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[Experimental bladder stone production by human uropathogenic bacteria]
Y Arai1, H Takeuchi, T Tomoyoshi
1Department of Urology, Shiga University of Medical Science.
Abstract:
To investigate the formation of infection stones by 5 bacterial species isolated from patients with urinary calculi, such as Proteus mirabilis, Staphylococcus saprophyticus, Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli, a zinc disc was implanted and 10(6) bacteria were surgically inoculated at the same time into the bladder of male Wistar rats (10 rats per group). Urinary pH was measured on days 1, 3, 5 and 7. The rats were killed on day 7 and the bladder examined for the formation of infection stones. Infection stones were formed in all rats inoculated with P. mirabilis (mean stone weight 29.7 mg), and in 60% of those inoculated with S. saprophyticus (9.7 mg). Small bladder stones were formed in 30% of the rats inoculated with K. pneumoniae and 25% of those inoculated with P. aeruginosa. No bladder stones were formed in the rats inoculated with E. coli. Urinary pH was increased by P. mirabilis and S. saprophyticus but was unaffected by the other species. In conclusion, P. mirabilis and S. saprophyticus play a significant role in the formation of infection stones.
Insights
Proteus mirabilis and Staphylococcus saprophyticus significantly contribute to infection stone formation in the urinary tract. These bacteria increase urinary pH, promoting the development of bladder stones in rat models.
Area of Science:
- Urology
- Microbiology
- Biomedical Science
Background:
- Urinary calculi, or infection stones, are often associated with specific bacterial species.
- Understanding the role of different bacteria in stone formation is crucial for developing effective treatments.
Purpose of the Study:
- To investigate the capacity of five common urinary tract bacterial species to form infection stones.
- To determine the impact of these bacteria on urinary pH in a rat model.
Main Methods:
- Male Wistar rats were inoculated with Proteus mirabilis, Staphylococcus saprophyticus, Pseudomonas aeruginosa, Klebsiella pneumoniae, or Escherichia coli.
- Zinc discs were implanted, and bacterial inoculation occurred in the bladder.
- Urinary pH was monitored, and bladders were examined for stone formation on day 7.
Main Results:
- Proteus mirabilis and Staphylococcus saprophyticus induced significant infection stone formation.
- Klebsiella pneumoniae and Pseudomonas aeruginosa caused small bladder stones in some rats.
- Escherichia coli did not lead to stone formation; only P. mirabilis and S. saprophyticus elevated urinary pH.
Conclusions:
- Proteus mirabilis and Staphylococcus saprophyticus are key etiological agents in the development of infection stones.
- The increase in urinary pH by these bacteria is a critical factor in infection stone pathogenesis.