Fontana Stain For Leptospira: High Efforts Or High Rewards

Early detection of leptospirosis is crucial since early antibiotic treatment improves diagnosis.   Tests like MAT (Microscopic Agglutination Test), PCR (Polymerase Chain reaction) and culture are used in laboratory diagnostics. However, these diagnostic options are costly and time-consuming, and they are only available in specialised diagnostic laboratories. 

Leptospira can be directly demonstrated in clinical specimens using microscopy, which can offer an early and quick diagnostic opportunity. They are spiral and thin bacteria which cannot be stained by the Gram stain. However, leptospira can be stained using the modified Fontana method, relatively inexpensive, that allows stained organisms to be seen with a standard light microscope, which is readily available in a basic laboratory setting. 

By deposition of silver on the surface of leptopires, the Fontana method increases their thickness and makes them visible under light microscopy. The method entails applying a mordant on the specimens, followed by a solution of silver nitrate, which is then oxidised to metallic silver on the bacterial surface.

So, a quick and easy test for detection of leptospira especially in urine is the modified Fontana staining procedure. It should be taken into consideration that modified Fontana stain may provide supporting evidence for diagnosis in regions with high prevalence in the absence of other quick diagnostic testing.

In conclusion, this stain is one of them that demonstrates the philosophy that putting in a lot of work and applying it honestly will yield amazing results.