Borrelia Flashcards
The genus Borrelia includes species causing:
_______(e.g., Borrelia recurrentis, Borrelia duttonii) and
_______(e.g., Borrelia burgdorferi).
relapsing fever
Lyme disease
• Helical rods, 8-30 um long and 0.2-0.5 um in diameter
• Antigenic (flagellum, binding/outer surface proteins, etc.) and genetic differences are used to differentiate species
Borrelia
Borrelia recurrentis
Vector:
Pediculus humanus
Borrelia recurrentis
Vector: Pediculus humanus
MORPHOLOGY/STAINING
CHARACTERISTICS:
• Wet preparations of peripheral blood
• Mixed with equal parts of sterile, nonbacteriostatic saline under dark- or bright-field illumination, in which the spirochetes move rapidly, often pushing the red blood cells around.
• Staining thick and thin films with_______(2) stains using procedures similar to those used to detect malaria.
Wright’s or Giemsa’s
Borrelia
Cultivation: Grown in_____ medium in clinical labs.
Kelly
Virulence Factors
• _______: Caused by antigenic variation, where Borrelia species alter surface antigens to evade the immune response, leading to recurring febrile episodes.
• _______: Borrelia burgdorferi binds plasminogen and factor H to evade complement and modulate immune responses, contributing to immune suppression.
Relapsing Fever
Lyme Disease
• Symptoms:
• Initial Phase: Sudden onset of fever, chills, headache, muscle aches, and weakness. The fever lasts 3-7 days, ending with an immune response.
• Relapse Phase: The fever recurs after a few days or weeks with similar but milder symptoms.
Relapsing fever
Transmission:
• Tick-borne: Transmitted by soft ticks (______).
• Louse-borne: Transmitted by the body louse (______), where infection occurs when lice are crushed into the skin.
Ornithodoros
Pediculus humanus
Lyme Disease
• Stages:
• Erythema migrans (EM), a red, expanding skin lesion at the tick bite site. • Constitutional symptoms: Fatigue, headache, fever.
Stage 1 (Localized)
Lyme Disease
• Stages:
• skin lesions, migratory joint pain, and neurological symptoms.
Stage 2 (Disseminated)
Lyme Disease
• Stages:
• Chronic arthritis, neurologic issues (e.g., Bell’s palsy), and musculoskeletal problems.
Stage 3 (Persistent Infection)
Relapsing Fever:
• Tick-borne: Found globally but varies by species and region.
• Louse-borne: Associated with poor hygiene and overcrowding, common in areas with epidemic outbreaks.
Lyme Disease:
• Transmission: From infected_____, with most cases occurring during outdoor activities in summer months.
• Geography: Found in North America, Europe, and Asia.
• Prevention: Wear protective clothing, use tick repellents, and remove ticks promptly
Ixodes ticks
RELAPSING FEVER
• Fever, rigors, headaches, myalgia, arthralgia, photophobia, cough;
skin rash may occur
•Fatal cases: involve CNS, spleen, liver, other organs, hemorrhagic lesions (kidneys and GIT)
• Ultimate recovery: after______ relapses
• Clearance:_____
3-10
antibody-mediated killing of spirochetes
- tickborne (Ornithodoros), zoonotic
B. duttoni
B. hermsii
B. parkeri
B. turicatae
B. miyamotoi
_______: Epidemic relapsing fever
• Definitive: Direct observation from blood specimens of febrile
patients (spirochaetemia)
• Darkfield (wet prep), move rapidly RBCs
• Thick & thin smear, Wright or
Giemsa stains, or acridine orange
• Serology not reliable;
ANTIGENIC SHIFTS
Borrelia recurrentis
Borrelia burgdorferi
Vector:
Ixodes tick
Borrelia burgdorferi
MORPHOLOGY/STAINING CHARACTERISTICS:
1. Tissue sections stained with:_____
2. Modified Kelly’s medium colonies stained with:______
3. Modified Kelly’s medium (BSK II, BSK-H, or Preac-Mursic)
Incubated at 30°C to 34°C for up to 12 weeks under microaerophilic
Warthin-Starry silver stain
Acridine orange
- sole cause of Lyme disease in the USA where Lyme arthritis is a common
complication of infection.
B. burgdorferi sensu stricto
- responsible for the Lyme disease in Europe and are associated with chronic skin and neurologic manifestations, respectively.
B. afzeli and B. garinii
B. afzeli and B. garinii vectors
Ixodes dammini
l. pacificus
I. ricinus
Borrelia may be grown on liquid medium:_______, seldom used
Barbour-Stoenner-Kelly (BSK II) medium
