Micro of Zoonotic Skin Infections - Miller Flashcards Preview

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Flashcards in Micro of Zoonotic Skin Infections - Miller Deck (58):
1

Common symptoms of all zoonotic bacterial infections?

Flu like symptoms (myalgias, fever, malaise)

2

Morphology/gram stain of Rickettsia, Ehrlichia, and Coxiella? Do they gram stain well?

Short gram negative rods; all obligate intracellular parasites that express LPS. Do not gram stain well

3

Common pathogenesis of all Rickettsial microbes?

Vasculitis of the endothelial layer, causes a cutaneous rash. LPS mediates the fever/petichae

4

What organism causes RMSF?

Rickettsia Rickettsii

5

Vector that commonly transmits RMSF?

Dog ticks

6

What seasons and where are you most likely to get RMSF?

Spring and summer months; Georgia, North Carolina, and Virginia are the most common

7

Presentation of RMSF?

Typical flu like symptoms; muscle soreness in the CALVES; rash that STARTS AT THE ANKLES/WRISTS and proceeds proximally (this is pathognomonic); palms and soles are commonly involved (also specific for RMSF)

8

Severe complications of RMSF if untreated?

CNS change leading to delirium and coma; DIC with circulatory collapse

9

What test do you use to diagnose RMSF?

Weil-Felix Test

10

How does the Weil-Felix test work?

Uses antigens derived from Proteus; for some reason Rickettsial specific antibodies cross react with the antigens

11

What organism causes Epidemic Typhus?

Rickettsia Prowazekii (epidemic and Prowazekii both have "P's")

12

Presentation of epidemic typhus?

flu-like symptoms for 1-3 weeks; rash that spreads from the TRUNK-->distally to extremities (KNOW THIS); palms and soles are not involved with rash (KNOW THIS TOO)

13

Criteria for diagnosis of epidemic typhus?

When antibodies specific to Rickettsia Prowazekii increase 4x between acute-phase and convalescent serum

14

What causes Endemic typhus?

Rickettsia typhi

15

What vector transmits endemic typhus?

Fleas

16

Presentation of endemic typhus?

Significantly less severe disease that epidemic typhus

17

What 2 bugs cause Southern tick-borne disease?

Ehrlichia chaffeensis and Anaplasma phagocytophilia

18

What tick transmits anaplasmosis?

Ixodes ticks

19

What tick transmits ehrlichiosis?

Lone star deer tick (fucking Texas)

20

What is the specific name for the disease caused by Ehrlichiosis chaffeensis?

Human monocytic ehrlichiosis

21

Where specifically in the body does ehrlichiosis infect/replicate?

Monocytes; they're obligate intracellular parasites

22

Diagnosis of ehrlichiosis?

Blood smear looking for morulae in circulating monoctyes

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23

Unique symptoms to Ehrilichiosis?

N/V/D, cough, and CONJUNCTIVITIS 

24

What disease does anaplasma phagocytophilia cause?

Human granulocytic anaplasmosis; "Rocky Mountain Spotless Fever"

25

Why is human ganulocytic anaplasmosis referred to as Rocky Mountain Spotless Fever?

Because rash is uncommon

26

What does it indicate if there is a rash present in Rocky Mountain Spotless Fever?

Most likely coinfection with Borrelia Burgdorferi 

27

Diagnosis of Anaplasma phagocytophilia

Blood smear looking for mourlae in NEUTROPHILS

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28

Severe complications seen in Anaplasma phagocytophilia?

Renal failure and hemorrhage, respiratory compromise, CNS issues

29

Morphology of Coxiella Burnetti?

Gram-negative bacillus; obligate intracellular parasite

30

Primary carriers of Coxiella burnetti?

Sheep, Cattle, Goats

31

2 common ways Q- fever (coxiella burnetti) is contracted?

Ingestion of contaminated dairy products; contact with contamintated animal viscera (usually birthing of livestock)--> veternarians and farmers at risk

32

ID50 of Coxiella?

Less than 50; one of the most infectious human pathogens

33

Typical coure of Q-fever? What about more severe disease?

cutaneous disease with acute febrile illness with atypical PNA lasting 2-4 weeks; most serious disease causes endocarditis and granulomatous hepatitis

34

Describe spirochetes

Very flexible, highly motile; have a unique cork-screw-like appearance 

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35

What 2 species of spirochetes are we concerned with?

Borrelia and Leptospira interrogans 

36

What disase does borrelia burgdoferi cause?

Lyme Disease

37

Vector for lyme disease (borrelia) 

Ixodes tick 

38

Where and when would you get Lyme disease?

Summer months; Northeastern states and Wisconsin 

39

Diagnosis of borrelia?

Stain with Giesma or silver stain

40

Why is it important that the nymphal stage tick more commonly causes Lyme disease?

They're tiny so people don't notice them until they've been munching on them for a while

41

Generalized pathogenesis of Borrelia?

Bugs disseminate from the orignal vector bite through surrounding skin and into bloodstream; ensuing bacteremia allows dissemination to heart, the joints, CNS

42

Describe the 3 stages of disase in Lyme disease

Stage 1) Erythema chronicum migrans (charactersitic bullseye rash)

Stage 2) Cardiac and neurologic symptoms; Myocarditis with heart block; BILAT FACIAL NERVE PALSY (pathognomonic 

Stage 3) development of arthritis in large joints like the knees and shoudlers

43

Picture of erythema chronicum migrans

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44

Diagnosis of borrelia burgdorferi

Serology using ELISAs to measure IgM/IgG specific for Borrelia; confirm with a Western Blot for any + ELISA

45

What 2 species cause relapsing fever? What is their vector and where are they found?

Borrelia hermsii and Borrelia recurrentis; small rodents and endemic in the Western US

46

Clinical presentation of relapsing fever?

Fever that lasts for weeks, resolves, and reccurs with this continuing over 10 times

47

What do leptospira interrogans look like?

Tightly coiled spirochetes

48

What is the primary resovoir in the US for leptospira?

Dogs 

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49

Other common way to contract leptospira besides canine contact?

Consumption of contaminated water or swimming in contaminated water

50

Early symptoms of Leptospirosis?

Flu-like symptoms with conjuncitivits

51

Severe disease symptoms seen in Leptospirosis?

Liver damage (jaundice), Kidney dysfunction (uremia), Lung hemorrhage, Aspetic meningitis

52

What causes cat scratch disease?

Bartonella Heneslae

53

Where is bartonella found in the cat?

Normal oral flora

54

What 2 ways can you get catch scratch disease from a cat?

Scratches or bites; NOT from fecal matter

55

Clinical presentation of cat scratch disease?

Fever, tender/enlarged lymph nodes on the same side as the bite. Papule may occur at the bite site. Relatively benign disease

56

Cat scratch disease in AIDS pts?

Bacillary angiomas may form on the skin and visceral organs 

57

Diagnosis of bartonella heneslae?

Warthin-Starry stain

58

What disease must you r/o in a patient with bacillary angiomomatosis?

Kaposi Sarcoma (most common malignancy in AIDS pt)