# P-2078. Escherichia coli Antimicrobial Resistance Risk Differences by Patient Demographics and Insurance Status in Rural Wisconsin

## TL;DR

The study found that patient demographics and insurance status are linked to Escherichia coli antimicrobial resistance in rural Wisconsin.

## Contribution

This research identifies demographic and insurance-related factors associated with E. coli antimicrobial resistance in a rural population.

## Key findings

- Children and females were less likely to have non-susceptible E. coli isolates.
- Hispanic and non-white patients, as well as those with public insurance, had higher odds of E. coli non-susceptibility.
- Antibiotic non-susceptibility increased from 2019 to 2024 across all tested antibiotics.

## Abstract

Our prior research demonstrated Escherichia coli antimicrobial resistance differences at a neighborhood level from 2009 to 2018. As a first step in explaining this variation, we investigated patient factors relating to antimicrobial resistance.Figure.Patient Demographics and Insurance Status Predict E. coli Non-susceptibility to Antibiotics: Results from Multivariable Logistic Regression Models

Patient Demographics and Insurance Status Predict E. coli Non-susceptibility to Antibiotics: Results from Multivariable Logistic Regression Models

We conducted a retrospective analysis of patient demographics and E. coli antibiotic susceptibility from 2019 – 2024. Patients with a culture positive for E. coli and antibiotic susceptibility results at the Marshfield Clinic Health System were included. Patient-level variables analyzed included age, sex, race and ethnicity, type of insurance (public/private), farm residence (yes/no), and year of culture. We conducted logistic regression with generalized estimating equations analyses to identify predictors of E. coli susceptibility vs non-susceptibility (intermediate or resistant) to ciprofloxacin (CIP), nitrofurantoin (FM), trimethoprim/sulfamethoxazole (SXT), and ceftriaxone (CRO) as an indicator extended-spectrum beta-lactamase presence.

Regression results are presented in the Figure. Compared to adults 18 to 64 years, children were significantly less likely to have E. coli non-susceptible to CIP and CRO. Older adults (≥65 years) were less likely to have E. coli non- susceptible to SXT but more likely to have E. coli non-susceptible to CIP and CTX compared to younger adults. Females were less likely to have E. coli non-susceptible to CIP and CRO than males. Compared to white patients, odds of E. coli non-susceptibility were higher for Hispanic (CIP, SXT, and FM) and non-white patients (CIP and SXT). Public insurance was a predictor of E. coli non-susceptibility to CIP and FM. Odds of non-susceptibility were higher in 2024 compared to 2019 for all antibiotics. Of 36,043 unique E. coli isolates, 1,642 (4.6%) were from farm-residing patients; however, farm residence was not significantly associated with E. coli susceptibility in multivariable models.

Children and female patients were at lower risk for non-susceptible E. coli. The risk of non-susceptibility was lower for SXT, and higher for CIP and CTX in older adults. Hispanic and non-white patients, and patients with public health insurance had greater risk for E. coli non-susceptibility.

Maria Sundaram, PhD, MSPH, GSK: Grant/Research Support Joshua Petrie, PhD, CSL Seqirus: Advisor/Consultant|CSL Seqirus: Grant/Research Support|ModernaTX: Grant/Research Support