Eight-Year Surveillance of Uropathogenic Escherichia coli in Southwest China

To assess antimicrobial resistance profiles change in uropathogenic Escherichia coli (UPEC) during an 8-year period, especially extended-spectrum β-lactamase (ESBL)-producing and carbapenem-resistant isolates.

A retrospective observational study of urinary tract infections (UTIs) was performed in a territory hospital between 2012 and 2019. Isolates were identified using matrix-assisted laser desorption/ionization time of flight mass spectrometry or the VITEK 2 Compact system. The antimicrobial susceptibility testing was performed using the VITEK 2 Compact system and the modified Kirby-Bauer disc diffusion method.

Of the 7713 non-repetitive UPEC isolates, 7075 (91.7%) were from inpatients and 638 (8.3%) were from outpatients. The prevalence of ESBL declined from 62.5% to 49.7% (P = 0.003). Except for cefoxitin, the resistance rates of ESBL-producing isolates were mostly higher than that of non-ESBL-producing isolates (P < 0.001). The resistance rates of ampicillin (P = 0.013), ampicillin/sulbactam (P = 0.013), ceftriaxone (P < 0.001), gentamycin (P = 0.001), tobramycin (P = 0.011), and trimethoprim/sulfamethoxazole (P = 0.028) declined slightly, while the resistance rate of imipenem increased slightly (P = 0.001). The prevalence of carbapenem-resistant Escherichia coli was <2.0%.

ESBL-producing Escherichia coli is still the main drug-resistant bacteria causing UTIs. We should pay attention to antimicrobial resistance in high-risk inpatient areas and take effective measures to prevent and control nosocomial infections.