Organism Classification
- Leptospira are spiral-shaped bacteria (spirochetes) that belong to the family Leptospiraceae 2, 3
- The genus Leptospira includes at least 12 pathogenic and 4 saprophytic (free-living) bacterial species 4
- These are morphologically and phylogenetically unique bacteria, not viruses 3
Key Distinguishing Features
- Leptospira are helical bacteria with a characteristic spiral shape that distinguishes them from viruses 4
- They can be cultured and isolated from clinical specimens (blood, urine, cerebrospinal fluid), which is a bacterial characteristic—viruses require cell culture systems 5
- Laboratory diagnosis includes bacterial isolation techniques and agglutination testing specific to bacterial antigens 5, 6
Clinical Relevance
- Leptospirosis is caused by infection with bacteria of the Leptospira species, transmitted through contact with urine from infected animals or contaminated water 1, 7
- The disease is treated with antibiotics (penicillin or doxycycline), which target bacteria, not viruses 6, 8
- Diagnostic methods include bacterial culture, serological testing for bacterial antibodies, and PCR for bacterial DNA 8, 7
Common Pitfall
Do not confuse the spiral morphology of Leptospira with viral particles—spirochetes are a distinct class of bacteria with a helical structure, cell wall, and metabolic machinery that viruses lack 2, 4