Fluoroquinolone Resistance in UTI – Is It Time to Change Drugs?

October 20, 2022

Written by Gabby Leonard

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Fluoroquinolone-resistant (FQR) E. coli was present in 22.1% of UTI pathogens studied at 15 geographically diverse EDs. IDSA guidelines recommend changing empiric treatment if local resistance is >10% and adding a dose of parenteral antibiotic, such as ceftriaxone, prior to discharge home.

Why does this matter?
UTIs comprise over 3 million ED visits per year as well as 15% of total outpatient antibiotic prescriptions. Growing antimicrobial resistance has limited available outpatient treatment regimens.

Fluoroquinolone-resistant UTIs on the rise
This observational cohort study looked at antimicrobial resistance to complicated and uncomplicated UTIs in patients >18 years old across 15 geographically different EDs in the US between 2018-2020. Included patients presented with both symptoms of UTI (dysuria, frequency) and positive urine culture (defined as >10⁴ CFU/mL bacteria with 2 or fewer organisms identified).

Most commonly identified pathogens were E. coli (63.2%), Klebsiella pneumoniae (13.2%) and Enterococcus species (5.8%). Overall, FQR E. coli prevalence was 22.1% (range 10.5-29.7%). Fourteen sites had FQR E. coli >15%, and seven sites were >20%. Resistant pathogens were more commonly identified in complicated pyelonephritis and cystitis when compared to uncomplicated UTI. E. coli resistance was highest to ampicillin (39.2%) and TMP-SMX (24.3%). Additionally, ESBL-producing pathogens were identified in 7.4% of samples.

Investigators identified risk factors for antimicrobial resistance in 44.2% of patients, including oral or IV antibiotics within past 90 days or history of multi-drug resistant pathogens in the past 12 months.  Risk factors were only identified in two-thirds of the patients who were infected with resistant bacteria. By the way, current guidelines recommend nitrofurantoin as first line treatment for uncomplicated cystitis.

Bottom Line: Know your local antimicrobial resistance rates and adjust your UTI therapy accordingly.

Source
High prevalence of fluoroquinolone-resistant UTI among US emergency department patients diagnosed with urinary tract infection, 2018-2020. Acad Emerg Med. 2022 Sep;29(9):1096-1105. doi: 10.1111/acem.14545. Epub 2022 Aug 5.