Growth of Escherichia coli in Human Urine: Role of Salt Tolerance and Accumulation of Glycine Betaine

Publisher Website
Google Scholar
Abstract
Glycine betaine is a powerful osmoprotectant molecule present in the inner medulla of the kidneyand excreted into urine. It may be responsible for the ability of Escherichia coli to grow in hypertonic urine. Also, strains of E. coli that cause urinary tract infections may be more salttolerant than strains from other sites. To explore these questions, 301 isolates from blood, urine, or stool and 12 representative enteric strains wereexamined. Tolerance varied from 0.1 to 0.7 M NaCI (median, 0.5) in minimal medium. There wereno significant differences in salt tolerance by site of isolation. A salt-sensitive enteric strain that responded poorly to glycine betaine and mutant strains lacking the ability to synthesize or transport glycinebetaine did not grow well in hypertonic urine. Accumulation of glycine betaine appears to be a mechanism by which E. coli can adapt to external osmotic forces and grow in hypertonic urine.

This publication has 0 references indexed in Scilit: