A practical review of leptospirosis (Proceedings)
•Most common zoonosis worldwide.
•Bacterial disease caused by pathogenic Leptospira species affecting domestic animals, wildlife, and humans.Leptospira
•smallest spirochete bacteria
(0.1 µm x 6-30 µm)
•pointed ends which are bent into distinctive hooks
•Does not stain well!
•spirochetes - typical double membrane structure
•Cytoplasmic membrane and peptidoglycan cell wall are closely associated and overlain by an outer membrane
•composition similar to other gram-negative bacteria, but lower endotoxic activity
•Surface protein/outer membrane proteins (OMPs)
•Lipopolysaccharides (LPS) and lipoproteins
•LPS – highly immunogenic, responsible for
Cornell and Gluck are looking at these surface proteins to help improve serologic testing
•Leptospira in rivers, lakes, and sewage.
•Heat (>93 F) and Cold (< 50 F)
•Detrimental to the organism
•> 8 or < 6 pH not suitable for survival
•Soil contaminated with urine
•~ 2 weeks (RATS or VOLES)
•~ 7 weeks (New Zealand Winter)
•Increased prevalence during rainy periods in spring and fall.
• September 23 – November 3 Average temp was >65 compared to ↓ 65 baseline year(Dr. Hall Thesis 2005)
•Host-adapted - most common reservoirs are raccoon, skunk, deer, cattle, swine, and rats.
•Equine - adapted host – Bratislava
• Never isolated from the horse but high titers (Persistent)
•Exposure occurs when horses consume contaminated groundwater that contains urine shed from a host-adapted species.
•Leptospira are able to penetrate mucous membranes and abraded skin.
•Rapidly gain access to vascular space.
•Bacteremia persists for about 8 days.
•FEVERS 103-106 F 7-9 days after exposure (US Livestock Sanitary Assoc- Morter et al, 1964, JAVMA 1969)
•Invasion of many internal organs occurs.
•The infection induces a strong host antibody response – 1st detectable in serum 4-8 days after exposure. (US Livestock Sanitary Assoc- Morter et al, 1964, JAVMA 1969)
•Maintain for up to 7 years (Swart Aus Vet J 1982)
•Organisms are eliminated rapidly from the blood and most organs by host mechanisms – TH2-response.
•Localization of organisms may occur in :
• Renal tubules