Module 2 (Spirochetes) Flashcards
These are a diverse group of pathogens that infect humans and animals.
Spirochetes
What are the 3 genera of Spirochetes?
- Borrelia
- Treponema
- Leptospira
• Arthropod-borne pathogens
• Transmitted by ticks
• Possess a blood-borne phase
Borrelia
Species of Borrelia associated with animal infections.
- B. anserina (fowl spirochaetosis)
- B. theileri (Cattle relapsing fever)
- B. burgdorferi (lyme disease of dogs, horse, and cattle)
- B. coriaceae (Epizootic bovine abortion)
- B. canis (Intestinal diseases of dogs)
- B. hyos (Swine pathogen)
Gram negative but stain well with Giemsa and Wright
Borrelia
Spirals with characteristic motility (darkfield microscopy)
Borrelia
Possess axial fibrils which differ across species
Borrelia
Pathogens possess a linear double-stranded chromosome
Borrelia
Grows well in embryonated eggs
Pathogenic Borrelia
B. burgdorferi can be cultivated in Modified Kelly’s medium at what degrees Celsius?
33°C
They ferment glucose and other carbohydrates; can be either anaerobes or facultative anaerobes
Borrelia
Borrelia reservoir of infection
- Wounds
- Placenta
- Milk
- Urine
- Feces
Transmission of Borrelia
- Through tick vectors
- Trans-ovarian (maternal)
- Cannibalism
- B. anserina
- Carried by Argas persicus (avians)
- Signs: cynosis and greenish diarrhea, paralysis, and anemia
- Findings: Splenomegaly and liver enlargement
- Fowl spirochaetosis and Goose Septicemia
- B. burgdorferi
- Ixodes scapularis, Ixodes pacificus
- dogs, horses, cattle, humans
- sign: skin lesions, arthritis, neural involvement, lymphadenopathy, and abortion
Lyme Disease
What are the virulence factors of Pathogenic Borrelia?
- Muramic acid and ornithine cell wall
- Endotoxins
- Hemolysin
Laboratory diagnosis of Borrelia
Samples:
- liver
- blood
- synovial fluid
- spleen
Preferred culture media:
- chick embryo
Agent Identification of Borrelia
- Demostration in Giemsa-stained blood
- Inoculation at 33°C
- Dark microscopy
- ELISA
- PCR using genus specific DNA primers
Treatment of Borrelia with antibiotics
- Penicillin
- Streptomycin
- Tetracycline
- Doxycycline
- Enrofloxacin
- Erythromycin
Control and prevention of Borrelia
-Tick control
-Ectoparasite control