Spirochetes I (Borrelia)

Question 1

What are the general characteristics of Spirochetes?

Answer 1

• Long, slender, spiral-shaped
• Gram negative
• Tightly coiled and look like miniature springs or telephone cords
• Motile - axial filaments similar to flagella
• Extracellular organisms

Question 2

How is the Membrane and Cell wall of Spirochetes different from regular Gram Negative bacteria?

Answer 2

Question 2

How is the Membrane and Cell wall of Spirochetes different from regular Gram Negative bacteria?

Answer 2

Question 3

How are Spirochetes Classified?

Answer 3

• Genus: Borrelia (8-16 mcm)
  
  • vector-borne (tick and louse)
  • 15-40 flagella
• Genus: Treponema (3-8 mcm)
  
  • T. pallidum, transmitted by close contact
• Genus: Leptospira (6-20 mcm)
  
  • Hooked end, pathogenic and free living
  • 2 flagella
• Genus: Brachyspira
  
  • 6-10 flagella

Question 4

What is the Pathogenesis of Spirochetes?

Answer 4

• Extracellular pathogens
  
  • Migrate from the site of infection to other parts of body via blood an lymph
• Antigenic variation
  
  • important method to evade host response

Question 5

How is a Spriochetes infection diagnosed?

Answer 5

• Clinical signs and case history
• Microscopy
  
  • Dark field
  • Fluorescent antibody
  • Giemsa or Wright’s stain
• Antibody tests
  
  • Western blot, ELISA
  • Paired serum sample analysis
    
    • acute and convalescent
• PCR

Question 6

How is a Spirochetes infection treated?

Answer 6

• Doxycycline
  
  • Drug of choice
• Penicillin
• Erythromycin
• Tetracycline

Question 7

What are the important diseases are caused by Spirochetes?

Answer 7

• Vector-borne diseases
  
  • Ticks
  • lice
• Lyme Disease
  
  • Human, Dogs, Horses, Cattle, Cats
• Avian Borreliosis
• Relapsing Fever - Humans

Question 8

What is the cause of Lyme Disease?

Answer 8

• Borrelia burgdorferi
• Transmitted by:
  
  • Ixodes scapularis
  • Ixodes pacificus

Question 9

What are the signs and symptoms of Lyme Disease?

Answer 9

• Tick Bite
• Clinical symptoms start ~7 days in humans
  
  • Fever
  • Malaise
  • Fatigue
  • Stiff neck
  • Headache
• “Bull’s eye” Rash
  
  • Erythema Migrans
  • Pathogen disseminates from the site of tick bite via lymphatic and blood circulation
• Arthritis:
  
  • Intermittent swelling and joint pain
  • Muscle pain and depression
• Neurological manifestations
  
  • Lymphocytic meningitis
  • Cranial neuropathy
  • Sleep disturbances
• RARELY fatal

Question 10

What animals can B. burgdorferi cause infections in ?

Answer 10

• Humans
• Dogs
• Cats
• Cattle
• Horses

Question 11

How does Lyme Disease affect Dogs?

Answer 11

• Loss of appetite and fever
  
  • 104 - 105F
• Lethargy
• “shifting lameness”
• Kidney damage
• Heart disorders
• Neurological symptoms
  
  • aggression
  • Delirium
  • Seizure

Question 12

How does Lyme disease affect Cats?

Answer 12

• Fever
• Loss of appetite
• Fatigue
• May show lameness
• Eye infection
• irregular breathing
• Some infected cats maybe asymptomatic

Question 13

How does Lyme Disease affect Cattle?

Answer 13

• Many do not show any visible clinical signs
• Fever
• Laminitis
• Weight Loss
• Lameness
• Swollen Joints
• Skin Rash may be present on the udder
• B. Burgdorgeri May be found in urine, colostrum, blood, milk, synovial fluid and in aborted fetal tissues

Question 14

How des Lyme Disease affect Horses?

Answer 14

• Mild to no fever
• May have lameness or stiff joints
• Laminitis
• depression
• Loss of appetite
• Blindness or partial loss of vision
• Abortion
• Neurological signs
  
  • Head tilt
  • Aimless wandering
  • encephalitis
• Transplacental transmission have been reported
  
  • Newborn colts my display birth defects

Question 15

How is Lyme disease Diagnosed?

Answer 15

• Tick bite and clinical signs
• PCR of skin biopsy
• culture?

Question 15

How is Lyme disease Diagnosed?

Answer 15

• Tick bite and clinical signs
• PCR of skin biopsy
• culture?

Question 16

How is Lyme Disease Treated?

Answer 16

• Doxycycline
• Erythromycin
• others

Question 17

What are the Prevention options for Lymes Disease?

Answer 17

• Vaccine - Lyme Bacterin

Question 18

What can be done to protect humans from ticks?

Answer 18

• Apply tick repellants
• Wear light-colored clothing
  
  • tuck pants into socks
• Conduct body search
• Remove ticks carefully
  
  • Never squeeze, crush, or puncture

Question 19

What is Avian Borreliosis (Fowl Spirochetosis) caused by?

Answer 19

• B. anserina
  
  • Transmitted by fowl tick (Argas Persicus)
• Affects Chickens, ducks, turkey, and geese

Question 20

What is Avian Borreliosis?

Answer 20

• B anserina can be isolated from the Blood, spleen, liver, intestine, and kidney
• Severe hemolytic disease
  
  • Septicemia
  • Fever
  • Diarrhea
  • Drowsiness
  • Emaciation

Question 21

What causes Tick-borne Relapsing Fever?

Answer 21

• B. hermsii
• B. turicatae
• B. parkeri
• several others

Question 22

That happens during Relapsing Fever?

Answer 22

• Tick-borne or Louse-borne
• Recurrence of elevated temperatures and flue like symptoms every few days
• Pathogen changes surface proteins to stay ahead of antibodies

Question 23

What is Treponema pallidum?

Answer 23

• Causative agent of syphilis
• Mode: sexual contact
• Infection: site of infection and spreads to other organs
  
  • Can damage:
    
    • Brain / nerves
    • eyes
    • heart / blood vessels
    • Liver
    • Bones / joints
• Lesion:
  
  • Primary, Secondary, and Tertiary
• Treatment: Penicillin