Lecture 28 - Rickettsiales Flashcards

1
Q

What type of pathogen is Rickettsiales?

A

Obiligate intracellular parasites

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

What animals do Rickettsiales prefer?

A

Vertebrates + Arthropods + pretty much all eukaryotes

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

What part of the Rickettsiales’ life cycle do ticks blood-feeding arthropod play?

A

Host
– and –
Vector

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

What is one of the most important reservoir host for Rickettsiales?

A

Ticks

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

What kind of host are humans in the Rickettsiales life cyle?

A

Accidental

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

What are the genera of Rickettsiales that we are concerned with?

A

Rickettsia + Anaplasma + Erlichia

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

How does rickettsia differ from anaplasma and erlichia?

A

Erlichia + Anaplasma are both in the family Anaplsmatacaea

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

What are the structural characteristics of Rickettsiaceae?

A

Gram- negative

Pleomorphic coccobacilli

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

How do Rickettsiaceae enter the host cell?

A

Induces phagocytosis
Escapes phagosome
Grows in cytoplasm and/or nucleus

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

What cell type does Rickettsiaceae prefer to invade and grow?

A

Endothelial cells

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

What happens when Rickettsiaceae takes up residence in the endothelial cells?

A

Necortizing vasculitis

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

What are the downstream effects of necrotizing vasculitis?

A

Increased vascular permeability
– leading to –
Edema + Hemorrhage + Hypovolemia

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

What are the major clinical problems seen with a Rickettsiaceae infection?

A

Encephalitis + Nephritis + Myocarditis

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

What disease does Rickettsia rickettsii cause?

A

Rocky mountain spotted fever

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

What ticks commonly carry Rickettsia rickettsii ?

A

American dog
Brown dog
Rocky mountain wood

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

What tick is present in AZ that carries Rickettsia rickettsii ?

A

Brown dog tick

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

When in the US are the most cases in dogs of RMSF seen?

A

March to October

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

How old are most dogs that come down with RMSF?

A

less than 3 years old

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

What parts of the US most commonly have RMSF?

A

South central + Southeastern

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

What are the mammalian reservoirs for Rickettsia rickettsii ?

A

Wild rodents + other small mammals

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

What are the early signs of Rickettsia rickettsii infection in a dog?

A

Fever + V/D + Achey + Edema + Coughing

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

What neurological disturbances are seen in dogs with Rickettsia rickettsii ?

A

Depression + Stupor + Ataxia + Tremors

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

What occurs in severe cases of Rickettsia rickettsii in dogs?

A

Acral necrosis

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

What is the treatment for Rickettsia rickettsii ?

A

Doxycycline
– or –
Tetracycline

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

When should treatment for Rickettsia rickettsii be started?

A

ASAP, do not wait for diagnostics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the structural characteristics of Anaplasmataceae?

A

Gram-negative

Pleomorphic coccobacilli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What types of cells do Anaplasmataceae bacterias tend to infect?

A

Ones of hematopoietic origin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the most common blood cell type that Anaplasmataceae grow in?

A

Leukocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Where do Anaplasmataceae multiply?

A

Within membrane-boudn structures called morulae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What are the three Anaplasmas that are important to us?

A

Marginale
Platys
Phagocytophilum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What does A. marginale like to infect?

A

RBC’s of ruminants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What does A. Platys like to infect?

A

Platelets of canids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is unique about A. Platys?

A

ONLY PATHOGEN TO INFECT PLATELETS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What does A. Phagocytophilus like to infect?

A

Granulocytes + Monocytes of mammals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What animals can be infected with A. Marginale?

A

Domestic + Wild ruminants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What disease does A. Marginale cause in cattle?

A

Bovine anaplasmosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Where in the US does A. Marginale tend to infect cattle?

A

Southeast
Midwest
Western mountain region
CA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is the presentation of A. Marginale in a cow that is

A

Subclinical infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is the presentation of A. Marginale in a cow that is 6m to 3 years old?

A

Serious illness possible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is the presentation of A. Marginale in a cow that is > 3 years old?

A

30 to 50% mortality rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What are the two vectors most commonly spreading A. Marginale?

A

Black horse fly (Blood-feeding flies)
– and –
Tick ( Demacentor spp.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What type of vector is the black horse fly?

A

Mechanical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is seen in cattle that survive a A. Marginale infection?

A

Chronic, lifelong subclinical infections (carrier state)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is the clinical presentation of A. Marginale in cattle?

A

Fever + Anemia + Icterus

Pregnant cows can abort

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What is another name for A. Marginale infection in cattle?

A

Yellow bag
– or –
Yellow fever

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What can be seen histologically that will hint at a A. Marginale infection?

A

Inclusion bodies in RBC’s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

When is the only time a blood smear is successful at diagnosing a A. Marginale infection?

A

Early in disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What is the antibiotic treatment for A. Marginale?

A

Tetracycline
– or –
Imidocarb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What happens with treatment in severe cases of A. Marginale ?

A

Blood transfusion

50
Q

What can be used to prevent A. Marginale infections?

A

No USDA approved Vxn

51
Q

What does A. Platys most commonly infect?

A

Dogs

52
Q

Where is A. Platys most commonly found?

A

All over the world

53
Q

What is main vector for A. Platys?

A

Brown dog tick

54
Q

What does A. Platys cause in dogs?

A

Infectious canine cyclic thrombocytopenia

55
Q

What is the platelet count in a dog with A. Platys induced ICCT?

A
56
Q

How oftens does A. Platys cycle in dogs?

A

every 1 to 2 weeks

57
Q

What are the signs a dog is infected with A. Platys?

A

Fever + Petechiae/Ecchymoses + Epistaxis + Uveitis

58
Q

What is used to diagnose A. Platys in dogs?

A

Morulae seen in stained platelets
hard to find even in acute disease
In-house ELISA test

59
Q

What is the treatment for A. Platys?

A

Doxycycline

60
Q

Where is A. phagocytophilum seen in the US?

A

Northeastern
North central
West coast

61
Q

What does A. phagocytophilum tend to infect?

A

Mammals, wide range

62
Q

What are the main mammal reserviors of A. phagocytophilum ?

A

Wild rodents

63
Q

What is the vector for A. phagocytophilum?

A

Blacklegged ticks

64
Q

What two animals see the most noticable diease with A. phagocytophilum infection?

A

Dogs
– and –
Horses

65
Q

What disease is seen in dogs and horses with A. phagocytophilum?

A

Canine/Equine

Granulocytic anaplasmosis

66
Q

What are the common signs of Canine Granulocytic anaplasmosis?

A

Fever + Lethargy + Anorexia + Lameness

67
Q

What are the common signs of Equine Granulocytic anaplasmosis?

A

Same as dog

+ Limb edema + Petechia + Icterus

68
Q

What is seen in cats with A. phagocytophilum ?

A

Asymptomatic

69
Q

What is ruminants are most affected by A. phagocytophilum ?

A

Sheep + Cattle

70
Q

What happens when sheep or cattle are infected with A. phagocytophilum ?

A

Tick-borne fever

71
Q

Where is tick-borne fever seen in the world?

A

Europe + S. Africa + India

NOT US

72
Q

What is seen in humans with A. phagocytophilum ?

A

Asymptomatic most of the time

73
Q

What are some methods to diagnose A. phagocytophilum ?

A

Morulae in stained neurophils - hard to find

In-house ELISA

74
Q

What is the treatment for A. phagocytophilum ?

A

Tetracyclines
Oxy - Horse + ruminants
Doxy - Dogs

75
Q

What are the three ehrlichia species that can affect dogs?

A

Chaggeensis
Canis
Ewingii

76
Q

What does E. Canis cause in dogs/

A

Canine monocytic ehrlichiosis

77
Q

Where is E. Canis seen?

A

Worldwide

78
Q

What mammals are infected by E. Canis ?

A

Dogs and other Canids

79
Q

What kind of hosts are Canids to E. Canis ?

A

Reservior host

80
Q

What is the main vector for E. Canis ?

A

Brown dog tick

81
Q

What animals can have rare infections of E. Canis?

A

Cats + Ruminants + Humans

82
Q

What does E. Ewingii cause in dogs?

A

Canine Granlocytic Ehrlichiosis

83
Q

Where is E. Ewingii found in the US?

A

Southeastern + South central

84
Q

What is the main reservoir host for E. Ewingii?

A

White-tailed deer

85
Q

What is the main vector for E. Ewingii?

A

Lone star tick

86
Q

What does E. chaffeensis cause in dogs?

A

Mild, unnamed ehrlichiosis in dogs

87
Q

Where is E. chaffeensis found in the US?

A

Southeaster + South central + Mid-Atlantic

88
Q

What is the main reservoir host for E. chaffeensis?

A

White-tailed deer

89
Q

What is the main vector of E. chaffeensis in the US?

A

Lone star tick

90
Q

What does E. canis have tropism for?

A

Monocytes + Macrophages

91
Q

What does E. Ewingii have tropism for?

A

Granulocytes

92
Q

What does E. chaffeensis have tropism for?

A

Monocytes

93
Q

What is seen with acute CME?

A

Fever + Lethargy + Anorexia + V/D

Lameness/Stiffness

94
Q

What happens if some dogs dont recover from acute CME?

A

Persistent subclinical infection occurs for months to years

95
Q

What is seen with persistent subclinical CME infection?

A

Intermittent fever + Mild thrombocytopenia + Anemia

96
Q

What happens if a dog doesn’t recover from persistent subclinical CME infection?

A

Chronic CME infection occurs

97
Q

What breed is most likely to get a Chronic CME infection?

A

German Shepherd

98
Q

What is seen in CGE that is different then CME?

A

Milder form

Stiff gait + Musculoskeletal problems

99
Q

What is seen with infections caused by E. Chaggeensis?

A

Mild signs - fever + Thrombocytopenia

100
Q

What is the problem with using blood smears to diagnosis different Ehrlichias?

A

hard to find

E. ewingii + A. phagocytophilium cannot be told apart

101
Q

What does ELISA in-house tests test for?

A

Ab’s to E. Canis + E. ewingii

But E. Chaffeensis may cross react

102
Q

What is the treatment for ehrlichia?

A

Tetracycline

103
Q

What is a Neorickettsia?

A

Obiligate intracellular symbiont of flukes

104
Q

What are the two species of Neorickettsia that we are concerned with?

A

N. Helminthoeca
– and –
N. Risticii

105
Q

What does N. Helminthoeca cause in dogs

A

Salmon poisoning disease

106
Q

What does N. Risticii cause?

A

Potomac horse fever

107
Q

What is the reservoir + host of N. Helminthoeca?

A

Intestinal fluke

108
Q

What is the name of the intestinal fluke that N. Helminthoeca resides?

A

Nanophyetus salmincola

109
Q

What does the adult stage of Nanophyetus salmincola infect?

A

Fish-eating mammals + birds

110
Q

What does the larval stage of Nanophyetus salmincola infect?

A

Fish

111
Q

Where are N. Helminthoeca infections most commonly seen?

A

Pacific northwest
– and –
Southern Brazil

112
Q

What does N. Helminthoeca infect in dogs?

A

Monocytes + Macrophages
Starts in small intestines
Spreads to visceral + somatic LN

113
Q

What are the symptoms of SPD?

A

Fever + nasal/ocular discharge + Weight loss + Depression

114
Q

what is the mortality rate of an untreated dog with SPD?

A

90%

115
Q

What is the treatment for SPD?

A

Parenteral oxytetracycline
– or –
Doxycycline

116
Q

What is the reservoir + vector for N. risticii?

A

Intestinal flukes of bats

larval stage with in mayflies

117
Q

Where is N. risticii found?

A

USA + Canada + S. America + Europe

118
Q

What does N. Risticii have trophism for?

A

Monocytes + Intestinal macrophages + Mast cells + Enterocytes

119
Q

What occurs when a horse is infected with Risticii?

A

Acute enterocolitis

Abortion

120
Q

What are the clinical symtoms of PHF?

A

Fever + Anorexia + Depression + Colic

121
Q

What happens in severe cases of PHF?

A

Sepsis + Dehydration

122
Q

What is the treatment for N. Risticii in horse?

A

Parenteral oxytetracycline