Staphylococcus saprophyticus is a coagulase-negative species of Staphylococcus. Like other Staphylococci, it is Gram-positive, is globular shaped, and is a facultative anaerobe. It has abundant transporter systems to adapt to ever changing pH, osmolarity, and concentration of urea in human urine. [1] One of the adaptations is the gene expressed in the two plasmids. The plasmids contain a gene coding for aquaporin Z. The amount of water channels created is regulated by the number of copies of the plasmids. [1] To regulate pH, S. saprophyticus contains two Na+/H+ antiporters which keep the cell at homeostasis by the uptake of protons. [1] Bacteria need iron for survival. S. saprophyticus lacks siderophores, but uses other means to acquire iron. It has both a pH-driven symporter and a sodium-dependent symporter to transport divalent cations, including iron, into the cell. [1] These transport systems allow for S. saprophyticus to grow rapidly in the urinary tract.
S. saprophyticus contains urease, which hydrolyzes urea and produces a derivative of ammonia. This is how the cell metabolizes Nitrogen. Urease activity is known to be an infection causing factor in UTIs. [1]
S. saprophyticus contains an autolysin that is thought to be involved in binding fibronectin. [6] It has also been found that S. saprophyticus contains a 160-kDa surface polypeptide that acts as the hemagglutinin and mediates the binding of fibronectin. The antibody to the poplypeptide inhibits hemagglutination. [7] S. saprophyticus contains a specific adhesin contributing to the adhesion to eukaryotic cells in the urinary tract