Trends in Bacterial Distribution and Antimicrobial Resistance in Intensive Care Units of Hubei Province, China: A Four-year Surveillance Study (2020-2023).

Objective: To investigate the distribution characteristics of common bacteria and changes in antimicrobial resistance in intensive care unit (ICU) patients in 58 hospitals in Hubei Province from 2020-2023.

Method: The antimicrobial agents for antimicrobial susceptibility tests was selected based on the 2022 China Antimicrobial Resistance surveillance system (CARSS) technical scheme, and the specific experimental operation was based on the requirements of the CLSI M02 and M07 documents. The commercial instruments were used following the manufacturer's instructions. The interpretation of antimicrobial susceptibility test results was based on the 2023 CLSI M100 standard.

Results: There were 15 585, 19 258, 23 423 and 22 395 clinical isolates in the ICU from 2020 to 2023, respectively. Among them, gram-positive bacteria accounted for 20.5% (3190/15 585), 21.2% (4089/19 258), 21.6% (5067/23 423) and 21.6% (4 831/22 395), respectively. Gram-negative bacteria accounted for 79.5% (12 395/15 585), 78.8% (15 169/19 258), 78.4% (18 356/23 423) and 78.4% (17 564/22 395) of the bacteria, respectively. The top 5 isolates of gram-positive bacteria were Staphylococcus aureus, Enterococcus faecium, Streptococcus pneumoniae, Enterococcus faecalis, Staphylococcus epidermidis and gram-negative bacteria were Klebsiella pneumoniae, Acinetobacter baumannii, Escherichia coli, Pseudomonas aeruginosa and Stenotrophomonas maltophil, respectively, but the proportions and rankings of the isolates in different years slightly differed. The detection rate of methicillin-resistant S. aureus (MRSA) decreased from 44.4% in 2020 to 36% in 2023, and that of methicillin-resistant coagulase-negative Staphylococcus (MRCNS) decreased from 79.8% in 2020 to 73.8% in 2022 and increased to 78.4% in 2023. The detection rates of both vancomycin-resistant E. faecium and E. faecalis were lower than 1%. The detection rate of carbapenem-resistant P. aeruginosa (CRPA) decreased from 25% in 2020 to 19.7% in 2022 and increased slightly to 20.6% in 2023. The detection rate of carbapenem-resistant A. baumannii (CRAB) decreased from 81.9% in 2020 to 79.7% in 2022 and increased to 82.9% in 2023. The detection rate of third-generation cephalosporin-resistant E. coli decreased from 59.8% in 2020 to 53.1% in 2022 and increased to 52.5% in 2023. The detection rate of fluoroquinolone-resistant E. coli decreased from 62.7% in 2020 to 50.2% in 2022 and increased slightly to 51.0% in 2023. The detection rate of carbapenem-resistant E. coli (CRECO) decreased from 3.3% in 2020 to 1.8% in 2022 and slightly increased to 2.1% in 2023. The detection rate of third-generation cephalosporin-resistant K. pneumoniae decreased from 34.3% in 2020 to 26.3% in 2022 and then increased to 32.4% in 2023. The detection rate of carbapenem-resistant K. pneumoniae (CRKPN) increased from 17.9% to 19.4% in 2020, decreased to 13.2% in 2022, and rose sharply to 20.4% in 2023.

Conclusion: MRSA showed a continuous downwards trend from 2020 to 2023, while the detection rates of MRCNS and most multidrug-resistant gram-negative bacteria continuously decreased from 2020 to 2022 but tended to increase in 2023. Therefore, it is still necessary to strengthen the monitoring of bacterial resistance and rational application of antibiotics and actively and effectively control nosocomial infections.