Extended-Spectrum β-Lactamase Positivity and 10-Year Resistance Trends in Escherichia coli and Klebsiella pneumoniae Isolates Causing Community-Acquired Urinary Tract Infections Toplum Kökenli Üriner Sistem İnfeksiyonu Etkeni Escherichia coli ve Klebsiella pneumoniae İzolatlarında Genişlemiş Spektrumlu β-Laktamaz Pozitifliği ve 10 Yıllık Direnç Değişimi
Klimik Dergisi, cilt.39, sa.2, ss.99-105, 2026 (ESCI, Scopus, TRDizin)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 39 Sayı: 2
- Basım Tarihi: 2026
- Doi Numarası: 10.36519/kd.2026.5361
- Dergi Adı: Klimik Dergisi
- Derginin Tarandığı İndeksler: Emerging Sources Citation Index (ESCI), Scopus, CAB Abstracts, CINAHL, EMBASE, TR DİZİN (ULAKBİM), Academic Search Ultimate (EBSCO), Biomedical Reference Collection: Corporate Edition (EBSCO), Health Research Premium Collection (ProQuest)
- Sayfa Sayıları: ss.99-105
- Anahtar Kelimeler: community-acquired urinary tract infections, Escherichia coli, extended-spectrum β-lactamase, Klebsiella pneumoniae
- Açık Arşiv Koleksiyonu: AVESİS Açık Erişim Koleksiyonu
- Ondokuz Mayıs Üniversitesi Adresli: Evet
Özet
Objective: Community-acquired urinary tract infections (CA-UTIs) are common bacterial infections most frequently caused by Escherichia coli and Klebsiella pneumoniae. The present study evaluated extended-spectrum β-lactamase (ESBL) positivity rates, antibiotic resistance profiles, and 10-year trends in resistance among adult patients with CA-UTIs caused by E. coli and K. pneumoniae. Methods: This retrospective study evaluated adult outpatients admitted to Ondokuz Mayıs University Medical Faculty Hospital between January 1, 2014, and December 31, 2023, whose urine cultures yielded ≥10⁵ colony-forming units (CFU)/mL of E. coli or K. pneumoniae. Antimicrobial susceptibility testing was performed using the VITEK® 2 Compact system (bioMérieux, Marcy l’Etoile, France), and the results were interpreted according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria. ESBL positivity was defined according to the “presumed ESBL phenotype” approach described in the Clinical and Laboratory Standards Institute (CLSI) M100 guideline. Results: A total of 5168 isolates were evaluated. Of the isolates, 83.5% (n=4316) were E. coli and 16.5% (n=852) were K. pneumoniae. The overall ESBL positivity rate was 28.9%. ESBL positivity was detected in 27% of E. coli isolates and 38.4% of K. pneumoniae isolates (p<0.001). A significant increase in the proportion of K. pneumoniae isolates was ob-served during the second 5-year study period (p<0.001). Resistance rates to ceftriaxone, ceftazidime, and second-gen-eration cephalosporins were high in both pathogens. Ciprofloxacin resistance was 44.3% in E. coli isolates and 33.6% in K. pneumoniae isolates. Nitrofurantoin resistance was low in E. coli isolates (3.0%) but high in K. pneumoniae isolates (39.2%). In addition, carbapenem resistance in K. pneumoniae isolates increased markedly over the years. Conclusion: Our study demonstrated that ESBL positivity and antimicrobial resistance rates among E. coli and K. pneumoniae isolates causing CA-UTIs increased over time. In particular, increases in ESBL positivity and carbapen-em resistance among K. pneumoniae isolates are progressively limiting empirical treatment options. Therefore, regular reassessment of empirical treatment approaches based on current local resistance data is critical.