Zoonotic Gram Negative Bacteria (Hull)

Front 1

The zoonotic bacteria are gram ______, and thus they (do/don't) have endotoxin (lipid A).

Back 1

gram negative bacteria, do have endotoxin (lipid A)

Front 2

What's the good news and bad news about these zoonotic infections?

Back 2

Good: They are relatively rare causes of disease in the US (except for Rocky Mountain Spotted Fever being the most common)
Bad: If your patient does indeed have one of these, you aren't going to be thinking about these infections first off the bat

Front 3

What 3 groups are the Rickettsia broken up into?

Back 3

Coxiella, Ehrlichia, and Rickettsia

Front 4

What is the causative agent of Rocky Mountain Spotted Fever? And where is this disease most common?

Back 4

Rickettsia rickettsii. Most common in the Appalachia, Piedmont area, and Oklahoma

Front 5

What is unique about the hemorrhagic skin lesions seen with Rocky Mountain Spotted Fever?

Back 5

They are all over the body, but moreso they are characteristically located on the palms of the hands and soles of the feet (one of the few bacteria that have this ability).

Front 6

What is the causative agent of Typhus fever?

Back 6

Rickettsia prowazekii

Front 7

What is the reservoir of rickettsia prowazekii (causes Typhus fever)? The vector?

Back 7

reservoir = humans
vector = body louse

Front 8

Why is Typhus fever a disease of war and famine?

Back 8

Because during these times, there are huge displacements of people forced to wear the same clothes for long periods of time (ie flee from their homes with nothing but the clothes on their back). The body louse loves to live in the seams and folds of clothing, and will spread quickly under such conditions. Also, when these people die (those infected), others around may steal their clothes, helping propagate the spread of infection

Front 9

What is the causative agent of Ehrlichiosis? And what is this becoming an increasingly recognized cause of?

Back 9

*Ehrlichia chafeensis
*FUO = Fever of unknown origin

Front 10

What happens to the body louse in Typhus fever that does not happen to the ticks that transmit Rocky Mountain Spotted Fever (Rickettsia rickettsii) or Ehrlichiosis (Ehrlichia chafeensis)?

Back 10

The body louse itself gets infected and dies, therefore it cannot transmit the agent transovarily, whereas the ticks that give the other two do NOT die, and CAN transmit transovarily to their progeny.

Front 11

With the 3 groups of Rickettsia, are the antibodies diagnostic? protective?

Back 11

YES, YES!!!! The antibodies are both diagnostic and protective. Usually though, you have to wait around to see the Ab titer rise, and when you want to know sooner you just do a PCR test for the diagnosis.

Front 12

What are the reservoirs of Rickettsia rickettsii (causes Rocky Mountain Spotted Fever)? Vectors?

Back 12

*Reservoirs - dogs, rodents
*Vectors - ticks

Front 13

What is the reservoir of Coxiella burnetti? Vector?

Back 13

*Reservoir - cattle mainly, sheeps, and goats too
*Vector - inhalation

Front 14

What is the causative agent of Q fever?

Back 14

Coxiella burnetti

Front 15

Why do we see a rise in Houston of Q fever around this time of the year?

Back 15

Because of the rodeo, and people inhaling the Coxiella burnetti from the cows/bulls at the rodeo

Front 16

Of the Rickettsia, which one causes a patchy pneumonia?

Back 16

Coxiella burnetti causes a patchy pneumonia, that is actuall pretty much self limiting (will cure itself)

Front 17

Infection from the zoonotics follows 3 scenarios...

Back 17

1) direct contact with infected animal
2) direct contact with infected animal products (ie milk, cheese, etc)
3) bite of an arthropod that has fed upon an infected animal

Front 18

How must you target the treatment of zoonotic infections and what is the only exception to this and why?

Back 18

No penicillin, because you MUST target intracellular parasites with your antibiotics, therefore you need antibiotics that cross the eukaryotic cell membrane. The exception is wit Pasteurella multocida which can happily live in the bloodstream and spread this way, and in this case you could use penicillin to treat.

Front 19

Which is the only zoonotic gram negative organism that isn't preferential to be an intracellular parasite?

Back 19

Pasteurella multocida

Front 20

Give two characteristics Brucella and Mycobacterium TB share in common?

Back 20

1) Both are facultative intracellular parasites
2) Produce antibody in both cases that is diagnostic, but NOT protective

Front 21

Describe the disease manifestation in Typhus fever

Back 21

Vasculitis that results in rash, involvement of all major organs with multiple organ failure, shock, death

Front 22

Describe the cycle of infection by the Rickettsia

Back 22

They absorb to cells and penetrate into the endothelial cells, where they start a cycle of proliferation, cel lysis, and reinfection of healthy cells; results in vasculitis, occlusion of small vessels, microthrombi, and microhemorrhages (from damaging the endothelium)

Front 23

What is the causative agent of Trench fever during WWI? And more recently, this has been implicated in endocarditis especially with homeless and malnourished persons

Back 23

Bartonella quintana

Front 24

What is a recognized agent in cat scratch disease? What another that is present in the oropharyngeal flora of cats?

Back 24

Bartonella henselae (agent causing cat scratch disease) also can get infection from cat licking an already open wound, and Pasteurella multocida is a major oropharyngeal flora of cats and implicated also in cat scratch (cats licking paws then scratching) and also in cat bites.

Front 25

Bartonella henselae causes characteristic skin lesions in AIDS pateints called...

Back 25

Bacillary angiomatosis - basically looks like a tumor full of blood vessel growth

Front 26

What are the reservoirs of Brucella?

Back 26

goat (main one from story he told of the British soldiers in Malta who got sick from goat milk), cows, pigs, and dogs

Front 27

Why/how does Brucella infection give an undulating fever?

Back 27

During periods of growth inside the macrophages, there is no fever and patient is fine, but when they lyse and break out of cells looking to reinfect get a rise in the fever again along with subsequent remission when they enter cells again

Front 28

What might you find in goat milk that can give you Malta fever?

Back 28

Brucella

Front 29

Why were ranchers in Wyoming pissed off at Yellowstone?

Back 29

Because the bison were carrying Brucella abortus, roamed out of the park, gave the disease to the ranchers' cattle, and the Brucella abortus in cattle causes fetal abortions (didn't have their calves).

Front 30

Why were some people with Brucella being sent to psychiatric wards?

Back 30

Because the symptoms with it are so broad and general, nothing really characteristic of Brucella (tough diagnosis to make... headache, depression, fatigue, malaise)

Front 31

How infectious are Brucella? Francisella tularensis?

Back 31

Both extremely infectious, takes only 10 bacteria to cause infection!

Front 32

Why are people concerned of Francisella tulaensis as a means for biological terrorism?

Back 32

Because it takes only 10 bacteria to infect (low infectious dose), and it has plague like symptoms (though fatality rate is much lower)

Front 33

Francisella tularensis causes...

Back 33

tularemia or rabbitt fever

Front 34

Why is an image of a hunter commonly depicted with Francisella tularensis infection?

Back 34

Because can contract the organism while skinning animal (may cut self and get the bacteria in their), or may get it on their hand then rub their eye (for oculoglandular presentation)

Front 35

What is the most common presentation of Francisella tularensis?

Back 35

ulceroglandular (ulcer with swollen nearest lymph node)