1. GENUS BORRELIA Habitat
Spirochete
gram -
Giemsa or Wright’s stain are best
15-20 axial filaments
ferment glucose and other CHO
slow growing microaerophile
Habitat
obligate parasites in a variety of vertebrate hosts pathogenic borreliae of animal are vectored by ticks other arthropods are short term vectors

3. DISEASES
Relapsing fever
Lyme disease

4. Lyme Disease :
Transmitted by ticks (Ixodes spp.) aquired by larval stages of ticks feeding on small rodents and variety of small wild animal act as reservoir hosts does not undergo the antigenic changes of relapsing fever
B. burgdorferi (predominant in North America)
B. garinii
B. alfzelli etc

5. Virulence factor
Spirochaete are restricted to the mid gut
Following ingestion of blood , they are found in salivary gland
Following ingestion of blood by the ticks, a change occur in outer surface protein of borreliae (Osp) from OspA to OspC (essential for virulence)

6. Reservoir host
Maintenance host
Lyme disease
Incidental host

9. PATHOGENESIS Infected larva tick on small rodents (reservoir hosts)
Infected nymph
Infected adult
Large animals (maintenance hosts)
Susceptible animals human, dog, horse

10. Susceptible animals human, dog, horse
blood stream through out the body(multiply)
localized at skin(rash) joints, brain, nerves, eyes, heart
Lyme disease

12. Human : B. burgdorferi Lyme Disease (continue)
* endemic area : -American south & farwest, Europe
* deer, mice and other rodents serve as reservoir
* B. burgdorferi isolated from urine of dog & cows as well as milk from infected cow (infrequent)
Human : B. burgdorferi
* skin lesion (erythema migrans) for wks and months
* later by neural, cardiac, arthritic complication

14. Dog : (frequently) Horse & Cattle : * polyarthritis, fever, anorexia
* lymphadenopathy, carditis
* renal disease
Horse & Cattle :
* abortion in cattle
* polyarthritis, ocular and neural involvement in horses
* foal mortality

15. Lyme arthritis
Tick paralysis

16. IMMUNITY
humural immune appears essential for protection against B. burgdorferi infection
most animals appear to self-immunize with no apparent clinical manifestation subsequent to exposure to the spirochetes

17. Relapsing fever ornithodorus spp.
B. hermsii tick-borne (animal to human) ornithodorus spp. Feed for short periods of time borrelia are inoculate within minutes more relapse, more fatality B. recurrentis louse-borne (human to human) long febrile & afebrile interval longer incubation period

19. Relapse phenomenon
Outer surface proteins of borrelia allows a new clone to avoid antibodies directed against the original infecting organism the patient clinically improves until the new clone multiplies sufficient to cause another relapse

20. PATHOGENESIS Enter the host Generalized infection after one week
spirochaetemia
Fever, headahe, muscle pain (4-10 days)
Afebrile period (5-6 days)
Absence of spirochaetemia
1 relapse (louse-borne),3 relapse (tick-borne)

21. Immunoavoidance mechanism of borrelia illustrating the
antigenic variants infection

22. Animal Borrelioses : Borrelia anserina (Argas spp.)
* fowl spirochetosis in chickens, turkeys, geese, ducks, pheasants, pigeons, canaries, some wild bird
* fever depression anorexia
* greenish diarrhea
* paralysis and anemia
* splenomegaly, widespread hemorrhage
* enlarged liver contains necrotic foci

23. Borrelia theileri (cattle, sheep, horse)
* mild febrile anemia

24. ISOLATION AND IDENTIFICATION
1. Demonstration of the agent in tissues and fluids (dark field, immunofluorescence microscopy)
2. ELISA (antibody detection)
3. PCR (tissue or fluid)
4. Culture is laborious from synovial fluid
5. Antibody in serum or other fluid (indirect IF test)

26. B. burgdorferi (dark field)

27. Pathogens : Species Hosts Specific Diseases
B. anserina birds Avian borreliosis
B. burgdorferi canine Canine borreliosis
man Lyme disease
B. theileri bovine bovine borreliosis
equine equine borreliosis
other species man tick-borne relapsing
fever

28. Brachyspira/ Serpulina
Leptospira
Borrelia
Brachyspira/ Serpulina
found in aquatic environment
systemic infection
shed in urine
liquid media 30 0C aerobic
dark field, silver stain, IF
transmitted by arthropod vector
systemic infection
culture from affected animal
special media C microaerophilic
dark field, IF
Intestinal spirochaetes (pig)
localize
culture from affected intestine
special blood media 42 0C anaerobic
silver stain, faeces histopatho section, IF