Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MI Immuno/Heme > Bacterial blood infections > Flashcards

Bacterial blood infections Flashcards

1
Q

Basic characteristics of Rickettsia

A

-Obligate intracellular bacteria

Aerobic gram (-) rods

LPS has weak endotoxin activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Bacteria responsible for Rock Mountain spotted fever

A

Rickettsia rickettsii

Rickettsia parkeri (particularly in western US)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Rickettsia in the typhus group

A

Rickettsia prowazekii

Rickettsia typhi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How do Rickettsia escape the phagosome

A

Using phospholipase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Where do Rickettsia grow/replicate

A

In the cytoplasm/nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How are Rickettsia energy parasites?

A

THey have transporters that exchange ADP for host ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What Rickettsia lyse their host cell?

A

Members of the typhus group

R. prowazekii and R. typhi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What leads to reduced platelet count and increased coagulation time in Pt’s infected with Rickettsia?

A

Rickettsia induced oxidative damage to endothelium and vascular smooth muscle leads to platelet adherence

Platelets ares pulled out of circulation - leads to reduced count and increased coagulation time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What causes microthrombi in Pt’s w/ Rickettsia infection?

A

Damaged endothelial cells w/ their adherent platelets can be released into circulation - causing blockages in vasculature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Rickettsia rickettsii

A

Rocky mountain spotted fever

Vector: hard ticks

Dermacentor andersoni (wood tick) in Rocky Mountain states

Dermacentor variabilis (dog tick) in SE US and West Coast

Incubation - ~7 days (range: 2-14 days)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Rash in rocky mountain spotted fever

A

Usually begins as a maculopapular rash that progress to a petechial rash

Develops 2-5 days after exposure in 90% of cases

Initially seen on extremities and spreads to trunk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is indicative of a poor prognosis in Rocky Mountain Spotted fever?

A

Absent or late developing rash

Death in 20-40% w/o Tx or misDx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does the spotted fever group of Rickettsia exit the cell?

A

Utilizing actin polymerization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How does the typhus group of Rickettsia exit the host cell?

A

By lysing the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where does the RMSF rash present?

A

Petechial rash on the extrimities (includes soles and palms)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Resevoir Rickettsia prowazekii

A

Humans

Vector in US is flying squirrel fleas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Rash presentation w/ Rickettsia typhi and Rickettsia prowazekii

A

Rickettsia Prowazekii - rash presents initially (rash only in ~50% of cases) on chest/Abdomen before spreading to extrimities (oppositie w/ Rickettsia that causes RMSF)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Organism responsible for epidemic typhus

A

Rickettsia prowazekii

More severe disease than Rickettsia typhi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What cells does Ehrlichia infect?

A

Monocytes and tissue phagocytes (including spleen, liver, and lymph nodes)

Disrupts monocytes Fx and regulation of the inflammatory response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Anaplasma vector and resevoir

A

Vector = Ixodes ticks

Resevoir = small mammals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Erlichia vector and resevoir

A

Vector = Amblyomma americanum (Lone star tick)

Resevoir = white-tailed deer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What type of host cells does Erlicihia ewingii and Anaplasma phagocytophilum infection?

A

They intracellularly infect granulocytes

Pathology is related to macrophage activation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What type of bacterial morphology is characteristic of Borrelia

A

Gram (-) spirochetes

Extracellular frank pathogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Organism responsible for epidemic relapsing fever

A

Borrelia recurrentis - louse-borne

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Organism responsible for endemic relapsing fever

A

Many species of tick-borne Borrelia

26
Q

Virulence factors of Borrelia

A
27
Q
A

Eschar - seen in soft-body tick bite spreading endemic Borrelia

28
Q

Jarish-Herxheimer Rx’n

A

Shock-like sxs after initiation of Abx therapy for spirochete infection (killing intracellular bacteria in RBCs causing them to lyse and release inflammatory molecules)

29
Q

Bartonella characteristics

A

Gram (-), short, aerobic rods

Fastidious requirements

30
Q

What Pt’s are prone to bacillary angiomatosis by Bartonella henselae?

A

HIV Pt’s

Tx w/ azithromycin in immunocompromised Pt’s

31
Q

What causes Yersinia pestis to upregulate virulence factors upon entering its definitive host?

A

Increased temperature from flea to human

32
Q

What type of bacterial capsule does Yersinia pestis have?

A

Protein capsule - F1 antigen

Resists phagocytosis by macrophages

33
Q

When does a Yersinia infected Pt become contagious?

A

When the bacteria spreads to the lungs (Pneumonic plague)

34
Q
A

Yersinia pestis (characteristic gram-negative with a bipolar, or “safety pin” appearance, with Gram/Giemsa stain)

35
Q

Tx for Yersinia pestis

A

Aminoglycosides (streptomycin/gentamicin)

36
Q

Salmonella typhi

A

Gram (-) rod

Encapsulated w/ Vi antigen

Resistant to bile salts

Low infectious dose <1000 bacteria

37
Q

Salmonella typhi virulence and pathenogenesis

A
38
Q

Abx to Tx typhoid fever

A

Ceftriaxone
Azithromycin

Salmonella typhi has high levels of Abx resistance and must test to determine its presence

Cipro used to be first-line Tx, but is becoming less effective

39
Q

Only spirochete disease dx’d by microscopic demonstration of spirochetes in peripheral blood?

A

Endemic relapsing fever (Borrelia infection)

40
Q

Which of the following bacteria cause an infection that spreads from an initial papule to the regional lymph node causing significant lymphadenopathy in immunocompetent patients following a cat bite?

A

Bartonella henselae

41
Q

Which of the following bacteria are transmitted by body lice? (Select all correct answers)

A

Rickettsia prowazekii

Borrelia recurrentis

42
Q

Which of the following structures provides spirochetes with their characteristic motility?

A

Periplasmic flagella

43
Q

A 13-year-old migrant from Somalia, presents at a hospital in Italy with a high fever, headache, and general malaise. He notes that he first experienced these symptoms a few weeks ago while living in a refugee camp in Libya. He states that he has a high fever for a few days and then it goes away for a few days before returning again. A blood smear was negative for Plasmodium spp., but a Giemsa-stained blood smear was positive for many helical bacteria. Which of the following virulence determinants contribute to the clinical presentation caused by this pathogen?

A

Antigenic variation

Relapsing fever = Borrelia infection

44
Q

Borrelia recurrentis is spread by what vector?

A

Body lice

Epidemic relapsing fever

45
Q

Stain to ID Borrelia

A

Giemsa and Wright stain

46
Q

What vector transmits the pathogen responisble for endemic relapsing fever?

A

Soft-bodied ticks (quickly feed ~20 min)

Transmits Borrelia hermsii (and other Borrelia sp. responsible for endemic relapsing fever)

47
Q

What Borrelia infection occurs most commonly in the US?

A

Endemic relapsing fever

Borrelia recurrentis is responsible for epidemic relapsing fever (the other relapsing fever, more severe disease)

48
Q

Incubation of relapsing fever

A

Borrelia = infectious organism

49
Q

Vector for Rikettsia prowlezecki

A

Body lice

Epidemic typhus

50
Q

On July 30, a 54-year-old man became ill with fever, headache, arthralgia, myalgia, and nausea while vacationing at the Wild Horse Island, Montana. Two days later he visited the emergency room of a local hospital, but a diagnosis was not made. Over the next several days he improved, and on August 6, he and his family began driving back to their home in Seattle, Washington. During the trip, he experienced another febrile episode. That evening, he was taken to the emergency room of a Seattle hospital where he was diagnosed with relapsing fever. Which of the following was likely the source of his infection?

A

Relapsing fever caused by Borrelia and transmitted by a soft-bodied tick

Soft-bodied ticks located in the western US

51
Q

Distrubition, vector, and resevoir of Yersinia pestis in US

A

Vector = rodent fleas

Resevoir = prairie dogs (gophers) in US and rodents

52
Q

Yersinia pestis - pre-inflammatory vs. inflammatory stages

A
53
Q

Virulence factors of Yersinia pestis

A

-Plasminogen activator protease

-Type III secretion

-Lipid A modification

-Protein capsule

-Environmental sensing and regulation of virulence

54
Q

Clinical presentations of Yersinia pestis

A
55
Q
A

B. Disruption of protein synthesis by binding to the 30S ribosomal subunit

MOA of aminoglycosides (i.e. gentamicin)

56
Q

Highest burden of typhoid fever is endemic to?

A

India Subcontinent

China

SE Asia

Africa

57
Q

Virulence of Salmonella typhi

A
58
Q

Pathogenesis of Salmonella typhi

A
59
Q

Rose spots are characteristic of what type of bacterial infection?

A

Salmonella typhi - rose spots (groups of blanching papules on abdomen and sometimes posterior neck)

60
Q
A

C. Ingestion of contaminated food

Typhoid fever caused by Salmonella typhi

61
Q
A

C. Ehrlichia chafeensis

In Anaplasma - morulea are present in neutrophils and other granulocytes

MI Immuno/Heme (35 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions