Antimicrobial resistance patterns and risk factors of Enterococcus faecium bloodstream infections in hospitalized patients in a Chinese tertiary care hospital.

BACKGROUND

Vancomycin-resistant Enterococcus faecium (VR-Efm) has shown a rising global trend. This study aimed to analyze the resistance patterns and risk factors of E. faecium bloodstream infections (BSIs) in hospitalized patients at a Chinese tertiary hospital in Guangzhou, to provide evidence for infection control.

METHODS

This is a retrospective study investigating the antimicrobial susceptibility profiles and clinical characteristics of 48 E. faecium isolates recovered from 48 hospitalized patients (one isolate per patient) between 1st January 2022 and 31st December 2024, with all cases meeting the predefined clinical and microbiological diagnostic criteria for bloodstream infections. For patients with multiple positive blood cultures, only the first isolate was included to avoid duplication bias.

RESULTS

A total of 48 patients with BSIs were included in the final analysis. Among these 48 E. faecium bloodstream isolates, the vancomycin resistance rate was 31.25% (15/48). The proportion of intensive care unit (ICU) patients was significantly higher in the VR-Efm group than in the vancomycin-susceptible E. faecium (VS-Efm) group (73.33% vs. 39.39%, p = 0.029). No significant differences were observed between the two groups regarding underlying comorbidities (hypertension, coronary artery disease, and diabetes mellitus), history of drug/food allergies, surgery, hepatitis, tuberculosis, or blood transfusion (p > 0.05). Moreover, the mortality rate of patients with VR-Efm BSIs was markedly higher than that of those with VS-Efm infections (46.67% vs. 18.18%, p = 0.040). ICU admission (OR = 3.31, 95% CI 1.71-8.48, p = 0.029) and prior exposure to glycopeptides (OR = 7.87, 95% CI 1.21-21.16, p = 0.031) remained independently associated with VR-Efm infection.

CONCLUSION

In this single-center retrospective study, the vancomycin resistance rate among E. faecium bloodstream isolates was 31.25%. ICU admission and prior glycopeptide exposure were identified as independent risk factors for VR-Efm bloodstream infections. Patients with VR-Efm BSIs had significantly higher mortality than those with VS-Efm infections. Although all isolates remained susceptible to linezolid, the high resistance rate and its association with worse clinical outcomes underscore the urgent need for strengthened antimicrobial stewardship, enhanced surveillance, and targeted infection control measures, particularly in ICUs and among patients with prior glycopeptide exposure.