Molecular Characterization of Adhesions and Fimbriae in Proteus Mirabilis Associated with Urinary Tract Colonization : A Genomic Approach

Abstract

Background: Proteus mirabilis is a significant causative agent of complicated urinary tract infections (UTIs), especially in catheterized patients. The bacterial adhesins and fimbriae, such as mannose-resistant Proteus-like (MR/P) fimbriae, play a critical role in mediating attachment to the uroepithelium, influencing the clinical course of infection. Variations in these adhesins may lead to differences in infection severity.

Objective: This prospective study aims to analyze the adhesion potential and fimbrial expression in P. mirabilis strains from a sample of 100 patients with complicated UTIs, correlating these factors with clinical outcomes.

Methods: A total of 100 clinical isolates of P. mirabilis were collected and categorized based on their adhesive capabilities to uroepithelial cells. Fimbrial gene expression was quantified using PCR, while biofilm formation and motility assays were performed. The correlation between adhesion potential and clinical outcomes was also evaluated.

Results: Of the 100 strains, 62% were classified as high-affinity (HA) and 38% as low-affinity (LA) strains. High-affinity strains showed significantly higher expression of MR/P fimbriae, enhanced biofilm formation, and greater motility. Clinical outcomes, including infection recurrence and treatment resistance, were worse in patients infected with HA strains.

Conclusion: The differential expression of adhesins and fimbriae in P. mirabilis strains plays a pivotal role in their pathogenicity, with high-affinity strains linked to more severe clinical outcomes. This study provides insight into potential therapeutic targets for reducing the risk of recurrent and complicated UTIs.