Related Experiment Videos
The effect of uropathogenic bacteria on ureteral motility
1Department of Pharmacology-Toxicology, Faculty of Medicine, Kuwait University, Safat.
Abstract:
The effect of bacterial products of various strains obtained from patients with urinary tract infections was tested on peristalsis of sheep ureteral rings. In 55-70% spontaneous rhythmic contractions were inhibited by addition of small amounts of growth supernatants from Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae. The isolates were also tested on mesenteric artery ring preparations. In these vessels the isolates induced tonic contractions, particularly when the vessel had been depolarised and precontracted with a 40 mM KCl solution. This response is characteristic of a calcium ionophore, known to occur in some bacterial toxins. The active principle of the bacterial ureteroplegic factor (BUF) is heat sensitive and distinct from endotoxins which speed up peristalsis. It is suggested that the ureteroplegic action depends on an exotoxin with ionophoric properties.
Insights
Bacterial products from urinary tract infections inhibited sheep ureter contractions. These potent bacterial ureteroplegic factors (BUF) may act as exotoxins with calcium ionophore properties.
Area of Science:
- Microbiology
- Pharmacology
- Urology
Background:
- Urinary tract infections (UTIs) are common and can lead to complications.
- Bacterial products are implicated in the pathophysiology of UTIs.
- The specific mechanisms by which bacteria affect ureteral function are not fully understood.
Purpose of the Study:
- To investigate the effects of bacterial products from UTI pathogens on ureteral smooth muscle.
- To characterize the nature of the active bacterial component responsible for ureteral effects.
Main Methods:
- Sheep ureteral rings and mesenteric artery rings were used as ex vivo preparations.
- Bacterial growth supernatants from Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae were applied.
- Effects on spontaneous contractions and induced tonic contractions were measured.
Main Results:
- Bacterial supernatants inhibited spontaneous ureteral ring contractions in 55-70% of cases.
- Bacterial isolates induced tonic contractions in mesenteric artery rings, especially after depolarization.
- The active factor (bacterial ureteroplegic factor, BUF) was heat-sensitive and distinct from endotoxins.
Conclusions:
- Bacterial products from UTI pathogens can significantly impair ureteral peristalsis.
- The ureteroplegic effect is likely mediated by a heat-sensitive exotoxin with calcium ionophore properties.
- This finding suggests a novel mechanism for bacterial-induced urinary tract dysfunction.