Genotyping Characteristics of Human Fecal Escherichia coli and Their Association with Multidrug Resistance in Miyun District, Beijing.

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.

Identification of metabolites of pulsatilla saponin B7 in rats and in vitro by UHPLC-Q-TOF-MS / 中国药学杂志

OBJECTIVE: To identify the metabolites oi Pulsatilla oleanolic acid 3-α-L-rhamnopyranosyl (1→2) [β-D-glucopyr-anosyl-(1→4)]-α-L-pyran arabinoside (B7) in rat plasma, bile, urine, feces, and in vitro liver microsomes incubation system. METHODS: An ultra-high performance liquid chromatography combined with electrospray ionization quadrupole time of flight mass spectrometry (UHPLC-Q-TOF-MS) method was developed and successfully applied to the study on the metabolites of B7 in rat plasma, bile, urine, feces, and in vitro liver microsomes incubation system after oral administration. RESULTS: A total of 23 metabolites were identified, of which 12 metabolites were present in rat liver microsomes incubation system. CONCLUSION: Deglycosylation, demethylation glucuronidation, and hydroxylation are the major metabolic transformation forms of B7 in rats in vivo and in vitro.

Phenolic glycosides from Glycosmis pentaphylla.

Three new phenolic glycosides, named as glycopentosides A-C (1-3), along with nine known compounds were isolated from the n-BuOH extract of stems of Glycosmis pentaphylla. Their structures were determined by using spectroscopic and chemical methods. Bioassay showed that compound 10 (tachioside) could inhibit nitric oxide production in lipopolysaccharides-stimulated RAW 264.7 cells with IC50 value of 12.14 µM.