Phenotypic ESBL and AmpC in community-acquired urinary tract infections in Babylon, Iraq: Empirical therapy mismatch and clinical outcomes

Yasameen Riyadh Saeed  Al-Azzawi; Thanaa Abdulmahdi  Mokif; Fakhri  Alajeel; Tahreer Hadi  Saleh

doi:10.31450/ukrjnd.3(91).2026.06

Yasameen Riyadh Saeed Al-Azzawi Department of Community Health Techniques, College of Health and Medical Technologies, University of Hilla, Babylon, Iraq https://orcid.org/0009-0003-9123-9913
Thanaa Abdulmahdi Mokif Babylon Technical Institute, Al-FuratAl-Awsat Technical University, Babylon, Iraq https://orcid.org/0000-0002-9661-8280
Fakhri Alajeel Department of Medical Laboratory Technology, College of Technical, Al-Hadi University, Baghdad, Iraq https://orcid.org/0000-0002-3317-7465
Tahreer Hadi Saleh Department of Biology, College of Science, University of Mustansiriyah, Baghdad, Iraq https://orcid.org/0000-0001-7945-7609

DOI: https://doi.org/10.31450/ukrjnd.3(91).2026.06

Keywords: urinary tract infections, community-acquired infections, beta-lactamases, drug resistance, Escherichia coli, Klebsiella pneumoniae, treatment failure, recurrence.

Abstract

Community-acquired urinary tract infections (UTI) are commonly treated empirically before culture and susceptibility results are available. The rising prevalence of extended-spectrum beta-lactamase (ESBL) and AmpC beta-lactamase phenotypes in uropathogens could lead to decreased effectiveness of empiric treatment and higher incidence of treatment failure and recurrence. The present study was carried out to investigate the prevalence of phenotypic ESBL and AmpC-producing community-acquired UTIs caused by E. Coli and K. Pneumoniae in Babylon, Iraq, and to determine their association with empirical therapy mismatch and clinical outcomes.

Methods. This multicenter observational cohort study included 150 episodes of symptomatic community-acquired UTIs caused by E. coli or K. pneumoniae. ESBL and AmpC production were detected phenotypically. Empirical therapy mismatch was defined as initial antibiotic therapy that was inactive against the isolated organism according to susceptibility testing. Outcomes included treatment failure within 14 days and recurrence within 30 and 90 days. Logistic regression was used to assess predictors of empirical therapy mismatch and treatment failure.

Results. ESBL production was detected in 44 isolates (29.3%), AmpC production in 16 isolates (10.7%), and ESBL and/or AmpC positivity in 54 isolates (36.0%). Six isolates were positive for both ESBL and AmpC phenotypes. Multidrug resistance was detected in 48 isolates (32.0%). Empirical therapy mismatch occurred in 42 episodes (28.0%). In multivariable logistic regression, ESBL phenotype was independently associated with empirical therapy mismatch (aOR 4.10, 95% CI 1.90–8.90; p < 0.001), as was prior antibiotic exposure within 90 days (aOR 2.05, 95% CI 1.00–4.20; p = 0.049). Empirical therapy mismatch was independently associated with treatment failure within 14 days (aOR 3.02, 95% CI 1.20–7.60; p = 0.019). ESBL/AmpC-positive infections also showed higher rates of treatment failure, antibiotic escalation, and recurrence.

Conclusions. Phenotypic ESBL and AmpC production were common among community-acquired E. coli and K. pneumoniae urinary isolates in Babylon, Iraq. Empirical therapy mismatch occurred in more than one-quarter of cases and was associated with poorer short-term outcomes. Our findings support local antibiogram-guided, risk-stratified empirical therapy with early culture-directed adjustment.