Gram Negative Bacteria (Exam 3)

Question 1

coxiella burnetti

Answer 1

Q fever (pneumonia plus hepatitis), animal reservoir is sheep/livestock

Question 2

rickettsia rickettsii

Answer 2

Rocky Mountain Spotted Fever; vector is ticks; rash on hands/feet, myalgias, headaches/fever –> coma and death

Question 3

rickettsia prowazekii

Answer 3

epidemic typhus (rash and fever), reservoir is the louse, defacates on skin and scratched into bite

Question 4

What disease in USA is similar to epidemic typhus in other countries

Answer 4

Brill-Zinsser, found in elderly, recurrence of dormant rickettsial infection

Question 5

What is the Weil Felix test?

Answer 5

Used to diagnose RMSF and Typhus. The principle is based on the cross reaction of antibodies against rickettsial antigens to the antigens of OX strains of Proteus vulgaris

Question 6

What two gram negative bacteria are obligate intracellular pathogens?

Answer 6

chlamydiae and rickettsiae

Question 7

What are the three main diseases caused by rickettsiae?

Answer 7

RMSF, Q Fever, Epidemic Typhus

Question 8

Rickettsiae usally infect ______ cells

Answer 8

endothelial cells

Question 9

What are the four main diseases caused by chlamydiae?

Answer 9

trachoma (genital tract infections, eye and respiratory infections), pneumonia, urethritis, PID (pelvic inflammatory diseases)

Question 10

Describe spread of chlamydiae infection in cells

Answer 10

Elementary bodies form in epithelial cell cytoplasm, forming inclusion bodies. EB–>Reticulate body–>EB and lyse the cell to enter another and reproduce; inclusion bodies used for diagnosis between types of chlamydiae

Question 11

What is Reiter’s syndrome, and what bacteria is it involved with?

Answer 11

autoimmune disease (arthritis, urethrtis) caused by antibodies against C. trachomatis that cross reacts with antigens present in cells of eyes, joints and urethra

Question 12

which chlamydia is involved with bird excrement?

Answer 12

chlamydophila psittaci

Question 13

What does legionella cause?

Answer 13

atypical pneumonia, bacteria is inhaled, endotoxins released

Question 14

What gram negative bacteria is able to grow on charcoal-yeast media supplemented with iron and cysteine

Answer 14

legionella

Question 15

How does legionella survive?

Answer 15

legionella ingested by macrophage
the phagosome will recruit ribosomes to the membrane so it looks like rough endoplasmic reticulum.
Now the phagosome will not fuse with the lysosome so it survives

Question 16

What are the three main types of mycoplasma? What diseases do they cause?

Answer 16

M. pneumoniae- atypical pneumonia
M. hominis- PID
M. urealyticum- urethritis

Question 17

What is the most unique characteristic of mycoplasma?

Answer 17

has no defined cell wall, has a cell membrane enriched with cholesterol like eukaryotes; smallest free living organism

Question 18

What media is used to grow mycoplasma? What does it look like hwne imaged?

Answer 18

Looks like a fried egg

Can grow slowly on agar and broth plates with media enriched with lipids/ cholesterol

Question 19

How does mycoplasma pneumoniae cause pneumonia?

Answer 19

Attaches to respiratory epithelium and destroys cilia, so that there is irritation and cough; also oxidative stress

Question 20

What bacteria cause atypical pneumonia?

Answer 20

M. pneumonia, chlamydia psittaci, legionella pneumophila

Question 21

Why is it called atypical pneumonia?

Answer 21

causitive agent is not strep or haemophilus, intensity is less sever, cannot be isolated in routine culture media

Question 22

What are three major kinds of spirochetes,and what diseases do they cause?

Answer 22

Treponema- STDs (syphillis)
Borrelia- lyme disease
Leptospira- leptospirosis

Question 23

What symptoms are indicative of borrelia burgdorferi?

Answer 23

lyme disease

• joint pain
• bell’s palsy (facial nerve palsy)
• arthritis, cardiac, neurologic pain

Question 24

erlichia caffeensis

Answer 24

infection of WBC characterized by mulberry shaped aggregates (morulae)

Question 25

bartonella henselae

Answer 25

cat scratch disease