Shifts in hospital-associated pathogens and prevalence trends of carbapenem-resistant Escherichia coli infections, 2021–2023

Introduction: Carbapenem-resistant Escherichia coli (CREC) have emerged as a significant global health threat, particularly in hospital settings, due to their high resistance to critical antibiotics. This study aimed to evaluate the dynamics of pathogenic bacterial isolates in clinical specimens, characterize patients with CREC infections, and identify risk factors for co-infection; in order to strengthen surveillance and infection control measures. Methodology: Clinical specimens were collected from patients at a tertiary hospital in southern Anhui Province between 2021 and 2023. Strain identification and antibiotic susceptibility testing were performed using a time-of-flight mass spectrometry analyzer and the VITEK-2 compact system. Demographic and clinical data were analyzed using rigorous statistical methods. Results: The predominant bacterial species isolated included Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii. Notably, the prevalence of CREC increased from 10.10% in 2021 to 16.36% in 2023. The predominant carbapenem-resistant Enterobacteriaceae (CRE) species were Enterobacter cloacae, Klebsiella pneumoniae, and Escherichia coli; with the proportion of CREC increasing significantly from 10.10% in 2021 to 16.36% in 2023. Of the 81 patients with CREC, 65.43% were over 60 years old. The most common specimen types were urine and sputum, with the highest proportion of patients in the intensive care unit (ICU; 32.10%). Analysis of the co-infected population revealed that ICU patients with tracheal intubation were significant risk factors. Co-infection with carbapenem-resistant Acinetobacter baumannii (CRAB) showed a concerning annual rise. Conclusions: There is urgent need for enhanced surveillance and stringent infection control measures to mitigate the spread of CREC and associated nosocomial infections.