Leptospira interrogans
Brittany Bockorst

Leptospira interrogans is a zoonotic, aerobic, gram-negative, flat, spiral-shaped spirochete that was first examined in the tissue of a kidney in 1907. It is unique among other spirochetes in the fact that its outer membrane not only contains lipopolysaccharides, but also lipoproteins as well. These proteins on the cell surface are used to attach to the extra cellular matrix of the host. It consists of only two chromosomes and has two flagella as a source of motility. The genus Leptospira has twenty species that are separated based on DNA hybridization studies.

Leptospira interrogans lives in a diverse group of habitats all over the world. It has been observed in every continent except Antarctica. It prospers in conditions of high humidity, neutral pH around 7.2, temperatures as low as 13-15 degrees Celsius, and in wet areas such as swamps, bogs, lakes, streams, rivers, and even puddles. When reproducing they multiply via binary fission. They bend and then split into two at the crease. This organism utilizes long-chain fatty acids, synthesized through beta-oxidation, as it’s only source of energy. Iron is a very important element needed for the growth of this microbe. While inside a host, it uses heme from the blood of its host, as its source. They are typically six to nine micrometers in length and grow from one end.

Leptospirosis is the disease caused by Leptospira interrogans. It is a disease that results in symptoms such as severe muscle pain, fever, jaundice, headache, meningitis, ocular disorders, renal failure, and even pulmonary hemorrhage. This microbe is often transmitted indirectly through water and soil that is contaminated with the urine of infected animals. It is then transferred from the infected animal to humans via breaks on the skin surface, mucous membranes, or oral ingestion. There have been cases of people acquiring the disease directly through the water source in which the Leptospira interrogans in thriving, however, it is more commonly passed to humans through their infected pets. During a triathlon in 1998 in Springfield, Illinois many participants came down with Leptospirosis, later to find out that the lake in which they swam for the event was contaminated with Leptospira interrogans. During the winter months many of these organisms die, but the ones that survive are picked up by animals like raccoons and deer, where they multiply significantly before being excreted. This organism once inside its host, flows through the blood stream and settles in the kidneys. Antibiotics can usually be effective in the treatment of Leptospirosis if it is caught early enough. If it’s too late, it can be fatal due to organ failure.







*Disclaimer - This report was written by a student participaring in a microbiology course at the Missouri University of Science and Technology. The accuracy of the contents of this report is not guaranteed and it is recommended that you seek additional sources of information to verify the contents.


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