Leptospira Medium Base, 500 g

Leptospirosis is an acute febrile disease caused by members of the genus Leptospira (1,2). Direct culture of blood is the most reliable way to detect Leptospira during the first week of illness. After the first week of illness and for several months thereafter, leptospires may be isolated by direct culture of undiluted urine specimens. By autopsy, leptospires may be isolated from kidney and liver tissues as well as from blood and urine. The Leptospira Medium Base was originally formulated by Ellinghousen and McCullough (3) and modified by Johnson and Harris (4). Leptospira Medium Base is enriched by the addition of Leptospira Enrichment. Leptospira Enrichment supplement provides long chain fatty acids as the carbon, energy source and vitamin for the growth of Leptospira . The salts supply essential nutrients for the growth of the organisms. Phosphates form buffering system while sodium chloride maintains osmotic equilibrium and also provides essential ions. Leptospira metabolizes the fatty acids by beta-oxidation and the metabolic end products formed are acetate and carbon dioxide. All cultures are incubated at room temperature in the dark for up to 6 weeks. The organisms grow below the surface. Material collected from a few centimeters below the surface of broth cultures should be examined weekly for the presence of growth using a direct wet preparation under dark field illumination. Letpospires will exhibit corkscrew like motility (1). Examine the tubes for growth every 5-7 days. Growth occurs as a ringed area (disc) 1-3 cm below the surface of the medium. The absence of a ringed area of growth doesnt necessarily mean leptospires are not present. Remove a small amount of growth from the disc area and examine microscopically (gram stain is not satisfactory). Microcolonies can be fixed with methanol and stained with Giemsas stain to show rod forms (5). Storage and Shelf-life: Store below 30°C in tightly closed container and prepared medium at 2-8°C. Use before expiry period on the label. References: 1.Forbes B. A., Sahm A. S., and Weissfeld D. F., Bailey & Scotts Diagnostic Microbiology, 10th Ed., 1998, Mosby, Inc., St. Louis, Mo. 2.Murray P. R., Baron J. H., Pfaller M. A., Jorgensen J. H. and Yolken R. H., (Ed.), 2003, Manual of Clinical Microbiology, 8th Ed., American Society for Microbiology, Washington, D.C. 3.Ellinghausen and McCullough, 1965, Am. J. Vet. Res., 26:39. 4.Johnson and Harris, 1967, J. Bact., 94:27. 5.Korthof G., 1932, Zentralbl. Bakteriol. Parasitenkd. Infektionskr. Hyg. Abt. I. Orig., 125:429.