RESUMO
A new C3-symmetric Schiff-base fluorescent probe (L) based on 8-hydroxy-2-methylquinoline has been developed. As expected, the probe L can display high fluorescent selectivity for Cd(2+) over Zn(2+) and most other common ions in neutral ethanol aqueous medium. Moreover, the mechanism of the L-Cd(2+) complex has been confirmed by X-ray crystallography and density functional theory calculation results. More importantly, L could be used to image Cd(2+) within living cells.
Assuntos
Cádmio/análise , Corantes Fluorescentes/química , Oxiquinolina/análogos & derivados , Bases de Schiff/química , Poluentes Químicos da Água/análise , Cátions Bivalentes/análise , Cristalografia por Raios X , Modelos Moleculares , Oxiquinolina/química , Espectrometria de FluorescênciaRESUMO
Objective: To explore the genotyping characteristics of human fecal Escherichia coli( E. coli) and the relationships between antibiotic resistance genes (ARGs) and multidrug resistance (MDR) of E. coli in Miyun District, Beijing, an area with high incidence of infectious diarrheal cases but no related data. Methods: Over a period of 3 years, 94 E. coli strains were isolated from fecal samples collected from Miyun District Hospital, a surveillance hospital of the National Pathogen Identification Network. The antibiotic susceptibility of the isolates was determined by the broth microdilution method. ARGs, multilocus sequence typing (MLST), and polymorphism trees were analyzed using whole-genome sequencing data (WGS). Results: This study revealed that 68.09% of the isolates had MDR, prevalent and distributed in different clades, with a relatively high rate and low pathogenicity. There was no difference in MDR between the diarrheal (49/70) and healthy groups (15/24). Conclusion: We developed a random forest (RF) prediction model of TEM.1 + baeR + mphA + mphB + QnrS1 + AAC.3-IId to identify MDR status, highlighting its potential for early resistance identification. The causes of MDR are likely mobile units transmitting the ARGs. In the future, we will continue to strengthen the monitoring of ARGs and MDR, and increase the number of strains to further verify the accuracy of the MDR markers.