Epidemiological Characteristics of Carbapenem-Resistant Escherichia coli Clinically Isolated from a Province in Northern China

Purpose: The purpose of the study is to enquire about the epidemiological characteristics of carbapenem-resistant Escherichia coli clinically isolated strains, and to provide data support for treatment and prevention.

Methods: Drug susceptibility testing was performed using the micro-broth dilution method. The drug sensitivity of strains was evaluated using the Clinical and Laboratory Standards Institute (CLSI, 29th edition M100) standards. Data statistical analysis was completed by the WHONET 5.6 software.

Results: Over the three years from 2017 to 2019, a total of 1439 strains of carbapenem-resistant Escherichia coli were isolated. Among them, urine samples accounted for 33.0% and sputum samples accounted for 29.8%, ranking the top two. Male patients accounted for 57.4%. The number of internal medicine patients was twice that of surgical patients. Elderly (>60 years) and adults (18-59 years) accounted for 59.6% and 30.8% respectively. The isolation rate in provincial capital cities was the highest, reaching 30.92%. The resistance rates of carbapenem-resistant Escherichia coli to cephalosporins, amoxicillin/clavulanic acid, piperacillin/tazobactam, and amikacin were 90.6%, 69.1%, 69.5%, and 22.2% respectively. Among the MIC50/MIC90 values, Tigecycline had the lowest value of 0.5/1
g/ml, while Piperacillin and Piperacillin/tazobactam had the highest value of 128/128
g/ml.

Conclusion: Clinically, carbapenem-resistant Escherichia coli mainly causes urinary and respiratory system infections in the elderly. There are significant regional differences in their distribution, and they exhibit a high resistance rate to
-lactam antibiotics. It is worth noting that tigecycline has lower MIC50 and MIC90 values for this type of resistant Escherichia coli.