Antibiotic resistance and epidemiological characteristics of polymyxin-resistant Klebsiella pneumoniae. / è€å¤šé»èŒç´ è‚ºç‚Žå ‹é›·ä¼¯èŒçš„è¯æ•ç‰¹å¾åŠæµè¡Œç— å­¦ç‰¹ç‚¹.

OBJECTIVES: The emergence of polymyxin-resistant Klebsiella pneumoniae (KPN) in clinical settings necessitates an analysis of its antibiotic resistance characteristics, epidemiological features, and risk factors for its development. This study aims to provide insights for the prevention and control of polymyxin-resistant KPN infections. METHODS: Thirty clinical isolates of polymyxin-resistant KPN were collected from the Third Xiangya Hospital of Central South University. Their antibiotic resistance profiles were analyzed. The presence of carbapenemase KPC, OXA-48, VIM, IMP, and NDM was detected using colloidal gold immunochromatography. Hypervirulent KPN was initially screened using the string test. Biofilm formation capacity was assessed using crystal violet staining. Combination drug susceptibility tests (polymyxin B with meropenem, tigecycline, cefoperazone/sulbactam) were conducted using the checkerboard method. Polymyxin-related resistance genes were detected by PCR. Multi-locus sequence typing (MLST) was performed for genotyping and phylogenetic tree construction. The study also involved collecting data from carbapenem-resistant (CR)-KPN polymyxin-resistant strains (23 strains, experimental group) and CR-KPN polymyxin-sensitive strains (57 strains, control group) to analyze potential risk factors for polymyxin-resistant KPN infection through univariate analysis and multivariate Logistic regression. The induction of resistance by continuous exposure to polymyxin B and colistin E was also tested. RESULTS: Among the 30 polymyxin-resistant KPN isolates, 28 were CR-KPN, all producing KPC enzyme. Four isolates were positive in the string test. Most isolates showed strong biofilm formation capabilities. Combination therapy showed additive or synergistic effects. All isolates carried the pmrA and phoP genes, while no mcr-1 or mcr-2 genes were detected. MLST results indicated that ST11 was the predominant type. The phylogenetic tree suggested that polymyxin-resistant KPN had not caused a hospital outbreak in the institution. The use of two or more different classes of antibiotics and the use of polymyxin were identified as independent risk factors for the development of polymyxin-resistant strains. Continuous use of polymyxin induced drug resistance. CONCLUSIONS: Polymyxin-resistant KPN is resistant to nearly all commonly used antibiotics, making polymyxin-based combination therapy a viable option. No plasmid-mediated polymyxin-resistant KPN has been isolated in the hospital. Polymyxin can induce resistance in KPN, highlighting the need for rational antibiotic use in clinical settings to delay the emergence of resistance.

High-sugar high-fat treatment induces autophagy of retinal microvascular endothelial cells.

OBJECTIVE: To investigate the role of high-sugar high-fat treatment in inducing autophagy of rat retinal microvascular endothelial cells. METHODS: The optimal concentrations and time points of glucose and oxidized low-density lipoprotein (ox-LDL) in inducing rat retinal microvascular endothelial cells were determined by examining the proliferate rate by CCK-8 assay. They were divided into control group (blank control), model group (treatment of 50 mM glucose and 10 µg/ml ox-LDL for 24 h), chloroquine group (treatment of 20 µM chloroquine, 50 mM glucose and 10 µg/ml ox-LDL for 24 h), resveratrol group (treatment of 50 µM resveratrol, 50 mM glucose and 10 µg/ml ox-LDL for 24 h) and MITO-Tempol group (treatment of 20 µM MITO-Tempol, 50 mM glucose and 10 µg/ml ox-LDL for 24 h). Reactive oxygen species (ROS) level in rat retinal microvascular endothelial cells induced with high sugar high-fat treatment was measured by flow cytometry. In addition, protein levels of cathepsin B and cathepsin D in rat retinal microvascular endothelial cells induced with high sugar high-fat treatment were examined by immunofluorescence, and protein levels of LC3 A/B and the autophagy substrate P62 were detected by Western blot. RESULTS: Primary retinal microvascular endothelial cells were isolated from neonatal Sprague-Dawley (SD) rats. ROS level was significantly higher in model group than that of control group (P < 0.05). Compared with that of model group, ROS level was significantly reduced in chloroquine group and MITO-Tempol group, which was significantly elevated in resveratrol group (P < 0.05). Positive expressions of cathepsin B and cathepsin D were significantly reduced in model group than those of control group (P < 0.05). They were significantly elevated in chloroquine group and MITO-Tempol group, and reduced in resveratrol group than those of model group (P < 0.05). LC3 A/B and P62 were significantly upregulated in model group than those of control group (P < 0.05). Compared with those of model group, LC3 A/B and P62 were significantly downregulated in chloroquine group and MITO-Tempol group, and upregulated in resveratrol group (P < 0.05). CONCLUSION: High-sugar high-fat treatment induces autophagy of rat retinal microvascular endothelial cells, which can be intervened to a certain extent by chloroquine and MITO-Tempol.

[Transcutaneous Electrostimulation of Auricular Otopoints Reduces Epileptic Attack Possibly by Suppressing Hippocampal Gliocyte Proliferation and Regulating IL-6 and IL-10 Expression in Chronic Temporal Lobe Epilepsy Rats].

OBJECTIVE: To observe the effect of transcutaneous otopoint electrostimulaiton (TCOES) on seizure frequency, immunoreactivity of hippocampal gliocytes and expression of proinflammatory cytokine interleukin-6(IL-6) and anti-inflammatory cytokine IL-10 in chronic temporal lobe epilepsy (CTLE) rats, so as to investigate its antiepileptic mechanism. METHODS: Thirty-six SD rats were randomly divided into control, model and TCOES groups (n=12 in each group). The CTLE model was established by intraperitoneal injection (i.p.i.) of lithium chloride (127.2 mg/kg), scopolamine (1 mg/kg, 20 h after the 1st injection) and pilocarpine (10 mg/kg, 30 min after scopolamine injection). Rats of the control group were treated by i.p.i. of normal saline. TCOES (1 mA, 20 Hz) was applied to bilateral otopoint "Heart"-"Lung"-"Subcortex" region for 20 min, once daily for 6 weeks. The epileptic attack was observed by a video monitoring system. The numbers of ionized calcium-binding adapter molecule-1 (Iba 1)-labeled microgliacytes and glial fibrillary acidic protein (GFAP)-labeled astrocytes in the CA 1 and CA 3 regions of hippocampus were counted under light microscope after immunostaining, and the expression levels of hippocampal IL-6 and IL-10 proteins and genes were determined by immunofluorescence and quantitative real-time PCR, respectively. RESULTS: After TCOES intervention, the seizure frequency was significantly decreased in comparison with pre-treatment(P<0.05), modeling-induced dramatic increase of the numbers of microgliacytes and astrocytes,IL-6 immunoactivity in the hippocampal CA 1 and CA 3 regions, and IL-6 mRNA expression in the hippocampus were significantly suppressed (P<0.05), and hippo-campal IL-10 immunoactivity and mRNA expression were considerably up-regulated in comparison with the model group (P<0.05). CONCLUSIONS: TCOES intervention has an antiepileptic effect in CTLE rats, which may be associated with its effects in suppressing gliocyte proliferation, suppressing the expression of proinflammatory cytokine IL-6, and up-regulaiting the expression of anti-inflammatory cytokine IL-10 in the hippocampus.

[Therapeutic effect of acupuncture on female's climacteric depression and its effects on DA, NE and 5-HIAA contents].

OBJECTIVE: To observe therapeutic effects of acupuncture on female's climacteric depression and to study on the mechanism. Methods Sixty cases enrolled were randomly divided into an acupuncture group and a control group, 30 cases in each group. In the acupuncture group, acupuncture were given at Ganshu (BL 18), Shenshu (BL 23), Xinshu (BL 15), etc. with uniform reinforcing-reducing method, once each day, and the control group were treated with oral administration of fluexertine hydrochloride, 20 mg, once daily. HAMD scale was used for assessment before treatment and 2,4,6 weeks after treatment. Blood dopamine (DA), norepinephrine (NE) and 5-hydroxy-indoleacetic acid (5-HIAA) contents were detected before treatment and after one therapeutic course. Results The total effective rate was 86.7% in the acupuncture group and 92.9% in the control group with no significant difference between the two groups (P > 0.05). After treatment, DA content increased significantly in the acupuncture group with a significant difference as compared with that of the control group (P < 0.05); and after treatment NE and 5-HIAA contents in the two groups significantly increased as compared with that before treatment (P < 0.05, P < 0.01), with no significant difference between the two groups (P > 0.05). Conclusion Acupuncture can benignly and comprehensively regulate general functions, and increase contents of monoamines in the body, so as to play the role of anti-depression.