Klebsiella spp., particularly Klebsiella pneumoniae, are important causes of nosocomial infections. K. pneumoniae infections may occur at almost all body sites, but the highest incidence is found in the urinary and respiratory tracts. Lipopolysaccharides (LPS), also known as lipoglycans and endotoxins, are large molecules consisting of a lipid and a polysaccharide composed of O-antigen, outer core and inner core joined by a covalent bond; they are found in the outer membrane of Gram-negative bacteria.