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Flashcards in Exotic Pulmonary Pathogens Deck (51)
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1
Q

What are the Gram staining and cell characteristics of Bacillus anthracis?

A

Gram +, large non-motile rod with square ends (box car is the buzzword)

2
Q

What are the virulence factors of Bacillus anthracis?

A

Capsule composed of D-glutamate (unique) and anthrax toxins –> also forms spores

3
Q

How is Bacillus anthracis transmitted?

A

Cutaneous contact; can be aerosolized droplets that cause pneumonic disease

4
Q

What are the 3 toxins produced by Bacillus anthracis?

A

Lethal factor –> cleaves host MAP kinases

Edema factor –> interferes with immune response

Protective antigen –> facilitates entry of lethal factor and edema factor into host cells

5
Q

What are the clinical findings in Bacillus anthracis pneumonic disease (brucellosis or Malta fever)?

A

Onset 4-6 days

Sudden high fever, chills, profuse sweating, dyspnea, hypoxia, and tachycardia

6
Q

What is seen on CXR with Bacillus anthracis?

A

Widened mediastinum with infiltrates and pleural effusions

7
Q

How is Bacillus anthracis diagnosed?

A

1) CXR or CT
2) Can culture blood or sputum
3) Measure antibodies or toxins in blood

8
Q

How do you treat Bacillus anthracis infection?

A

Ciprofloxacin for 60 days (dormant spores in macrophages) If severe, IV cipro + a penicillin or cephalosporin

9
Q

What are the Gram staining and cell characteristics of Brucella spp.?

A

Small Gram negative coccobacillus –>intracellular bacterium (no capsule)

10
Q

How is Brucella spp. infection usually contracted?

A

1) Contaminated dairy products
2) Direct contact with secretions of infected animals

11
Q

What are the pathogenic mechanisms of Brucella spp.?

A

Live inside macrophages and illicit granuloma formation with giant cells –> endotoxin (LPS)

12
Q

What are the clinical findings in Brucella spp.?

A

1) Fever, chills, fatigue, malaise, anorexia, weight loss
2) Enlarged lymph nodes, spleen, and liver
3) Pancytopenia
4) Large lung nodules on CXR

13
Q

How is Brucella spp. diagnosed?

A

1) Culture in enriched media and 10% CO2 (not common)
2) Rise in antibody titer of at least 1:160 (best diagnostic)

14
Q

How is Brucella spp. treated?

A

Tetracycline or doxycycline + rifampin

15
Q

What are the Gram staining and cell characteristics of Burkholderia pseudomallei?

A

Gram negative rod; facultative intracellular bacterium

16
Q

How is Burkholderia pseudomallei infection acquired?

A

Inhalation of aerosolized bacteria; typically after storms where bacteria in soil are aerosolized

17
Q

What are the pathogenic mechanisms of Burkholderia pseudomallei infection?

A

1) Capsule
2) Can mediate host cell lysis to infect other cells
3) Can use actin network to propel itself into adjacent cells
4) Can remain dormant in host for years

18
Q

What are the clinical findings of Burkholderia pseudomallei infection?

A

High fever, headache, anorexia, general muscle soreness, chest pain, cough

CXR shows small nodules and consolidation in upper lobes

19
Q

What are the diagnostic tests for Burkholderia pseudomallei infection?

A

1) Culture from blood, urine, or sputum
2) Measuring specific antibodies

20
Q

How is Burkholderia pseudomallei infection treated?

A

8 week course of ceftazidime –> 6 months if pt is immunosuppresed

21
Q

What are the names of the disease caused by Burkholderia pseudomallei infection?

A

Meliodosis or Whoitmore’s disease

22
Q

What is the name of the disease caused by Coxiella brunetii infection?

A

Q-fever

23
Q

What are the Gram staining and cell characteristics of Coxiella brunetii?

A

Gram negative bacillus; obligate intracellular parasite

24
Q

How is Coxiella brunetii infection spread?

A

1) Found in sheep, cattle, and goats; transmitted to humans that handle contaminated viscera or drink contaminated milk
2) Infected tick bite
3) Aerosolized spores (most serious form)

25
Q

What is the pathogenic mechanism of Coxiella brunetii infection?

A

Obligate intracellular parasite –> evades humoral defenses

26
Q

What are the clinical findings of Coxiella brunetii infection?

A

30-50% are asymptomatic Atypical pneumonia lasting 2-4 weeks –> sometimes has liver and heart involvement

27
Q

What diagnostic tests are used for Coxiella brunetii?

A

Serological –> looking for high antibody titers to Q-fever antigen

28
Q

How is Coxiella brunetii infection treated?

A

Most resolve spontaneously, but doxycycline can shorten duration

29
Q

What are the Gram staining and cell characteristics of Francisella tularensis?

A

small pleomorphic Gram negative rod; obligate intracellular bacterium

30
Q

What are the virulence factors of Francisella tularensis?

A

1) Atypical lipopolysaccharide that is not recognized by TLR-4
2) May produce capsule

31
Q

How is Francisella tularensis transmitted?

A

1) Tick bite, or blood-to-blood contact with infected animal (think hunters in Arkansas)
2) Aerosolized droplets
3) Ingestion in food or water

32
Q

What are the clinical findings of Francisella tularensis infection (tularemia)?

A

1) Sudden onset of flu-like symptoms
2) Regional lymph nodes become painful and swollen
3) CXR shows spotted infiltrates, lobar pneumonia, and pleural exudation

33
Q

What diagnostic tests are used for Francisella tularensis infection?

A

1) Agglutination tests
2) Fluorescent antibody staining of infected tissue

34
Q

How is Francisella tularensis infection treated?

A

Streptomycin

35
Q

What are the characteristics of the hantavirus?

A

1) Enveloped
2) Segmented
3) Single-stranded (-) sense RNA virus

36
Q

What is the epidemiology of hantavirus infection?

A

Mostly in young healthy adults that go camping and shit

37
Q

What disease is caused by hantavirus infection?

A

Hantavirus pulmonary syndrome

38
Q

How is hantavirus transmitted to humans?

A

Aerosolized rat excreta…

39
Q

What are the clinical findings of hantavirus pulmonary syndrome?

A

Flu-like symptoms and myalgia of large muscle groups that rapidly progress to interstitial pulmonary edema and respiratory failure… silly little viruses

40
Q

What are the CXR findings in hantavirus pulmonary syndrome?

A

1) Bilateral interstitial and alveolar infiltrates
2) Pleural effusion
3) Normal heart size

41
Q

How is hantavirus pulmonary syndrome treated?

A

1) Early, aggressive intensive care
2) Assisted ventilation
3) Maintaining electrolyte balance

42
Q

What are the Gram staining and cell characteristics of Yersinia pestis?

A

Small Gram negative encapsulated rod

43
Q

What are the unique staining characteristics of Yersinia pestis?

A

Bipolar staining –> resembles a safety pin (Step 1 buzzword)

44
Q

What disease is caused by Yersinia pestis infection?

A

THE PLAGUE or black death

45
Q

How is Yersinia pestis transmitted to humans?

A

Bitten by flea that has bitten infected rodent

Can also transmit from another person through aerosolized droplets (most fatal form)

46
Q

What is seen on CXR with Yersinia pestis infection?

A

Effects lower lung zones with bilateral pleural effusions

47
Q

What are the pathogenic mechanisms of Yersinia pestis?

A

Spreads regional lymph nodes –> very swollen and tender (called buboes) and can disseminate

48
Q

What are the virulence factors of Yersinia pestis?

A

1) Caps
2) Endotoxin (LPS)
3) V & W antigens allow intra-macrophage survival
4) Yersinia outer proteins injected by Type III secretion system prevent phagocytosis and cytokine production
5) Exotoxin

49
Q

What are the clinical findings of Yersinia pestis infection?

A

High fever, myalgia, extreme fatigue/collapse

Septic shock and pneumonia

50
Q

What diagnostic tests are used for Yersinia pestis?

A

1) Culture of blood or pus
2) Giemsa or Wayson stain –> safety pin appearance
3) Fluorescent antibody staining

51
Q

How is Yersinia pestis infection treated?

A

Streptomycin and tetracycline