Objective To study the risk factors and strain resistance of Escherichia coli with extended-spectrum β-lactamases(ESBL)-producing bloodstream infection,so as to provide clinical basis for rational use of antibiotics and effective prevention and control of bloodstream infection.Methods The clinical data of patients with bloodstream infections caused by Escherichia coli in a tertiary hospital in Chongqing from January 2018 to December 2022 were retrospectively collected.The clinical characteristics and drug resistance of bloodstream infections caused by Escherichia coli were statistically analysed.According to the ESBL confirmation test of Escherichia coli strains,the patients were divided into the ESBL-producing group and the non-ESBL-producing group.The chi-square test was used to compare the differences in influencing factors between the two groups,and then the independent influencing factors of ESBL production were analyzed through multivariate Logistic regression.Results A total of 408 patients were included.The detection rate of ESBL-producing strains was 60.3％(246/408),and the detection rates in the nephrology department and the intensive care unit were relatively high(both＞76.0％).Diabetes[OR=1.98,95％CI(1.24,3.17)]and urinary tract intubation[OR=1.60,95％CI(1.02,2.51)]were independent influencing factors for bloodstream infection with ESBL-producing Escherichia coli.The resistance rate of ESBL-producing Escherichia coli to levofloxacin and ceftriaxone was＞90.0％.Moreover,the resistance rates of the second-generation cephalosporins(except ceftazidime),compound sulfamethoxazole,ciprofloxacin and amtronam were significantly higher than those in the non-ESBL-producing group(P＜0.05).Both groups of strains showed high sensitivity to amikacin and carbapenem drugs.Conclusion The severe current situation of bloodstream infections caused by ESBL-producing Escherichia coli in this region showing a high prevalence of drug resistance characteristics.Diabetes and urinary tract intubation,as independent risk factors,suggest that key monitoring should be implemented for such high-risk populations in clinical practice.Given that ESBL-producing strains remain sensitive to carbapenems and amikacin,it can be recommended as the first empirical medication.It is of great public health significance to achieve the effect of curbing the spread of such multi-drug resistant bacteria by establishing an early warning system based on risk factor assessment and standardized management of invasive operations.

Exosome-based liquid biopsy technology,with its unique advantages,has demonstrated signifi-cant application potential in the field of tumor diagnosis and treatment.This article aims to outline the basic characteristics of exosomes,their extraction and identification techniques,and focuses on the latest research progress of exosomes in the field of tumor diagnosis and treatment.Current studies indicate that the quantity,size of exosomes,and the biomarkers they carry are of great clinical value in achieving personalized medicine,improving the accuracy of early diagnosis,monitoring treatment effects,and assessing prognosis.These aspects hold profound significance for advancing the development of precision medicine in tumors.Although there are still certain challenges in the standardization of exosome isolation and purification,and the diversity of sample processing,with ongoing research and continuous technological development,exosomes are expected to play an even more important role in the field of tumor diagnosis and treatment.

Objective To study the risk factors and strain resistance of Escherichia coli with extended-spectrum β-lactamases(ESBL)-producing bloodstream infection,so as to provide clinical basis for rational use of antibiotics and effective prevention and control of bloodstream infection.Methods The clinical data of patients with bloodstream infections caused by Escherichia coli in a tertiary hospital in Chongqing from January 2018 to December 2022 were retrospectively collected.The clinical characteristics and drug resistance of bloodstream infections caused by Escherichia coli were statistically analysed.According to the ESBL confirmation test of Escherichia coli strains,the patients were divided into the ESBL-producing group and the non-ESBL-producing group.The chi-square test was used to compare the differences in influencing factors between the two groups,and then the independent influencing factors of ESBL production were analyzed through multivariate Logistic regression.Results A total of 408 patients were included.The detection rate of ESBL-producing strains was 60.3％(246/408),and the detection rates in the nephrology department and the intensive care unit were relatively high(both＞76.0％).Diabetes[OR=1.98,95％CI(1.24,3.17)]and urinary tract intubation[OR=1.60,95％CI(1.02,2.51)]were independent influencing factors for bloodstream infection with ESBL-producing Escherichia coli.The resistance rate of ESBL-producing Escherichia coli to levofloxacin and ceftriaxone was＞90.0％.Moreover,the resistance rates of the second-generation cephalosporins(except ceftazidime),compound sulfamethoxazole,ciprofloxacin and amtronam were significantly higher than those in the non-ESBL-producing group(P＜0.05).Both groups of strains showed high sensitivity to amikacin and carbapenem drugs.Conclusion The severe current situation of bloodstream infections caused by ESBL-producing Escherichia coli in this region showing a high prevalence of drug resistance characteristics.Diabetes and urinary tract intubation,as independent risk factors,suggest that key monitoring should be implemented for such high-risk populations in clinical practice.Given that ESBL-producing strains remain sensitive to carbapenems and amikacin,it can be recommended as the first empirical medication.It is of great public health significance to achieve the effect of curbing the spread of such multi-drug resistant bacteria by establishing an early warning system based on risk factor assessment and standardized management of invasive operations.