Stepwise model to differentiate pathogenic from non-pathogenic organisms in urinary isolates: Effectiveness, safety,...

Area of Science:

• Medical Microbiology
• Clinical Diagnostics
• Infectious Diseases

Background:

• Accurate differentiation of pathogenic and non-pathogenic organisms is crucial for clinical decision-making in urinary tract infections (UTIs).
• Current interpretation of urine cultures relies on sample collection, clinical context, and organism characteristics, lacking a definitive method to identify truly pathogenic isolates.
• Distinguishing pathogenic from non-pathogenic urinary bacteria is critical for appropriate antibiotic treatment strategies.

Purpose of the Study:

• To systematically apply a structured, stepwise model to classify urinary isolates as pathogenic (commensal, colonizer, or direct pathogen) or non-pathogenic (commensal, colonizer, or contaminant).
• To evaluate the feasibility and potential impact of a novel model for differentiating urinary tract infection pathogens.

Main Methods:

• A prospective, longitudinal, exploratory study conducted over 24 months.
• Application of a stepwise model developed by investigators to assess the nature of urinary isolates.
• Data collection via REDCap and analysis using SPSS Version 25.

Main Results:

• The stepwise model classified 90.54% of 275 patients with positive urine cultures as pathogenic and 9.45% as non-pathogenic.
• Pathogenic classifications included commensals (61.81%), colonizers (14.18%), and direct pathogens (14.54%).
• The non-pathogenic cohort demonstrated potential for over 13 days reduction in average hospital stay and cost savings of approximately Rs. 981 per patient in antibiotic expenses.

Conclusions:

• A novel stepwise model identified that approximately 10% of urinary isolates initially treated as pathogenic were non-pathogenic.
• The model is deemed safe, feasible, and potentially valuable, especially in resource-limited settings.
• Broader validation and implementation of this model are warranted to optimize UTI management and antibiotic stewardship.