A Diagnostic Test Combining Molecular Testing with Phenotypic Pooled Antibiotic Susceptibility Improved the Clinical Outcomes of Patients with Non-E. coli or Polymicrobial Complicated Urinary Tract Infections

Abstract

Purpose

Complicated UTIs (cUTIs) cause significant morbidity and healthcare resource utilization and cost. Standard urine culture has limitations in detecting polymicrobial and non-E. coli infections, resulting in the under-diagnosis and under-treatment of cUTIs. In this study, patient-reported outcomes were compared between treated and untreated patients when an advanced diagnostic test combining multiplex-polymerase chain reaction (M-PCR) with a pooled antibiotic susceptibility method (P-AST) was incorporated into the patients’ clinical management.

Methods

Patients who had symptoms typical of cUTI and positive M-PCR/P-AST test results were recruited from urology clinics. Symptom reduction and clinical cure rates were measured from day 0 through day 14 using the American English Acute Cystitis Symptom Score (ACSS) Questionnaire. Clinical cure was defined based on the sum of the scores of four US Food and Drug Administration (FDA) symptoms and the absence of visible blood in the urine.

Results

Of 264 patients with suspected cUTI, 146 (55.4%) had exclusively non-E. coli infections (115 treated and 31 untreated) and 190 (72%) had polymicrobial infections (162 treated and 28 untreated). Treated patients exhibited greater symptom reduction compared to untreated ones on day 14 for those with exclusively non-E. coli organisms (3.18 vs 1.64, p = 0.006) and polymicrobial infections (3.52 vs 1.41, p = 0.002), respectively. A higher percentage of treated patients than of untreated patients achieved clinical cure for polymicrobial infections on day 14 (58.7% vs 36.4%, p = 0.049).

Conclusion

Patients with cUTIs treated based on the M-PCR/P-AST diagnostic test had significantly improved symptom reduction and clinical cure rates compared to untreated patients among those with non-E. coli or polymicrobial infections.

Keywords:

• urinary tract infection
• complicated urinary tract infection
• antibiotic
• clinical outcome
• diagnostic testing
• polymerase chain reaction

Abbreviations

ASCC, Acute Cystitis Symptom Score; cUTIs, Complicated UTIs; ED, emergency department; M-PCR, multiplex-polymerase chain reaction; P-AST, pooled antibiotic susceptibility method; SD, standard deviation; SUC, standard urine culture; UTIs, Urinary tract infections.

Data Sharing Statement

All relevant data are present within the manuscript text and Tables.

Ethics Approval and Consent to Participate

All patients provided verbal informed consent (Western IRB 20214705) prior to enrollment.

Disclosure

D.B., N.L., and M.M. are employees of Pathnostics, and D.W. and X.Z. are paid consultants of Pathnostics. Dr Howard J Korman is a Scientific Advisory Board member and Consultant for Pathnostics. Dr David Baunoch has a patent US 10,160,991 issued to PATHNOSTICS, a patent US 11,053,532 issued to PATHNOSTICS, a patent US 17/178,091 pending to PATHNOSTICS, a patent US 17/335,767 pending to PATHNOSTICS, a patent US 17/830,227 pending to PATHNOSTICS, a patent PCT/US22/16816 pending to PATHNOSTICS, a patent PCT/US22/77477 pending to PATHNOSTICS. The authors report no other conflicts of interest in this work.

Additional information

Funding

Pathnostics and Thermo Fisher funded the study.