Related Experiment Videos
Properties of a deep Proteus R mutant isolated from clinical material
D Krajewska-Pietrasik1, A Rózalski, B Bartodziejska
1Institute of Microbiology, University of Lódź, Poland.
Abstract:
Some biological features of a deep P. mirabilis 17301 R mutant isolated from the urine of a patient with chronic UTI were studied and compared with similar features of P. mirabilis S forms and five induced Proteus R mutants of different chemotypes. There were no differences in lethal toxicity and adhesion to human uroepithelial cells. Of all the R mutants tested, two of them, 17301 and R4, exhibited strong cell-bound hemolytic activity. The P. mirabilis R 17301 was characterized as the most invasive (tested in L929 mouse fibroblasts) compared to the other Proteus S and R forms. The structure of PS from a clinical R mutant investigated and the results of serological studies prove that this mutant belongs to the Rc chemotype.
Insights
This study investigated a Proteus mirabilis R mutant from chronic urinary tract infections (UTI). The mutant showed high hemolytic activity and invasiveness, differing from other strains.
Area of Science:
- Microbiology
- Urology
- Infectious Diseases
Background:
- Proteus mirabilis (P. mirabilis) is a common cause of urinary tract infections (UTIs).
- R mutants of P. mirabilis may exhibit altered virulence factors compared to smooth (S) forms.
- Understanding P. mirabilis R mutant characteristics is crucial for managing chronic UTIs.
Purpose of the Study:
- To characterize the biological features of a P. mirabilis R mutant (17301) isolated from a patient with chronic UTI.
- To compare these features with P. mirabilis S forms and other induced Proteus R mutants.
- To determine the chemotype of the clinical R mutant.
Main Methods:
- Isolation and characterization of a P. mirabilis R mutant from patient urine.
- Comparative analysis of lethal toxicity, uroepithelial cell adhesion, and hemolytic activity.
- Invasion assays using L929 mouse fibroblasts.
- Structural investigation of polysaccharide (PS) and serological studies for chemotype determination.
Main Results:
- No significant differences in lethal toxicity or uroepithelial cell adhesion were observed between the R mutant and S forms.
- Two R mutants, including 17301, displayed strong cell-bound hemolytic activity.
- P. mirabilis R 17301 demonstrated the highest invasiveness among tested Proteus strains.
- Structural and serological analyses confirmed the clinical R mutant belongs to the Rc chemotype.
Conclusions:
- The P. mirabilis R 17301 mutant possesses distinct virulence properties, including enhanced invasiveness and hemolytic activity.
- Despite shared toxicity and adhesion profiles, R mutants can exhibit unique pathogenic mechanisms.
- The Rc chemotype designation provides further classification for this clinically relevant P. mirabilis strain.