Presentations

Abstract

Introduction: Urinary tract infections (UTIs) are among the most prevalent bacterial infections, with an estimated 150 million cases occurring annually worldwide. The rising incidence of antibiotic resistance poses a significant challenge, with studies showing resistance in over 90% of samples to at least one drug and 80% to two or more. Traditional diagnostic methods like standard urine culture (SUC) have been the gold standard for identifying uropathogens and determining antibiotic susceptibility. However, advances in diagnostic techniques such as Polymerase Chain Reaction (PCR) offer higher sensitivity, specificity, and faster results, potentially improving diagnostic accuracy. This study aimed to evaluate the agreement between antibiotic resistance genes (ABR) detected by PCR and antibiotic susceptibility results from SUC within the Hampton Roads community to determine the value of integrating these diagnostic methods for improved patient outcomes.

Methods: This retrospective study analyzed patient data from Urology of Virginia, focusing on individuals who underwent both PCR analysis and SUC between January 1, 2022, and February 23, 2024. The study included patients presenting with persistent or recurrent UTIs or those requiring routine analysis before surgical treatment. Exclusion criteria included patients on antibiotics for reasons other than UTIs or those with an indwelling catheter for more than 10 days. Pooled antibiotic susceptibility testing (P-AST) was conducted on bacteria identified by PCR, and concordance between ABR genes detected by PCR and SUC results was calculated. Data extracted from electronic medical records included bacteria and ABR genes identified by both methods, along with antibiotic sensitivity and bacterial colony counts.

Results: The study analyzed 145 patient charts, with PCR showing positive results in 40.7% of cases and SUC in 41.4%. In 31.7% of cases, both PCR and SUC were positive, and in these instances, antibiotic treatment based on PCR was implemented in 89.13% of cases. Notably, when PCR was positive and SUC was negative, the detected uropathogens were generally more virulent, such as Aerococcus urinae and Corynebacterium. Conversely, when PCR was negative and SUC was positive, the identified uropathogens were often less virulent, including Staphylococcus epidermidis and Enterococcus faecium. This pattern underscores the complementary nature of PCR and SUC: PCR may detect more virulent pathogens that SUC misses, while SUC may identify less pathogenic organisms overlooked by PCR. Additionally, yeast was detected in 3.45% of cases, with PCR identifying specific Candida species. There were also instances where PCR did not detect resistance genes identified by SUC, particularly for antibiotics such as ampicillin, levofloxacin, and ciprofloxacin.

Conclusion: This study demonstrated comparable positive detection rates between PCR and SUC in diagnosing UTIs, highlighting their diagnostic effectiveness. PCR proved valuable in guiding antibiotic treatment due to its rapid and detailed identification of resistance genes, although discrepancies between PCR and SUC results underscore the importance of using both methods. While PCR showed higher sensitivity for detecting certain pathogens, SUC remained essential for identifying less virulent organisms and confirming antibiotic resistance. The integration of PCR and SUC in clinical practice could enhance the accuracy of pathogen detection and antibiotic resistance profiling, ultimately leading to more effective treatment strategies and better patient outcomes.