Leptospira interrogans is a species of obligate aerobic spirochaete bacteria shaped like a corkscrew with hooked and spiral ends.
[2] Human infections are commonly spread by contact with contaminated water or soil, often through the urine of both wild and domestic animals.
[7][8] L. interrogans has many properties that ensure its optimal survival in specific conditions, including two periplasmic flagella for movement and mobility.
[9] The species uses beta oxidation of long chain fatty acids for energy, in which oxygen and peroxides are used as the main terminal electron acceptors.
[14][12] The optimal growth of the obligate aerobe L. interrogans occurs in simple media containing vitamins, salts, and specific long chain fatty acids.
Through naturally occurring phase interfaces or its growth media, L. interrogans must physically obtain the long chain fatty acids in order to further metabolize them as an energy source.
[15][17] Evidence has also shown that peroxides such as H2O2 can also serve as a terminal electron acceptor, with catalase activity needed for survival in vivo.
[11] Genes specifically encoding for long-chain fatty-acid usage, the TCA cycle, and electron transport chain have also been identified in L. interrogans.
Although LipL32 binds to a number of extracellular matrix components in test tube experiments, there is doubt regarding where this protein is located.
[23][24] Some outer membrane proteins, such as OmpL1, aid in the infection process of L. interrogans by allowing adherence to host cells's surface molecules.
[19] The bacterial chaperone ClpB is a major driver in the overall virulence of L. interrogans, as it aids in survival inside the host, the control of stress responses, and the unique role of protein disaggregation.
[17] Rats are the primary carrier of leptospirosis but do not present any symptoms, transmitting the pathogen through urine, which is able to persist in freshwater.
[17] Leptospira often enter the body through open cuts and other wounds, though they are unable to pass through an intact skin barrier.
[29] It has been shown in studies that L. interrogans may damage the endothelial cell lining of various vessels and organs, allowing them to leak and further spread the bacteria to other parts of the body.
Phase 1 of infection is anicteric, and symptoms include fever, chills, headache, muscle aches, vomiting and diarrhea.
This inflammatory response results in the high expression of tumor necrosis factor alpha, referred to as TNF-α, in the uterine tissue of infected dogs.