Predisposing Factors Associated with Third-Generation Cephalosporin-Resistant Escherichia coli in a Rural Community Hospital in Thailand

Background: Various predisposing factors contribute to the emergence and dissemination of the multidrug-resistant (MDR) phenotype in Escherichia coli and Klebsiella pneumoniae. Understanding these factors is crucial for guiding appropriate antimicrobial therapy and infection control strategies. This study investigated the predisposing factors contributing to the MDR characteristics of E. coli and K. pneumoniae isolated in a community hospital in northeastern Thailand. Methods: This case–control study utilized retrospective data from bacterial culture, as well as demographic, clinical, and antibiotic susceptibility records collected during 5 years (January 2016–December 2020). E. coli and K. pneumoniae isolates were analyzed from various clinical samples, including blood, urine, pus, sputum, and other body fluids. Data were analyzed using descriptive statistics and univariate logistic regression. Results: In total, 660 clinical isolates were analyzed (421 E. coli and 239 K. pneumoniae). Blood was the most common source of the detection of E. coli (63.0%) and sputum was the most common source of K. pneumoniae (51.0%). The median ages of patients were 67 and 63 years for E. coli and K. pneumoniae, respectively. E. coli cases were significantly associated with prior antibiotic use (OR = 1.79, 95% CI: 1.17–2.74 p = 0.008). MDR was observed in 50.1% of E. coli and 29.7% of K. pneumoniae (p < 0.001). E. coli compared to K. pneumoniae had lower resistance to third-gen cephalosporins (64.9% versus 95.8%) and carbapenems (8.0% versus 6.9%). ICU admission was the only factor significantly associated with MDR E. coli (OR = 2.40, 95% CI: 1.11–5.20 p = 0.026). No significant differences were observed in gender, age, or comorbidities between MDR cases. Antibiotic usage patterns also differed, with E. coli more likely to receive third-gen cephalosporins compared to carbapenems (OR = 3.02, 95% CI:1.18–7.74 p = 0.021). Conclusions: The use of third-generation cephalosporin may drive MDR E. coli more than K. pneumoniae. Prior antibiotic exposure was linked to E. coli bloodstream infections, while MDR E. coli showed greater clinical severity. These findings highlighted the need for improved antibiotic stewardship in rural hospitals.