The in vitro effects of Salmonella enteriditis on urinary stone formation

Salmonella enteriditis has been previously found to have both unique inhibiting and augmenting properties on urinary stone formation. A series of in vitro experiments were performed in order to determine if the in vivo results could be explained in an in vitro model. Urinary phosphorus was measured before and after incubation with various bacteria, and was found to increase significantly when incubated with S. enteriditis (p less than 0.05). Urinary citrate was measured in a similar fashion following incubation with S. enteriditis and E. coli. A statistically significant decrease in urinary citrate was found in urine incubated with S. enteriditis (p less than 0.005). Based on the results of these experiments the increase in urinary phosphorus may have contributed to the inhibiting foreign body stone formation in a previous in vivo model. The decrease in urinary citrate could explain the augmentation of calcium phosphate stone formation previously reported.