Infection and Drug Resistance (Aug 2021)

Concordance Between Antibiotic Resistance Genes and Susceptibility in Symptomatic Urinary Tract Infections

  • Baunoch D,
  • Luke N,
  • Wang D,
  • Vollstedt A,
  • Zhao X,
  • Ko DSC,
  • Huang S,
  • Cacdac P,
  • Sirls LT

Journal volume & issue
Vol. Volume 14
pp. 3275 – 3286

Abstract

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David Baunoch,1,2 Natalie Luke,2 Dakun Wang,3 Annah Vollstedt,4 Xinhua Zhao,5 Dicken SC Ko,6 Shuguang Huang,5 Patrick Cacdac,2 Larry T Sirls4 1Research/Development, Pathnostics, Irvine, CA, USA; 2Clinical Affairs, Pathnostics, Irvine, CA, USA; 3Medical Writing, Stat4ward, Pittsburgh, PA, USA; 4Women’s Urology and Pelvic Health Center, Beaumont Hospital, Royal Oak, MI, USA; 5Statistics, Stat4ward, Pittsburgh, PA, USA; 6Department of Bio Med Surgery, Warren Alpert Medical School of Brown University, Providence, RI, USACorrespondence: David Baunoch Email [email protected]: Studies have shown that multiple genes influence antibiotic susceptibility, but the relationship between genotypic and phenotypic antibiotic susceptibility is unclear. We sought to analyze the concordance between the presence of antibiotic resistance (ABR) genes and antibiotic susceptibility results in urine samples collected from patients with symptomatic urinary tract infection (UTI).Patients and Methods: Urine samples were collected from patients presenting to 37 geographically disparate urology clinics across the United States from July 2018 to February 2019. Multiplex polymerase chain reaction was used to detect 27 ABR genes. In samples containing at least one culturable organism at a concentration of ≥ 104 cells per mL, pooled antibiotic susceptibility testing (P-AST), which involves simultaneous growing all detected bacteria together in the presence of antibiotic and then measure susceptibility, was performed against 14 antibiotics. The concordance rate between the ABR genes and the P-AST results was generated for the overall group. The concordance rates for each antibiotic between monomicrobial and polymicrobial infection were compared using chi-square test.Results: Results from ABR gene detection and P-AST of urine samples from 1155 patients were included in the concordance analysis. Overall, there was a 60% concordance between the presence or absence of ABR genes and corresponding antimicrobial susceptibility with a range of 49– 78% across antibiotic classes. Vancomycin, meropenem, and piperacillin/tazobactam showed significantly lower concordance rates in polymicrobial infections than in monomicrobial infections.Conclusion: Given the 40% discordance rate, the detection of ABR genes alone may not provide reliable data to make informed clinical decisions in UTI management. However, when used in conjunction with susceptibility testing, ABR gene data can offer valuable clinical information for antibiotic stewardship.Keywords: urinary tract infection, antibiotic resistance, antibiotic resistance genes, bacteria, culture, antibiotic susceptibility test, polymerase chain reaction

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