Virulence factors of Escherichia coli contribute to acute renal failure.
BACKGROUND
The development of acute renal failure (ARF) significantly enhances the mortality of patients with Gram-negative septic shock. The role of specific bacterial virulence factors different from lipopolysaccharides (LPS) in the deterioration of renal function in septic shock remains to be determined.


METHODS
An Escherichia coli wild-type strain (536/21 WT, O6:K15:H31) was isolated from a patient suffering from a urinary tract infection. The strain expresses various virulence factors (e.g. hemolysin, fimbriae) genetically encoded by pathogenicity islands. The spontaneous deletion mutant 536/21 Del lacks the expression of these virulence factors. Isolated rat kidneys were perfused with a suspension (5 x 10(4)/ml) of the respective strain or control perfusion medium and the renal functional parameters were analyzed. Intrarenal deposition of E. coli was detected by immunohistology and Gram staining.


RESULTS
The perfusion of the isolated perfused rat kidney with a uropathogenic E. coli wild-type strain (536/21 WT) caused an acute deterioration of renal function which was not observed in kidneys exposed to a deletion mutant of E. coli 536/21 lacking the expression of virulence factors. The glomerular filtration rate and the urine flow rate significantly decreased only in kidneys perfused with the E. coli wild-type strain, while there was no change versus controls in kidneys perfused with the deletion mutant.


CONCLUSIONS
Distinctive bacterial virulence factors different from LPS such as hemolysin and the presence of different fimbriae may contribute to the development of ARF in sepsis induced by E. coli. Anti-LPS strategies may not be sufficient to reduce the risk of ARF in Gram-negative septic shock.
Kreft
B
B
Department of Nephrology, Medical University, Lübeck, Germany.
Pagel
H
H
D058186:Acute Kidney Injury / Q000382:microbiology* / Q000503:physiopathology; D000818:Animals; D001422:Bacterial Adhesion; D001783:Blood Flow Velocity; D004730:Endothelium, Vascular / Q000382:microbiology; D004926:Escherichia coli / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity*; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000098:blood supply / Q000737:chemistry / Q000382:microbiology; D008070:Lipopolysaccharides / Q000032:analysis; D008297:Male; D009154:Mutation; D051381:Rats; D017207:Rats, Sprague-Dawley; D014552:Urinary Tract Infections / Q000382:microbiology; D014655:Vascular Resistance; D014774:Virulence
D008070:Lipopolysaccharides