All authors read and approved the final manuscript.”
“Background Leptospirosis, the most common zoonotic illness affecting humans, is caused by spirochetes of XAV-939 order the genus Leptospira[1, 2]. Some Leptospira species live exclusively in water or soil, while others cycle between environmental and mammalian reservoirs. Leptospira can colonize/infect

renal tubules of a wide variety of wild and domesticated mammals. Human disease follows exposure to water or soil contaminated with urine of infected animals. Leptospirosis can be asymptomatic, or manifest as a mild flu-like illness. In another subset of individuals (5-10 % of patients) Leptospira can produce more serious systemic infections resulting in pulmonary hemorrhage, jaundice, renal failure, refractory shock, myocarditis, and/or aseptic meningitis. Despite its medical importance, few virulence determinants of pathogenic Leptospira have been characterized in any detail.

Investigation of the organism is hampered by its fastidiousness, slow growth in culture and the lack of available genetic tools. To date, only Omp-A like lipoprotein Loa22 has been demonstrated Repotrectinib ic50 to be necessary for virulence, appearing to be cytotoxic and capable of inducing apoptosis. [3–5] LipL32, a major outer membrane protein of pathogenic Leptospira, is expressed in vivo and, although it has been shown to bind to host extra-cellular membrane, LipL32 does not seem to be required for acute or chronic infection in vivo in animal models. [6, 7] Other potential virulence leptospiral factors include LigA and LigB that contain immunoglobulin-like repeats associated with adhesion to host cells in other gram-negative bacteria. Other proteins shown to have laminin binding activity in-vitro include LenA/LfhA/Lsf24 and related proteins LenBCDEF. LenA seems to also bind factor H of complement, so it might have more than one role in virulence. [8, 9]. Leptospiral LPS, although not characterized in detail, has some unique characteristics tuclazepam which could explain why

it is poorly recognized by the TLR4- MD2 complex. This diminished recognition could contribute to leptospiral survival in the bloodstream and dissemination. Other potential virulence factors for which more evidence remains to be published include mediators of motility and chemotaxis, including chemotaxis towards hemoglobin [10]. Sialic acids are a diverse family of acidic nine-carbon backbone (nonulosonic) monosaccharides found in abundance on the surfaces of mammalian cells and are sometimes expressed by microbial pathogens. The most common sialic acid in nature is N-acetylneuraminic acid (Neu5Ac). Expression of Neu5Ac by pathogenic bacteria has been linked mechanistically to complement and neutrophil evasion in disseminated infections with Streptococcus and Neisseria and with the induction of autoimmune neuropathy following infection with Campylobacter.