Abstract: Objective To investigate the distribution of pathogenic bacteria and the trend of drug resistance in hospitalized elderly patients, so as to provide reference for rational clinical use of drugs. Methods Pathogenic bacteria were collected from Jan. 2012 to Dec. 2021 in elderly patients hospitalized in the Affiliated Hospital of Binzhou Medical University. The annual trend of drug resistance rate of major pathogenic bacteria was analyzed with Cochran-Armitage trend test. Results A total of 12 258 pathogenic bacteria were isolated, of which Gram-negative bacteria accounted for 81.7%, and Escherichia coli(19.7%)was the most common; Gram-positive bacteria accounted for 18.3%, the most common being Staphylococcus aureus(5.7%). 22.5% of the pathogenic bacteria were isolated from the intensive care unit and 55.0% from sputum specimens. Resistance rates to carbapenems in Escherichia coli and Klebsiella pneumoniae were below 3%. 10.2% to 21.8% of Pseudomonas aeruginosa were resistant to carbapenems over a 10-year period. Although the resistance rate of Acinetobacter baumannii to carbapenems was generally declining, it was still above 40% in 2021. The detection rate of methicillin-resistant Staphylococcus aureus ranged from 18.8% to 44.7% over the 10-year period, and two vancomycin-resistant strains of Staphylococcus aureus and three vancomycin-resistant strains of Enterococcus faecalis were detected during this period. Conclusion It is recommended that hospitals should continuously monitor pathogenic bacteria for rational use of antibacterial drugs in clinic.

Key words: Elderly inpatients, Pathogenic bacteria, Antibacterial drugs, Drug resistance