Unit 4- Leptospira Flashcards
Leptospira
Gram negative, spirochete, hooks, axial filament between outer envelope and cytoplasm, aerobe, LCFA carbon course, fastidious, sensitive to heat, light, and disinfectants
Non Pathogenic Leptospira
L. biflexa
Pathogenic Leptospira
L. interrogans
Pathogenic Species
L. alexanderi, alstonii, borgpetersenii, inadai, interrogans, fainei, kirschneri, licerasiae, noguchi, santarosai, weilii, kmetyi, broomii, and wolfii
Location
Lumen of nephritis tubules, survives mud and water after excretion in urine, host preference, cannot survive in salt, low pH, cold, or low humidity
Horse Leptospira
L. kennewicki, bratislava, and pomona
Pig Leptospira
L. pomona, canicola, and icterohemorrhagiae
Cattle Leptospira
L. pomona, icterohemorrhagiae, and hardjo
Wildlife Leptospira
L. pomona and grippotyphosa
Dog Leptospira
L. canicola, icterohaemorrhagiae, and grippotyphosa
Leptospira Virulence
LPS, catalase, motility, sphingomyelinase, cytotoxins, cellular invasion
Disease
Premature birth, abortion, infertility, jaundice, agalactia, hemoglobinuria, dogs develop hemorrhagic or icteric and uremic syndrome, cats rarely show signs
General Clinical Signs
Fever, inappetence, malaise
Cattle Acute Clinical Signs
L. pomona, abnormal milk, rash, muscle pain, GI signs, photophobia, encephalitis, nephritis, hemoglobinuria, increased BUN
Cattle and Swine Chronic Clinical Signs
L. pomona, abortion, stillbirth, nephritis, uveitis, encephalitis, and infertility due to antigen-antibody complexes
Weak Calves Cause
L. hardjo chronic infection
Dog Forms
Hemorrhagic, icteric, and uremic forms, kidney failure, liver disease, and shock
Pathogenesis
Entry through wound or mucous membrane, low infectious dose, outer sheath anti-phagocitic for blood persistence, replication in liver, enters tissues
Hematogenous Spread
Hepatic and renal disease, mainly spreads to kidneys, vascular damage and endothelial disruption, bile duct occlusion, jaundice, nephritis
Carrier State
Antibodies clear bacteria from blood and organs but they remain in nephric tubules with no clinical signs, happens in rats
Persistent Infection
Infect fetuses of large animals
Transmission
Asymptomatic carriers, exposure to contaminated urine, transplacental, milk, venereal
Immunity
LPS antigen, antibodies clear from blood by opsonization, serovar-specific antibodies, not protective against other serovars
Control
Bacterin vaccines for local serovars, prevent exposure
Diagnosis
Darkfield microscopy, serology, microscopic agglutination, ELISA, isolation, Dinger’s ring, silver stain
Best Test
Microscopic Agglutination Test MAT
Dinger’s Ring
Aerobic bacteria appear as a diffuse zone and then ring near the top of the tube
Ellinghausen-McCullough-Johnson-Harris Medium
Salts, thiamine, pyruvate, glycerol, albumin, Tween 80, B12
Treatment
Antibiotics, may not eliminate from kidney and leads to carrier state
Jarisch-Herxheimer Reaction
Endotoxic shock when leptospira is treated with penicillin, add steroids to treatment
Zoonosis
Children swimming in contaminated water at risk, Weil’s disease, flu-like illness
Weil’s Disease
Fever, jaundice, hemorrhage, pulmonary distress, splenomegaly, nephritis, and death
