Leptospira spp.

MICROBIOLOGY

• Leptospira is one of the spirochetes [Fig 1] pathogenic for humans (other examples are Borrelia burgdorferi, which causes Lyme disease, relapsing fever Borreliae, and Treponemes, e.g., Treponema pallidum [syphilis]).
  • Organisms don’t replicate in the environment but may survive in standing water or contaminated soils.
• Leptospira is a member of Leptospiraceae and is divided into 20 species based on DNA hybridization. Previously, multiple species were described (66) and may also be classified by serovars (>300). Leptospira spp are pathogenic and non-pathogenic for humans. Further divisions into subclades for human pathogens
  • Species may cause severe illness: L. alexanderi, L. alstonii, L. borgpetersenii, L. interrogans, L. kirschneri,L. kmetyi, L. mayottensis, L. noguchii, L. santarosai, and L. weillii.
  • Others may cause mild illness or in the setting of immunocompromise.
• Leptospirosis is a zoonotic disease transmitted by wild and domestic animals (dogs, cattle, pigs, and more) and rodents (rats and mice).
  • Infected urine from animals -->waters, soils.
• Challenging to culture in the laboratory, fastidious.
  • Liquid media is preferred (e.g., modified Ellinghausen McCulloughJohnson Harris (EMJH) medium +/- 5-FU), temperature 29-32°C. Doubling time 6-18h.
  • Aerobic, but CO₂ is needed; aeration appears to help growth.