Enterococcus faecalis is intrinsic resistance to many drugs. Enterococcus faecalis is usually susceptible to ampicillin and high concentration gentamicin, but combined therapy should be used to achieve curative effect. However, Enterococcus faecium has higher drug resistance and limited treatment options, especially the VRE group. Therefore, monitoring the changes in Enterococcus drug resistance, discovering VRE in time, and achieving an infection control is crucial (6).
This study carried out a multicenter survey of VRE infection nationwide based on CHINET, and the results provide a reference for a comprehensive understanding of the current situation of VRE infection in China.
CHINET was initiated and established by the Institute of Antibiotics of Huashan Hospital affiliated to Fudan University and has been operational for 15 years. A myriad of data on the distribution and drug sensitivity of common bacteria in China released every year provide reference material for the diagnosis and treatment of bacterial infections and the prevention and control of bacterial drug resistance. However, since the data were obtained from all clinical isolates with positive specimens from various hospitals, and some colonized bacteria that were not infected were mixed, the monitoring quality of bacterial drug resistance was affected. According to the case investigation of the host of the isolated strain, distinguishing infection from colonization elucidates the exact situation of Enterococcus infection.
Thus, secondary and tertiary hospitals participated in the survey for the above purpose. Hospitals of different regions and grades in China were selected to explore and analyze the clinical isolates of vancomycin-resistant Enterococcus, and the data on the distribution and drug resistance of VRE pathogenic bacteria were obtained. This information elaborated the current situation of VRE infection in China and provided a crucial basis for the prevention and treatment of VRE infection.
The survey found that the majority of adult patients infected with VRE were men of average old age. Urinary tract infection is the most common type of VRE infection, which is similar to the Enterococcus infection. However, the proportion of severe patients is higher, and the prognosis is poor, which is consistent with that of previous reports (7).
Literature shows that the risk factors of VRE infection include serious primary diseases, long-term hospitalization, admission to ICU, intravenous indwelling catheter, major surgery, and application of broad-spectrum antibacterial drugs (7, 8). The current study showed that in univariate analysis, cardiac insufficiency, mechanical ventilation, dialysis, and other factors are different between VRE and VSE infection. Logistic regression analysis indicated that only indwelling venous catheter is related to VRE infection and should be focused upon in such patients. In addition, VRE infection may occur when empirical vancomycin therapy is ineffective.
VRE often has multidrug resistance, which makes treating the infection challenging. According to the results of the drug sensitivity test, the drug resistance rate of VRE to other antibacterial drugs is higher than that of VSE. The drug resistance rates to linezolid and fosfomycin are 5.7% and 25%, respectively, which are still at a relatively low level and can be used for the treatment of VRE infection. Within the case of urinary tract infection, nearly half of the patients sensitive to furantoin are infected with VRE.
According to the results of this study, patients with VRE infection exhibit severe manifestations and are likely to be admitted to ICU. Although the overall isolation rate of VRE in China is not high, sufficient attention should be paid to such infection, especially for patients with indwelling venous catheters; linezolid, fosfomycin, and other drugs can be selected for treatment.
Nevertheless, the present study has some limitations. Due to the small number of clinically isolated VRE specimens in China, for the samples comprised of 0.4% of Enterococcus faecalis and 1.9% Enterococcus faecium in 2016 (3). Although 20 research centers in the country have been selected based on CHINET, the total number of cases in this study is still small. Thus, expanding the scale and including additional research hospitals will provide a comprehensive understanding of the current situation of VRE infection in China.