Trends in antimicrobial resistance in bloodstream infections at a large tertiary-care hospital in China: a 10-year retrospective study (2010-2019).

OBJECTIVES: Bloodstream infections (BSIs) are a major cause of morbidity and mortality worldwide. This study aimed to explore the distribution and antimicrobial resistance of BSI pathogens at a tertiary-care hospital in China. METHODS: Surveillance blood cultures were routinely taken from patients with fever or suspected sepsis from 2010-2019 at the First Affiliated Hospital of Zhengzhou University. Isolate identification was performed by VITEK®2 Compact and/or VITEK® MS. Antimicrobial susceptibility testing was carried out by MIC determination and/or disk diffusion. RESULTS: Totally, 18 180 strains were isolated from blood cultures, the most common being Escherichia coli (21.7%), followed by coagulase-negative staphylococci (CoNS) (18.8%), Klebsiella pneumoniae (13.0%) and Staphylococcus aureus (6.6%). Escherichia coli resistance rates to ceftazidime, ceftriaxone, cefepime and aztreonam showed a significant declining trend, and the frequency of carbapenem-resistant E. coli was <6.0% over time. Noteworthy, the proportion of carbapenem-resistant K. pneumoniae exhibited a sharp upward trend (from 6.7% to 56.7%). The prevalence of carbapenem-resistant A. baumannii remained at a high level (>75%). Pseudomonas aeruginosa resistance rates against all tested agents were <25%, and resistance rates to aminoglycosides and fluoroquinolones showed a significant downward trend. The frequency of methicillin-resistant CoNS maintained a high level (>70%), however the isolation rate of MRSA ranged from 58.0% to 34.7%, showing a significant decline. CONCLUSION: The dramatic increase in carbapenem-resistant K. pneumoniae during 10 years was noteworthy. Effective infection control measures and stewardship efforts should be taken to prevent their spread. Our results indicate the importance of active surveillance for aetiology and resistance of BSI isolates.