mSphere (Dec 2022)

Genetic Predictive Factors for Nonsusceptible Phenotypes and Multidrug Resistance in Expanded-Spectrum Cephalosporin-Resistant Uropathogenic Escherichia coli from a Multicenter Cohort: Insights into the Phenotypic and Genetic Basis of Coresistance

  • Nicole Jackson,
  • Cheyenne R. Belmont,
  • Nicole J. Tarlton,
  • Yuan Hu Allegretti,
  • Sheila Adams-Sapper,
  • Yolanda Yue Huang,
  • Clarissa A. Borges,
  • Bradley W. Frazee,
  • Danka Florence-Petrovic,
  • Clarisse Hufana,
  • Anna Parker,
  • Claire F. Mastrangelo,
  • Shevya Awasthi,
  • Isha Kane,
  • Zlatan Coralic,
  • Steve Miller,
  • Joycelyn Diaz,
  • Christopher Fee,
  • Cassiana E. Bittencourt,
  • Omai Garner,
  • Sukantha Chandrasekaran,
  • Claudia Crandall,
  • Julian C. Marcha,
  • Mir H. Noorbakhsh,
  • Patricia Rodrigues-Wong,
  • Tara R. deBoer,
  • Lee W. Riley

DOI
https://doi.org/10.1128/msphere.00471-22
Journal volume & issue
Vol. 7, no. 6

Abstract

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ABSTRACT Antimicrobial resistance in urinary tract infections (UTIs) is a major public health concern. This study aims to characterize the phenotypic and genetic basis of multidrug resistance (MDR) among expanded-spectrum cephalosporin-resistant (ESCR) uropathogenic Escherichia coli (UPEC) causing UTIs in California patient populations. Between February and October 2019, 577 ESCR UPEC isolates were collected from patients at 6 clinical laboratory sites across California. Lineage and antibiotic resistance genes were determined by analysis of whole-genome sequence data. The lineages ST131, ST1193, ST648, and ST69 were predominant, representing 46%, 5.5%, 4.5%, and 4.5% of the collection, respectively. Overall, 527 (91%) isolates had an expanded-spectrum β-lactamase (ESBL) phenotype, with blaCTX-M-15, blaCTX-M-27, blaCTX-M-55, and blaCTX-M-14 being the most prevalent ESBL genes. In the 50 non-ESBL phenotype isolates, 40 (62%) contained blaCMY-2, which was the predominant plasmid-mediated AmpC (pAmpC) gene. Narrow-spectrum β-lactamases, blaTEM-1B and blaOXA-1, were also found in 44.9% and 32.1% of isolates, respectively. Among ESCR UPEC isolates, isolates with an ESBL phenotype had a 1.7-times-greater likelihood of being MDR than non-ESBL phenotype isolates (P < 0.001). The cooccurrence of blaCTX-M-15, blaOXA-1, and aac(6′)-Ib-cr within ESCR UPEC isolates was strongly correlated. Cooccurrence of blaCTX-M-15, blaOXA-1, and aac(6′)-Ib-cr was associated with an increased risk of nonsusceptibility to piperacillin-tazobactam, cefepime, fluoroquinolones, and amikacin as well as MDR. Multivariate regression revealed the presence of blaCTX-M-55, blaTEM-1B, and the ST131 genotype as predictors of MDR. IMPORTANCE The rising incidence of resistance to expanded-spectrum cephalosporins among Escherichia coli strains, the most common cause of UTIs, is threatening our ability to successfully empirically treat these infections. ESCR E. coli strains are often MDR; therefore, UTI caused by these organisms often leads to treatment failure, increased length of hospital stay, and severe complications (D. G. Mark, Y.-Y. Hung, Z. Salim, N. J. Tarlton, et al., Ann Emerg Med 78:357–369, 2021, https://doi.org/10.1016/j.annemergmed.2021.01.003). Here, we performed an in-depth analysis of genetic factors of ESCR E. coli associated with coresistance and MDR. Such knowledge is critical to advance UTI diagnosis, treatment, and antibiotic stewardship.

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