Min Zhong, Xiangning Huang, Xin Liu, Hua Yu, Shanshan Long

Department of Laboratory Medicine, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, People’s Republic of China

Correspondence: Shanshan Long, Email longss423@163.com Hua Yu, Email yvhua2002@163.com

Objective: To analyze the changes in the distribution and drug resistance of pathogenic bacteria causing urinary tract infections in Southwest China from 2019 to 2023, and to provide an accurate scientific basis for empirical clinical use.
Methods: The identification results and drug susceptibility tests of non-duplicate pathogens isolated from urine samples of patients in Sichuan region from 2019 to 2023 were retrospectively analyzed. The results obtained were interpreted with reference to CLSI M100-33th and analyzed with WHONET 5.6 software.
Results: A total of 247295 strains of pathogens were detected, including 188551 gram-negative strains (76.2%). The positive rate of female patients (56.8%) was significantly higher than that of male patients (43.2%). The top five most common urinary pathogens were Escherichia coli (50.5%), Enterococcus faecium (11.5%), Klebsiella pneumoniae (8.5%), Enterococcus faecalis (6.5%), and Proteus mirabilis (2.9%). The resistance rate of E.coli to levofloxacin, cefotaxime and ceftriaxone was higher (> 50%) and had a certain upward trend. The resistance rates of Klebsiella pneumoniae to imipenem and meropenem increased from 7.8% and 9.6% in 2019 to 11.6% and 13.2% in 2023, respectively, much higher than the resistance rates of E. coli to carbapenem antibiotics (< 2%). E. coli, K. pneumoniae and E. cloacae still maintained high activity against tigecycline and polymyxin B. The drug resistance rate of Acinetobacter baumannii to imipenem and meropenem was more than 27.4%. The resistance rates of Enterococcus faecium and Enterococcus faecalis to vancomycin, teicoplanin and linezolid were lower than 3.4%. There was an increasing trend in the detection of CRE-KPN among multidrug-resistant bacteria, and a slight decreasing trend in CRPA and CRAB.
Conclusion: The main pathogens of urinary tract infections were E. coli, E. faecium and K. pneumoniae. The drug resistance rates of main clinically isolated bacteria in urine samples showed a diverse trend. Antibiotics should be rationally selected based on the resistance patterns of the pathogens. At the same time, with the continuous detection of multi-drug resistant bacteria VRE and CRE, we have a long way to go in future drug resistance monitoring.

Keywords: urinary tract infections, pathogenic bacteria distribution, drug resistance