borrelia class
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Borrelia
Order: SpirochaetalesFamily:: Spirochaetaceae
Genus:: Treponema Borrelia
Family: LeptospiraceaeGenus:: Leptospira
General Overview
• Gram-negative spirochetes
• Spirochete from Greek for “coiled hair”
• Extremely thin and can be very long
• Tightly coiled helical cells with tapered ends
• Motile by periplasmic flagella (endoflagella)
Endoflagella
Borrelia
• Large, 5-30 um long & 0.3-.7 um wide
• Motile with endoflagella
• Readily stained by ordinary methods – Gram negative
• Irregular, wide open coils.
• Commensals in buccal & genital mucosa
Treponema Leptospira
Borrelia
Spirochaetales Associated Human Diseases
Genus Species Disease
Treponema pallidum ssp. pallidum
pallidum ssp. endemicum
pallidum ssp. pertenue
carateum
Syphilis
Bejel
Yaws
Pinta
Borrelia burgdorferi
recurrentis
Many species
vincenti
Lyme disease (borreliosis)
Epidemic relapsing fever
Endemic relapsing fever
Vincent’s angina
Leptospira interrogans Leptospirosis
(Weil’s Disease)
Lyme Disease
History
• Lyme, Connecticut, USA. – in 1975
• In a cluster of suspected Juvenile Rheumatoid
arthritis.
• Five years later, Burgdoofer identified the
organism.
Epidemiology
Causative organism: B.burgdorferi
Vector : Ixodid ticks
Reservoir: Deer &
small mammals
Morphology
• 4-5 * 0.2-0.25 um
• Flexible, helical
• Gram negative
Species
• B.burgdorferi
• B.garinii
• B.afzelii
Culture
• Fastidious
• Modified Kelly’s (BSK) medium
• Incubation at 33 degree for > 2 wks.
Clinical features
• Incubation period: 3-30 days
• Three stages
1. Erythema migrans
2. Disseminated infection
3. Persistent infection
Erythema migrans
1.ERYTHEMA MIGRANS
• Localised infection
• Expanding annular skin lesion
• Bull’s eye appearance.
1.ERYTHEMA MIGRANS
2. DISSEMINATED INFECTION
• Fever
• Headache
• Myalgia
• Arthralgia
• Lymphadenopathy
• Meningeal & Cardiac involvement
3. PERSISTENT INFECTION
• Chronic arthritis
• Polyneuropathy
• Encephalopathy
• Acrodermatitis
Lab Diagnosis
1. Isolation
1. Ticks
2. Patients – Skin, CSF & Blood
2. Serology
1. ELISA
2. IF
Treatment
• Doxycycline
• Amoxycillin
• Cefuroxime
Relapsing fever
Introduction
• Arthropod-borne infection
• Two types
1. Epidemic RF
2. Endemic RF
Epidemic RF
• B.recurrentis
• Louse-borne
• Pediculus humanus corporis (body lice)
• No extra-human reservoir.
Endemic RF
Causative agents:
1. B.duttonii
2. B.hermsii
3. B.parkeri
• Tick-borne
• Reservoir – Rodents & other mammals
Morphology
• 8-20 um * 0.2-0.4 um
• Irregular spirals with one or both ends pointed
• 5-10 loose spiral coils
• Gram negative
• Giemsa staining
Cultural characteristics• Microaerophilic
• Cultivation is difficult in medias
• Egg inoculation in chick embryos
• Chorioallantoic membrane
• Animal inoculation - intraperitoneal
• Rat
•Mice
Antigenic variation
• Readily undergoes antigenic variations in vivo
• DNA rearrangement in linear plasmids
• Ultimate recovery – development of immunity
to all the antigenic variants.
Clinical features
• Incubation period: 2-10 days
Sudden onset of fever (3-5 days)
Afebrile period for 4-10 days
Another bout of fever
• Subsides after 3-10 relapses.
Relapsing fever
Epidemiology- Epidemic Relapsing Fever
• Transmitted person-to-person by human body lice
(vectors) from infected human reservoir
• Infect host only when louse is injured, e.g., during
scratching
• A single louse can only infect a single person
• Lice leave host that develops a fever and seek
normal temperature host
Epidemiology- Endemic Relapsing Fever
• Sporadic cases
• Transmitted by soft body ticks (vectors) from
small mammal reservoir
• Ticks can multiply and infect new human
hosts
Lab Diagnosis
• Wet film
• Lashing motility
• Blood smears
•Giemsa stain
• Leishman stain
•Dilute carbol fuchsin
• During pyrexial period
Giemsa Stain of Borrelia recurrentis in Blood
Light Microscopy Phase Contrast Microscopy
Lab Diagnosis
• Animal inoculation
- White mice
- Intraperitoneal
• Serology
- Agglutinins for Proteus OXK
Treatment
• Tetracyclines
• Chloramphenicol
• Penicillin
• Erythromycin
Borrelia vincenti
• Fusospirochetosis
• B.vincenti
• Fusobacterium fusiforme
• Ulcerative gingivostomatitis
• Oropharyngitis (Vincent’s angina)
• Lung abscess
• Gangrenous balanitis
Vincent’s angina
Borrelia recurrentis
Borrelia spp.
Borrelia burgdorferi
Summary
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