocky mountain spotted fever

typhus

Question 24

How is rickettsiae transmitted

Answer 24

only ticks are naturally infected
the ticks feed on large mammals and the larva/nymph feed on small rodents
the bacteria is spread through the blood stream

Question 25

How does rickettsiae spread and multiply

Answer 25

attaches to vascular endothelial cells; induces endocytosis | once inside, presumably lyse the phagosome (phospholipase) and enter the cytosol

Question 26

How does R. prowazekii exit the cell

Answer 26

lysis

Question 27

How does R. ricketttsii exit the cell

Answer 27

gets extruded from the cell through local projections (filopodia) actin helps to give it a push

Question 28

How does R. tsutsugamushi exit the cell

Answer 28

by budding through the cell membrane; will remain enveloped as it infects other cells

Question 29

What is the injury to the host as a result of Rickettsiae

Answer 29

it is proportional to the number of intracellular bacteria lysis of cells leads to rash; hemorrhagic spots it can travel to other vessels including heart and brain 75% of patients will clear before antimicrobial treatment

Question 30

This causes typhus fever, recrudescent typhus, and is transmitted by human lice the reservoir is humans and flying squirrels

Answer 30

R. prowazekii

Question 31

This is prevalent and widespread, marine typhus, and is transmitted by rats and rat fleas

Answer 31

R. typhii

Question 32

This causes scrub typhus, there is a variety of antigenic types but there is no rash as observed in the other

Answer 32

Orentia tsutsugamushi

Question 33

This is an obligate intracellular bacteria discovered in 1987 that infects mostly monocytes, macrophages, and neutrophils

Answer 33

Ehrlichia

Question 34

What are the disease/infections of ehrlichia

Answer 34

human granulocytic ehrlichiosis human monocytic ehrlichiosis causes fevers, malaise, headache, and myalgia

Question 35

Where does ehrlichia develop within the cells

Answer 35

within host cell vacuoles first as reticulate cells (RC) and then as dense-core cells (DC)

Question 36

Why is diagnosing rickettsiae problematic

Answer 36

during the fist visit patients may not be aware of tick bite or have a fever/rash required eukaryotic cell cultures or inoculation of animals handling is hazardous

Question 37

What are the clinical diagnosis tests for rickettsiae

Answer 37

antibody titer fluorescent antibody assay complement fixation latex agglutination

Question 38

This is the smallest organism capable of growth on cell-free media, its cells membranes contain sterols and is found in

Answer 38

mycoplasma

Question 39

What are some important characteristics of mycoplasma

Answer 39

``` *requires sterol characteristic "friend egg" appearance small colonies slow growth lack of cell wall; not sensitive to penicillin ```

Question 40

What are the four species of mycoplasma that causes disease

Answer 40

``` M. pneumoniae M. genitalium M. hominis Ureaplasma urealyticum some microplasms are part of microbiota ```

Question 41

Where is M. pneumonia encountered

Answer 41

humans are the only reservoir spread through close contact via respiratory droplets; mild to moderately contagious is adheres to respiratory epithelium

Question 42

M. pneumoniae is typicaly referred to as what

Answer 42

"walking pneumonia" primary atypical pneumonia; not cleared by penicillin

Question 43

Where does M. pneumonia infect

Answer 43

colliery function of the lungs is impaired it is largely limited to the respiratory mucosa that lines the airways doesn't get into lung alveoli; bronchopneumonia tissue toxin substances may include H2O2

Question 44

What are the main cells of the inflammatory response

Answer 44

lymphocytes

Question 45

What type of damage can M. pneumonia cause besides in the respiratory tract

Answer 45

``` hemolytic anemia; IgM = cold hemagglutinins, colder temps cause them to aggregate encephalitis erythema multiforme (rash) ```

Question 46

This is the newest emerging human pathogen causing urethritis, cervicitis, endometritis, and PID

Answer 46

M. genitalium

Question 47

These are frequently associated with diseases in newborns, commonly found in respiratory and genitourinary tract; and is present in most of the sexually active population

Answer 47

M. hominis and U. urealyticum

Question 48

True or False | M. hominis and U. urealyticum can be isolated from the spinal fluid of newborns, but always cause disease

Answer 48

False; it doesn't always cause disease