Unit 4- Spirochetes Flashcards
Important Genera
Treponema, Borrelia, Brachyspira, and Leptospira
Spirochetes
Spiral, motile, gram neg, transverse fission division, outer sheath, axial filament
Axial Filament
Inserts through proximal hook and runs along protoplasmic cylinder under the outer sheath to act as a flagella and provide motility along a helical path
Staining
Too thin to ID by gram stain, use darkfield, phase contrast, immunofluoresence, or silver
Borrelia
Microaerophilic, slow growing, motile, gram stain, silver stains, giemsa, or darkfield, require LCFA glucose and amino acids for growth, tick intermediate host
Lyme Disease
Borrelia burgdorferi, aerobic and fastidious, low numbers in infected animals, difficult to culture, ixodes tick vectors, reservoir hosts to small rodents
Lyme Pathogenesis
B burgdorferi LPS and peptidoglycan elicit inflammation, peptidoglycan causes arthritis, IL-1 release causes fever, rash, arthropathy, and antibody synthesis
Lyme Persistence
Infection can progress and bacteria remains, autoimmune reaction can contribute
B. burgdorferi Virulence Factors
Phase variation of surface antigens, motility, and resistance to host immunity
Horse Lyme
Uncommon, cranky attitude, sore back, lameness, fever, depression, arthritis, uveitis, encephalitis, fetal death
Dog Lyme
Asymptomatic or symptomatic, fever, lymphadenopathy, inappetence, lethargy, lameness in front legs, CNS infection, renal disease
Cattle Lyme
Rare, lameness, fever, loss of appetite, fetal death
Human Lyme
Days to weeks before rash occurs, systemic infection, fever, fatigue, rash, arthritis, lymphadenopathy, CNS and PNS, chronic arthritis, neurologic symptoms, heart infection
B. burgdorferi Immunity
Humoral immunity, spirochetes killed by antibody and complement, bacterial DNA and autoimmune reaction lead to chronic infection
B. burgdorferi Diagnosis
History, clinical signs, staining, serology, western blot, dogs can be asymptomatic carriers
