Borrelia Burgdorferi

Question 1

Classification

Answer 1

Family: spirochaetaceae

Genus: Borrelia

Species: Burgdorferi

Question 2

Morphology

Answer 2

Spiral

Endoflagella

Highly motile

Question 3

Growth characteristics

Answer 3

Grows more readily in a complex liquid medium (Barbour-Stoenner-Kelly medium)

Question 4

Antigenic structure

Answer 4

Lipoproteins

Question 5

Virulence factors

Answer 5

Use of manganese instead of iron circumvents host defense

Avoid immune detection by altering membrane proteins

Question 6

Disease

Answer 6

Lyme disease

1st: unique skin lesion —> erythema chronicum migrans (ECM)
2nd: neurological, cardiac and/or arthritic complications may occur weeks to months later
3rd: chronic skin lesions (ACA) and damaged nervous system or joints are late manifestation

Question 7

Microbiological diagnosis

Answer 7

DME:

• dark field microscopy: large, loosely coiled motile spirals
• silver impregnation or Giemsa stains
• IFA

Cultures:
A modified Kelly’s medium is used, but the yield is low

Serologic tests:

• ELISA
• IFA
• Western Blot Assay
• PCR

Question 8

Treatment and prevention

Answer 8

• tetracycline and penicillin are recommended
• ceftriaxone may be effective
• no immunization