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@#Abstract: Objective To analyze the distribution and drug resistance evolution characteristics of pathogenic bacteria of bloodstream infection in nine tertiary hospitals in Yunnan Province from 2017 to 2021, so as to provide reliable basis for rational selection of antibiotics in clinic. Methods Using the drug sensitive paper method or instrument method, the bacteria identification and drug sensitivity test were carried out in nine tertiary hospitals in different regions according to the unified technical scheme. The results were judged according to the Clinical and Laboratory Standards Institute (CLSI) breakpoint standard in 2021, and use WHONET5.6 for data statistical analysis. Results A total of 12 003 strains of pathogenic bacteria were isolated from bloodstream infection samples in the past five years, including 7 442 strains of Gram-negative bacteria (62.0%) and 4562 strains of Gram-positive bacteria (38.0%), with an increasing trend in the number of isolated strains; of these, 163 strains (1.4%) were isolated from outpatients and 11 840 strains (98.6%) were isolated from inpatients. The top three gram-negative bacteria were Escherichia coli, Klebsiella pneumoniae and Acinetobacter baumannii, of which 309 strains (4.2%) were carbapenem-resistant Klebsiella pneumoniae (CR-KPN), 29 strains (0.4%) carbapenem-resistant Escherichia coli and 19 strains (0.3%) carbapenem-resistant Enterobacter cloacae, and the number of CR-KPN was on the rise year by year. The top three Gram-positive bacteria were coagulase-negative staphylococci, Staphylococcus aureus and Enterococcus faecium, of which methicillin-resistant Staphylococcus aureus (MRSA) was detected for 213 strains, accounting for 27.7%, and decreased from 40.0% in 2017 to 23.4% in 2021, showing a downward trend year by year. No vancomycin-resistant staphylococci and enterococci were found. Conclusions The detection and composition of bloodstream infection pathogenic bacteria in multicenter have not changed much in the past five years, but each hospital has its own characteristics. The number of carbapenem resistant Enterobacteriaceae increased year by year, which should be paid more attention.
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The supramolecular interaction between the water-soluble pillar[5]arene (WP[5]) as host and dopamine hydrochloride (DH) as guest was studied by spectrofluorometry. The fluorescence intensity of DH gradually decreased with increasing WP[5] concentration, and the possible interaction mechanism between WP[5] and DH was confirmed by 1H NMR, 2D NOESY, and molecular modelling. Based on significant DH fluorescence, a highly sensitive and selective method for DH determination was developed for the first time. The fluorescence intensity was measured at 312nm, with excitation at 285nm. The effects of pH, temperature, and reaction time on the fluorescence spectra of the WP[5]-DH complex were investigated. A linear relationship between fluorescence intensity and DH concentration in the range of 0.07-6.2µgmL-1 was obtained. The corresponding linear regression equation is ΔF=25.76 C+13.56 (where C denotes the concentration in µgmL-1), with the limit of detection equal to 0.03µgmL-1 and the correlation coefficient equal to 0.9996. This method can be used for the determination of dopamine in injection and urine samples. In addition, the WP[5]-DH complex has potential applications in fluorescent sensing and pharmacokinetics studies of DH.
