Inhibiting effect of synthetic urine on the growth and mobility of Pseudomonas aeruginosa, Escherichia coli, Proteus mirabilis and Klebsiella pneumoniae shifts to a promoting effect during culture

Abstract

　Incontinence-associated dermatitis (IAD) is caused from the repeated exposure to urine/faeces and reduces quality of life. However, the underlying mechanisms are poorly understood. This study explored the effects of urine on the growth and motility of common uropathogens. Pseudomonas aeruginosa, Proteus mirabilis, Escherichia coli and Klebsiella pneumoniae were grown for 24 hrs at 37℃ in Luria-Bertani (LB) medium supplemented with various concentrations of synthetic urine. Bacterial growth was monitored over time by measuring absorbance at 600nm. Swimming, swarming, and twitching motilities were determined in cultures of LB with (1: 1 ratio) and without synthetic urine. Results demonstrated that bacterial growth was inhibited during early phase (0-6 hrs), and enhanced after 8 hrs. For P. mirabilis and K. pneumoniae, the increase in growth was in a dose-dependent manner. Swimming motility of P. mirabilis was inhibited. This study suggested the different effect of fresh and infectious urine on the bacterial growth, which is important to understand the mechanisms of IAD development due to urine incontinence.