Molecular Characterization of Virulence Factors in Escherichia coli Isolated from Elderly Patients with Urinary Tract Infection

Introduction: Urinary tract infections (UTIs) in elderly patients represent a major clinical challenge due to their high frequency, their often atypical presentation, and the potential complications that can arise in this vulnerable population. Objective: The aim of this study was the molecular characterization of virulence factors in Escherichia coli isolated from UTI patients over 50 years of age. Materials and Methods: The methods used included phenotypic identification of 80 strains by conventional microbiological techniques, thus confirming their 100% identity. In addition, molecular characterization was performed by PCR to detect the fimH and hlyA virulence genes, while antibiotic susceptibility testing was carried out. The results show that 80% of strains come from outpatient clinics and 20% from urology departments. Moreover, 74% of patients were male, compared with 26% female. High rates of antibiotic resistance were observed: 73.75%, 81.5% and 78.75% respectively for amoxicillin/clavulanic acid, cefepime and ceftriaxone. Strains tested against ciprofloxacin showed a high resistance rate of 78.57%. With regard to virulence genes, 80% of strains had the fimH gene, but none had the hlyA gene. Conclusion: These results underline the importance of the fimH gene in urinary tract infections in the elderly, and suggest appropriate therapeutic management.