Objective: This study characterized the resistance phenotype and genotype of K. intermedia L-40-1, isolated from a pig in Jilin Province, China, and investigated the genomic determinants of its antibiotic resistance. Methods: 16S rRNA sequencing was performed to identify the strain. The resistance phenotype was assessed by determining minimum inhibitory concentrations (MICs), and resistance determinants were characterized by whole-genome sequencing. Comparative genomic analysis against the national center for biotechnology information (NCBI) database of K. intermedia strains was conducted to determine phylogenetic relationships and resistance gene profiles. Results: L-40-1 exhibited high resistance to β-lactams, cephalosporins, macrolides, aminoglycosides, and sulfonamides. Comparative analysis identified 19 high-frequency resistance genes (e.g., arnT, rsmA, emrR, and acrA). A 159,618 bp plasmid (PYL-8) harbored multiple resistance genes (e.g., sul1, dfrA27, qnrB6, and tet(D)) and transposons (e.g., IS6, IS1, and Tn3), contributing to its multidrug resistance. Chromosomal and plasmid-borne resistance mechanisms were identified. Conclusions and Relevance: K. intermedia L-40-1 uses a combination of chromosomal and plasmid-mediated resistance genes, facilitated by transposons, to confer multidrug resistance. This highlights the need for surveillance of K. intermedia in livestock to mitigate the spread of antibiotic resistance.

Objective To investigate the protective effect of sipunculusnudus polysaccharide (SNP) on HUVEC cell damage induced by ionizing radiation.Methods The survival rate of HUVEC cells was detected by CCK-8,after irradiation with 137Cs γ-rays and pre-treatment with SNP,and optimal absorption dose rate of 137Cs γ-ray was 8 Gy and optimal concentration of SNP was confirmed to be 100 g/mL.The radiation sensitivity of HUVEC cells pretreated with SNP was detected by clone formation assay.Apoptosis rate of HUVEC cells was measured by Hoechst33342/PI staining and flow cytometry.Results The results indicated that the survival rate of HUVEC cells decreased significantly with the increase of irradiation dose (P ＜ 0.01).When pretreated with SNP,the survival rate of HUVEC cells significantly increased,and it was positively correlated with the concentration of SNP.When the end concentration of SNP was as high as 100 μg/ml,the survival rate reached the highest (84.96％),and the survival rate after irradiation increased from 63.43％ to 84.96％ (P ＜0.01).The rate of clone formation in the SNP-treated group was also significantly higher as compared with that of the control group(P ＜ 0.01).Compared with the irradiation model group,the apoptosis rate and intracellular reactive oxygen species (ROS) levels in the SNP-treated group decreased significantly,with the apoptosis rate decreasing from 15.6％ to 6.8％,and ROS level decreasing from 47.10 × 104 to 41.77 × 104,with statistical signficance (P ＜ 0.05 or P ＜ 0.01).The blue fluorescence of the Hoechst 33342 coloring and red fluorescence of PI coloring also decreased signficantly in the SNP-treated group (P ＜ 0.01).Conclusion The results suggested that SNP pretreatment could increase cell survival rate and cloning rate after irradiation,reduce radiation-induced apoptosis and intracellular ROS levels effectively,indicating that SNP treatment could exert a certain protective effect on HUVEC cell damage induced by ionizing radiation.

Objective To investigate the protective effect of sipunculusnudus polysaccharide (SNP) on HUVEC cell damage induced by ionizing radiation.Methods The survival rate of HUVEC cells was detected by CCK-8,after irradiation with 137Cs γ-rays and pre-treatment with SNP,and optimal absorption dose rate of 137Cs γ-ray was 8 Gy and optimal concentration of SNP was confirmed to be 100 g/mL.The radiation sensitivity of HUVEC cells pretreated with SNP was detected by clone formation assay.Apoptosis rate of HUVEC cells was measured by Hoechst33342/PI staining and flow cytometry.Results The results indicated that the survival rate of HUVEC cells decreased significantly with the increase of irradiation dose (P ＜ 0.01).When pretreated with SNP,the survival rate of HUVEC cells significantly increased,and it was positively correlated with the concentration of SNP.When the end concentration of SNP was as high as 100 μg/ml,the survival rate reached the highest (84.96％),and the survival rate after irradiation increased from 63.43％ to 84.96％ (P ＜0.01).The rate of clone formation in the SNP-treated group was also significantly higher as compared with that of the control group(P ＜ 0.01).Compared with the irradiation model group,the apoptosis rate and intracellular reactive oxygen species (ROS) levels in the SNP-treated group decreased significantly,with the apoptosis rate decreasing from 15.6％ to 6.8％,and ROS level decreasing from 47.10 × 104 to 41.77 × 104,with statistical signficance (P ＜ 0.05 or P ＜ 0.01).The blue fluorescence of the Hoechst 33342 coloring and red fluorescence of PI coloring also decreased signficantly in the SNP-treated group (P ＜ 0.01).Conclusion The results suggested that SNP pretreatment could increase cell survival rate and cloning rate after irradiation,reduce radiation-induced apoptosis and intracellular ROS levels effectively,indicating that SNP treatment could exert a certain protective effect on HUVEC cell damage induced by ionizing radiation.

The significant changes in morphology and nitric oxide synthase (NOS) activity in cultured human aortic endothelial cells (HAEC) were observed when these cells were exposed to LPS, IL-1? and IFN-?. NOS activity increased at 6h of treatment, the time point that HAEC began to change and elongate. The cell shape became fibroblast like and the length to width ratio of the cells increased 2 times of that of the control at 20h treatment, the time point that NOS activity returned to control level.