Temporal Shifts in Etiological Agents and Trends in Antimicrobial Resistance of Bloodstream Infection in Southwest China from 2016 to 2023.

Abstract

Objective: The purpose of this study was to assess the frequency distribution of bacterial pathogens causing bloodstream infections (BSIs) as well as the characteristics of antibiotic susceptibility and resistance to gain a deeper understanding of the drug resistance situation in the southwest China.

Methods: Non-duplicate pathogenic bacteria according to the American Clinical and Laboratory Standards Institute (CLSI) M100 and analyzed using WHONET 5.6 software.

Results: A total of 170,246 non-duplicated pathogenic bacteria were isolated from blood from 2016 to 2023. Gram-negative bacteria accounted for 59.5% and Gram-positive bacteria accounted for 40.5%. The top five detection rates were Escherichia coli (33.9%), coagulase-negative staphylococci (21.7%), Klebsiella pneumoniae (11.5%), Staphylococcus aureus (7.0%), and Enterococcus spp (5.4%). Streptococcus pneumoniae, Salmonella spp and β-Hemolytic Streptococcus were significantly more frequently isolated in pediatric patients than in adult patients. The rate of resistance to carbapenems was less than 1.2% in the Escherichia coli over the 8-year period, with a significant upward trend in the Klebsiella pneumoniae. The overall resistance rate of Pseudomonas aeruginosa to imipenem and meropenem had a slow decreasing trend. The resistance rate of Acinetobacter baumannii to imipenem and meropenem has been maintained at a high level, which is greater than 50%. The detection rate of MRSA was 27.70% and vancomycin- and linezolid-resistant strains were not found. The resistance rates of Enterococcus faecium and Enterococcus faecalis to vancomycin, linezolid and teicoplanin were less than 2.1%.

Conclusion: The pathogenic bacteria of bloodstream infection in southwest China were diversified, and the multi-drug resistant bacteria, especially Carbapenem-resistant Klebsiella pneumoniae (CRKP), had increased significantly, posing a serious challenge to clinical treatment. Additionally, the situation of Methicillin-resistant Staphylococcus aureus (MRSA) and Vancomycin-resistant Enterococcus (VRE) also required close attention.