Related Experiment Videos
Visualization of Proteus mirabilis within the matrix of urease-induced bladder stones during experimental urinary
Xin Li1, Hui Zhao, C Virginia Lockatell
1Department of Microbiology and Immunology, University of Maryland School of Medicine, Veterans Affairs Medical Center, Baltimore, Maryland 21201, USA.
Abstract:
The virulence of a urease-negative mutant of uropathogenic Proteus mirabilis and its wild-type parent strain was assessed by using a CBA mouse model of catheterized urinary tract infection. Overall, catheterized mice were significantly more susceptible than uncatheterized mice to infection by wild-type P. mirabilis. At a high inoculum, the urease-negative mutant successfully colonized bladders of catheterized mice but did not cause urolithiasis and was still severely attenuated in its ability to ascend to kidneys. Using confocal laser scanning microscopy and scanning electron microscopy, we demonstrated the presence of P. mirabilis within the urease-induced stone matrix. Alizarin red S staining was used to detect calcium-containing deposits in bladder and kidney tissues of P. mirabilis-infected mice.
Insights
Uropathogenic Proteus mirabilis causes severe urinary tract infections, especially in catheterized mice. A urease-negative mutant showed reduced virulence, highlighting urease
Area of Science:
- Microbiology
- Urology
- Infectious Diseases
Background:
- Uropathogenic Proteus mirabilis is a significant cause of urinary tract infections (UTIs).
- Urease production by P. mirabilis is a key factor in UTI pathogenesis, contributing to stone formation and inflammation.
Purpose of the Study:
- To evaluate the virulence of a urease-negative mutant of P. mirabilis compared to its wild-type strain.
- To investigate the role of urease in P. mirabilis-induced urolithiasis and kidney colonization in a mouse model.
Main Methods:
- Utilized a CBA mouse model of catheterized urinary tract infection.
- Assessed bacterial colonization, urolithiasis, and kidney infection.
- Employed confocal laser scanning microscopy, scanning electron microscopy, and Alizarin red S staining.
Main Results:
- Catheterized mice were significantly more susceptible to wild-type P. mirabilis infection.
- The urease-negative mutant colonized bladders but did not cause urolithiasis.
- The mutant exhibited significantly attenuated virulence in ascending to the kidneys.
- P. mirabilis was observed within urease-induced stone matrix, and calcium deposits were detected in infected tissues.
Conclusions:
- Urease is critical for P. mirabilis virulence, urolithiasis, and kidney infection.
- The urease-negative mutant is attenuated, offering potential insights into therapeutic strategies.