Effects of pH on the Pathogenicity ofandon the Kidney: In Vitro and In Vivo Studies.

Abstract

Urine pH reflects the functional integrity of the body and may influence the virulence of uropathogenicand, the main causes of urinary tract infections (UTIs). This study evaluated the effects of acidic pH on the pathogenicity of uropathogenicandstrains, in vitro and in vivo. Four uropathogenicand fourstrains were used. Biofilm formation, growth competition indices, motility, and adhesion and invasion of human renal cells were analyzed in media with acidic, neutral, and alkaline pH. A murine lower UTI model was used, with urine adjusted to acidic, neutral, or alkaline pH. At acidic pH,andexhibited higher bacterial concentrations in the kidneys and systemic symptoms, including bacteremia. Alkaline urine pH did not affect bacterial concentrations of any strain. In mice with UTIs caused byNu14 andHUVR42 and acidic urine pH, histopathological studies of the kidneys showed acute inflammation affecting the urothelium and renal parenchyma, which are traits of acute pyelonephritis. These results indicate that acidic pH could increase the pathogenicity ofandin murine models of lower UTI, promoting renal infection and acute inflammation.