Genistin Represses the Proliferation and Angiogenesis While Accelerating the Apoptosis of Glioma Cells by Modulating the FOXC1-Mediated Wnt Signaling Pathway.

BACKGROUND: Glioma is a tumor originating from glial cells and is the most common primary brain tumor. At present, the main treatment methods for glioma include surgical resection and radiotherapy and chemotherapy, but the treatment effect is not very ideal. Genistin (GS) inhibits breast cancer cell growth while promoting apoptosis, but its effect and detailed molecular mechanism on glioma are yet to be defined. In addition, forkhead box C1 (FOXC1) has been found to be involved in the growth, invasion, and angiogenesis processes of glioma cells. METHODS: Human glioma cells in the Control, GS-6.25, GS-12.5, and GS25 (GS) groups were treated with 0, 6.25, 12.5, and 25 µM of Genistin, respectively, for 72 hours, and cells in the GS + NC (negative control) and GS + FOXC1 groups were transfected with negative control or forkhead box C1 (FOXC1) overexpression plasmids, respectively, prior to Genistin (25 µM) treatment for 72 hours. Next, the viability, proliferation, apoptosis, and angiogenesis of treated glioma cells were detected using Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'deoxyuridine (EdU) proliferation, flow cytometry, and tube formation assays. Meanwhile, the half-maximal inhibitory concentration (IC50) of Genistin in the treated glioma cells was calculated. Afterwards, quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot quantified the levels of FOXC1, Wnt1, Wnt3a, glycogen synthase kinase-3ß (GSK3ß), and phosphorylated GSK3ß (p-GSK3ß). RESULTS: Genistin inhibited viability, proliferation, and angiogenesis while promoting the apoptosis of glioma cells (p < 0.05, p < 0.001). Also, Genistin decreased the levels of FOXC1, Wnt1, and Wnt3a while increasing p-GSK3ß levels in glioma cells (p < 0.05, p < 0.01, p < 0.001). FOXC1 was up-regulated in glioma cells and tissues, and overexpressed FOXC1 overturned the effects of Genistin on the abovementioned factors in glioma cells (p < 0.05, p < 0.001). CONCLUSIONS: Genistin inhibits viability, proliferation, and angiogenesis while accelerating glioma cell apoptosis by modulating the FOXC1-mediated Wnt signaling pathway.

Lactobacillus salivarius CPU-01 Ameliorates Temozolomide-Induced Intestinal Mucositis by Modulating Gut Microbiota, Maintaining Intestinal Barrier, and Blocking Pro-inflammatory Cytokines.

Chemotherapy-induced intestinal mucositis is one of the major toxic side effects in the treatment of cancer patients. The purpose of this study is to screen lactic acid bacteria which could alleviate intestinal inflammation and damage induced by chemotherapeutic agents and explore the possible underlying mechanisms. Lactobacillus salivarius CPU-01 was selected from traditional Chinese fermented foods due to its protective effects on the toxicity of temozolomide in Caenorhabditis elegans. Eighteen ICR mice were randomly divided into 3 groups including control group, temozolomide-induced intestinal mucositis group, and temozolomide + L. salivarius CPU-01 group, and were used to investigate the effect of L. salivarius CPU-01 on chemotherapy-induced intestinal mucositis. It has been demonstrated that the administration of L. salivarius CPU-01 can prevent colon shortening and alleviate colon tissue damage caused by temozolomide-induced intestinal mucositis in mice. L. salivarius CPU-01 relieved the intestinal microbiota disorders caused by temozolomide and contributed to the growth of beneficial bacteria, such as Lactobacillus, Clostridia UCG - 014_norank, and Akkermansia. In vivo experiments also indicated that L. salivarius CPU-01 can suppress the level of temozolomide-induced pro-inflammatory cytokines in serum and mRNA expression in the small intestine tissues. It was also found that L. salivarius CPU-01 significantly increased the expressions of intestinal tight junction (TJ) proteins, ZO-1, and Occludin proteins in mice treated with temozolomide. These findings suggest that L. salivarius CPU-01 can ameliorate temozolomide-induced intestinal mucositis by modulating gut microbiota, blocking pro-inflammatory cytokines, and repairing the intestinal barrier. These findings suggest probiotics may serve as a potential alternative therapeutic strategy for the prevention of chemotherapy-induced intestinal mucositis in the future.

ß-sitosterol inhibits trimethylamine production by regulating the gut microbiota and attenuates atherosclerosis in ApoE-/- mice.

The intestinal microbial metabolite trimethylamine (TMA), which is activated by flavin monooxygenase (FMO) to produce trimethylamine-N-oxide (TMAO), has been implicated in the pathogenesis of atherosclerosis (AS), leading to the development of therapeutic strategies for AS. This study aimed to investigate whether ß-sitosterol can inhibit TMA production in ApoE-/- mice by reshaping the gut microbial structure. 16S rRNA sequencing of the gut microbiota showed that ß-sitosterol has beneficial effects on intestinal flora function, especially the inhibition of bacteria genera that contain the gene cholintrimethylamine lyase, which is responsible for the major pathway for TMA production. In parallel, ß-sitosterol effectively reduced the TMA, FMO3, and TMAO levels while ameliorating the atherosclerotic plaques of AS mice. Moreover, ß-sitosterol could alleviate cholesterol metabolism and the inflammatory response, and improve the antioxidant defense capacity. These studies offer new insights into the mechanisms responsible for the antiatherosclerotic effects of ß-sitosterol, which targets the microbiota-metabolism-immunity axis as a possible therapy for AS.

Gut Microbiota and Inflammatory Cytokine Changes in Patients with Ankylosing Spondylitis.

Ankylosing spondylitis (AS) is a chronic inflammatory disease characterized by sacroiliac joint lesions and spinal ascending involvement. The aim of this work was at investigating the gut microbiota profile and proinflammatory cytokines in AS patients. Gut microbiota of AS patients was clearly different from that of healthy human controls. 16S rRNA sequencing analysis demonstrated a changed microbial diversity in the AS patients, and there was a significant increase in the abundance of Cyanobacteria, Deinococcota, Patescibacteria, Actinobacteriota, and Synergistota at a phyla level increased in AS, while the relative abundance of Acidobacteriota, Bdellovibrionota, Campylobacterota, Chloroflexi, Gemmatimonadota, Myxococcota, Nitrospirota, Proteobacteria, and Verrucomicrobiota declined in AS patients. ELISA results for the markers of inflammation in the AS patients revealed increased concentrations of proinflammatory cytokines such as IL-23, IL-17, and IFN-γ. Our findings support the fact that the intestinal microbiota are altered in AS with an inflammatory status, which indicates that gut microbiota should be a potential target for ankylosing spondylitis therapy.

Downregulation of microRNA-185 expression in diabetic patients increases the expression of NOS2 and results in vascular injury.

The aim of the present study was to investigate the regulatory effect and mechanism of microRNA (miR)-185 in diabetic angiopathy. The expression of miR-185 and nitric oxide synthase 2 (NOS2) in the blood from diabetic patients was examined by reverse transcription-quantitative PCR and enzyme-linked immunosorbent assay. After establishment of diabetic rats, the expression of miR-185 and NOS2 in vascular tissues and blood was also measured. Then, miR-185 was overexpressed in HMEC-1 cells and the expression of NOS2 was determined. Dual-luciferase reporter assay was used to identify the direct interaction between miR-185 and NOS2 mRNA. The expression of NOS2 was upregulated and the expression of miR-185 was downregulated in the blood from patients with diabetes. Vascular tissues and blood of diabetic rats showed similar trends compared with that of human. HMEC-1 cells with overexpression of miR-185 had decreased expression of NOS2. Dual-luciferase reporter assay demonstrated the direct binding between miR-185 and NOS2. The present study demonstrates that upregulation of NOS2 in diabetic patients is associated with the downregulation of miR-185, which participates in the progression of diabetes possibly through regulating NOS2 expression.

Toxicity of Melastoma dodecandrum Lour. and its effects on lipopolysaccharide-induced inflammation and oxidative stress.

Melastoma dodecandrum Lour. (MDL) is component used in traditional Chinese medicine that is widely distributed throughout southern China. MDL has been long utilized in clinical treatment for various conditions, such as inflammation. However, the toxicity and underlying anti-inflammatory mechanism of MDL remain to be elucidated. In the present study, Sprague-Dawley rats received intragastric administration of MDL for 2 months, and the toxicity of MDL was investigated. The rats were treated with lipopolysaccharide (LPS) for 8 h to determine the potential anti-inflammatory mechanism of MDL. The results demonstrated that MDL alone did not affect the expression levels of factors associated with inflammation (IL-1ß, IL-6 and TNF-α) and oxidative stress [malondialdehyde (MDA), superoxide dismutase (SOD) and nitric oxide (NO)] in the rat serum and exerted no effects on rat liver and kidneys. By contrast, MDL attenuated LPS-induced inflammation and oxidative stress by regulating specific cytokines, such as IL-1ß, IL-6, TNF-α, MDA, SOD and NO in the rat serum and alleviated LPS-induced liver and kidney damage. Additionally, compared with the LPS group, MDL inhibited CD4+ T cell differentiation into Th1 and Th17 cells and enhanced CD4+ T cell differentiation into Th2 and Treg cells. MDL also suppressed reactive oxygen species (ROS) production and mitochondrial apoptosis by modulating mitochondrial apoptosis-related proteins in spleen CD4+ T cells. In conclusion, the results of the present study demonstrated the non-toxic nature of MDL and revealed that it alleviated LPS-induced inflammation and oxidative stress by regulating differentiation and ROS production in CD4+ T cells.

EVA1B to Evaluate the Tumor Immune Microenvironment and Clinical Prognosis in Glioma.

Background: Previous research indicated that the tumor cells and microenvironment interactions are critical for the immunotherapeutic response. However, predicting the clinical response to immunotherapy remains a dilemma for clinicians. Hence, this study aimed to investigate the associations between EVA1B expression and prognosis and tumor-infiltrating immune cells in glioma. Methods: Firstly, we detected the EVA1B expression in glioma tissues through biological databases. The chi-squared test, Kaplan-Meier, and univariate and multivariate Cox regression analyses were used to analyze the clinical significance of EVA1B expression. The correlation between EVA1B expression and levels of tumor-infiltrating immune cells in glioma tissues was investigated. Receiver operating characteristic (ROC) analysis was performed to compare the predictive power between EVA1B and other commonly immune-related markers. Results: In the CGGA cohort of 325 glioma patients, we found that EVA1B was upregulated in glioma, and increased with tumor grade. High EVA1B expression was prominently associated with unfavorable clinicopathological features, and poorer survival of patients, which were further confirmed by TCGA (n=609) and GEO (n=74) cohorts. Furthermore, multivariate analysis indicated that EVA1B is an independent prognostic biomarker for glioma. Importantly, EVA1B overexpression was associated with a higher infiltration level of CD4+ T cells, CD8+ T cells, B cells, macrophages, and neutrophils in glioma. ROC curves showed that, compared with PD-L1, CTLA-4, and Siglec15, EVA1B presented a higher area under the curve (AUC) value (AUC=0.824) for predicting high immune infiltration levels in glioma. Conclusions: We found that EVA1B was upregulated and could act as a poor prognostic biomarker in glioma. Importantly, EVA1B overexpression was associated with the immune infiltration levels of immune cells including B cells, CD4+ T cells, CD8+ T cells, macrophages, and neutrophils, and strongly with the overall immune infiltration levels of glioma. These findings suggested that EVA1B might be a potential biomarker for evaluating prognosis and immune infiltration in glioma.

The Role of miR-34c-5p in Osteogenic Differentiation of Bone Marrow Mesenchymal Stem Cells.

BACKGROUND AND OBJECTIVES: Osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) plays a critical role in the success of lumbar spinal fusion with autogenous bone graft. This study aims to explore the role and specific mechanism of miR-34c-5p in osteogenic differentiation of BMSCs. METHODS AND RESULTS: Rabbit model of lumbar fusion was established by surgery. The osteogenic differentiation dataset of mesenchymal stem cells was obtained from the Gene Expression Omnibus (GEO) database, and differentially expressed miRNAs were analyzed using R language (limma package). The expressions of miR-34c-5p, miR-199a-5p, miR-324-5p, miR-361-5p, RUNX2, OCN and Bcl-2 were determined by qRT-PCR and Western blot. ELISA, Alizarin red staining and CCK-8 were used to detect the ALP content, calcium deposition and proliferation of BMSCs. The targeted binding sites between miR-34c-5p and Bcl-2 were predicted by the Target database and verified using dual-luciferase reporter assay. MiR-34c-5p expression was higher in rabbit lumbar fusion model and differentiated BMSCs than normal rabbit or BMSCs. The content of ALP and the deposition of calcium increased with the osteogenic differentiation of BMSCs. Upregulation of miR-34c-5p reduced cell proliferation and promoted ALP content, calcium deposition, RUNX2 and OCN expression compared with the control group. The effects of miR-34c-5p inhibitor were the opposite. In addition, miR-34c-5p negatively correlated with Bcl-2. Upregulation of Bcl-2 reversed the effects of miR-34c-5p on ALP content, calcium deposition, and the expressions of RUNX2 and OCN. CONCLUSIONS: miR-34c-5p could promote osteogenic differentiation and suppress proliferation of BMSCs by inhibiting Bcl-2.

Upregulation of hsa-miR-196a-5p is associated with MIR196A2 methylation and affects the malignant biological behaviors of glioma.

Hsa-miR-196a-5p is involved in tumorigenesis and progression. However, the driving factors for hsa-miR-196a-5p overexpression and its correlation with the clinicopathological features and prognosis of patients remain unclear in glioma. Thus, this study aimed to investigate the prognostic value of hsa-miR-196a-5p and its correlation with MIR196A2 methylation in glioma. We observed that hsa-miR-196a-5p expression was upregulated in glioma. Next, 112 patients were divided into high (n = 56) and low (n = 56) hsa-miR-196a-5p expression groups. The chi-square test showed that hsa-miR-196a-5p expression was significantly related to age, WHO grade, histopathology, IDH mutation status, and 1p/19q codeletion. Univariate and multivariate Cox regression analyses showed that hsa-miR-196a-5p expression was an independent prognostic factor. GO and KEGG enrichment analyses showed that hsa-miR-196a-5p may be involved in the MAPK signaling, focal adhesion and cancer-related pathways. Compared with the normal astrocyte cell line, glioma cell lines had an unregulated MIR196A2 methylation level, which was confirmed by TCGA data. The hypermethylated CpG sites of MIR196A2 were mainly concentrated in the gene body region, which was significantly associated with hsa-miR-196a-5p overexpression. Kaplan-Meier curves revealed that MIR196A2 hypermethylation was a poor prognostic factor. These findings suggest that hsa-miR-196a-5p overexpression may be involved in malignant biological behaviors, and MIR196A2 hypermethylation of the gene body was significantly associated with hsa-miR-196a-5p overexpression, which was a poor prognostic factor of glioma. Therefore, MIR196A2 hypermethylation may act as an early marker of prognosis of patients with glioma.

N6-methyladenine-related genes affect biological behavior and the prognosis of glioma.

BACKGROUND: Although aberrant expression of N6-methyladenine (m6 A) methylation-related genes contribute to tumorigenesis in many solid tumors, the prognostic value of the m6 A-related genes and their correlation with clinicopathological features in gliomas need advanced study. METHODS: The clinical and sequencing data of 288 patients with glioma were extracted from Chinese Glioma Genome Atlas database. By univariate and multivariable Cox regression analysis, the m6 A-related prognostic genes were identified, and their correlation with clinicopathological features was further analysis. A nomogram was constructed by R software and the performance of it was assessed by calibration and time-dependent receiver operating characteristic curve. RESULTS: Nine m6 A-related genes were identified as independent prognostic factors, which were mostly enriched in RNA splicing, regulation of immune response and vesicle-mediated transport. By expression value and regression coefficient of these genes, we constructed risk score of each patient, which was highly associated with clinicopathological features. Kaplan-Meier curve showed that the prognosis of patients with high-risk scores was significantly worse than that with low-risk scores (HR = 4.30, 95% CI = 3.16-5.85, p < 0.0001). A nomogram was constructed based on the nine m6 A-related genes signature and clinicopathological features with well-fitted calibration curves (c-index = 0.82), showing high specificity and sensitivity (area under the curve for 1-, 3-, and 5-years survival probability = 0.874, 0.918, and 0.934). CONCLUSIONS: A nine m6 A-related genes signature was identified in gliomas. The m6 A-related risk score is a novel prognostic factor for patients with glioma, and is associated with clinicopathological features. Moreover, the nomogram based on the nine m6 A-related genes signature and clinicopathological features had good efficacy in predicting the survival probability.

Screening of autophagy genes as prognostic indicators for glioma patients.

Although autophagy is reported to be involved in tumorigenesis and cancer progression, its correlation with the prognosis of glioma patients remains unclear. Thus, the aim of this study was to identify prognostic autophagy-related genes, analyze their correlation with clinicopathological features of glioma, and further construct a prognostic model for glioma patients. After 139 autophagy-related genes were obtained from the GeneCards database, their expression data in glioma patients were extracted from the Chinese Glioma Genome Atlas database. Univariate and multivariate COX regression analyses were performed to identify prognostic autophagy-related genes. Ten hub autophagy-related genes associated with prognosis were identified. The autophagy risk score (ARS) was only positively correlated with histopathology (P = 0.000) and World Health Organization grade (P = 0.000). Kaplan-Meier analysis showed that the overall survival of patients with a high ARS was significantly worse than that of patients with a low ARS (hazard ratio = 1.59, 95% confidence interval = 1.25-2.03, P = 0.0001). In addition, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses revealed several common biological processes and signaling pathways related to the 10 hub genes in glioblastoma. A prediction model was developed for glioma patients, which demonstrated high prediction efficiency on calibration. Moreover, the area under the receiver operating characteristic curve values for 1-, 3- and 5-year survival probabilities were 0.790, 0.861, and 0.853, respectively. In conclusion, we identified 10 autophagy-related genes that can serve as novel prognostic biomarkers for glioma patients. Our prediction model accurately predicted patient outcomes, and thus, may be a valuable tool in clinical practice.

The effect of Bailemian on neurotransmitters and gut microbiota in p-chlorophenylalanine induced insomnia mice.

Bailemian (BLM) is reportedly used for the treatment of insomnia as a traditional Chinese medicine in China for many years. However, the anti-insomnia mechanisms of BLM are still unknown. The present study aims to investigate the anti-insomnia activity of BLM by evaluating its influence on the relevant neurotransmitters and gut microbiota in p-chlorophenylalanine (PCPA) induced insomnia mice. The results indicated that the level of GABA, 5-HT, DA, and NE is significantly decreased in the PCPA-induced insomnia model group compared with the control group, while the level of Glu is higher than the control group. Treatment with BLM could ameliorate the symptoms of insomnia and significantly modulate the levels of the neurotransmitters mentioned above in brain and colonic faeces. Furthermore, the structure and composition of gut microbiota were changed after the administration of BLM and can increase the percentage of beneficial bacterial species in gut microbiota. These results indicated that Bailemian could ameliorate the symptoms of insomnia, and its effects may be through modification of the neurotransmitters levels and gut microbiota composition.

Liuwei Dihuang exhibits antidiabetic effects through inhibiting α-amylase and α-glucosidase.

OBJECTIVE: Liuwei Dihuang (LWDH) is a famous traditional herbal medicine formula in China that may regulate the balance of kidney yin yang and has been used to restore functional insufficiency of the kidney for a long time in China. METHODS: In this study, the water extract of LWDH was tested for its α-Amylase and α-Glucosidase inhibitory activities, and its anti-diabetic property in streptozotocin (STZ)-induced diabetic mice was also analyzed. RESULTS: LWDH extract inhibited α-Glucosidase and α-Amylase activities in a dose- dependent manner. Treatment of streptozotocin-induced diabetic mice with LWDH extract decreased camp, fasting blood glucose, TC, TG, LDL-c, HbA1C, Urine volume levels and Urine sugar, increased HDL-c level when compared to STZ induced diabetic mice. CONCLUSION: This study demonstrates that extract of LWDH can inhibit α-amylase and α-glucosidase activities and shows anti-diabetic effect in a mice preclinical model.

Evaluation of the antibacterial activity of a cationic polymer in aqueous solution with a convenient electrochemical method.

Quaternized chitosan is a cationic biopolymer with good antibacterial activity, biocompatibility, and biodegradability, and it has been widely applied in many fields. We have developed a convenient method to evaluate the antibacterial activity of hydroxypropyltrimethylammonium chloride chitosan (HACC) with a nonionic surfactant poloxamer in aqueous solution by monitoring the change of the oxidation peak current in cyclic voltammetry. Increasing values of the oxidation peak current were positively correlated with the antibacterial activity of HACC-poloxamer solutions. Optical microscope images, the zeta potential, and fluorescence spectroscopy showed that the aggregation state of HACC-poloxamer was related to the ratio of the two polymers and also to the antibacterial activity and oxidation peak current. At an HACC-to-poloxamer ratio of 1:0.75, the maximum surface charge density and the smooth edge of HACC-poloxamer aggregates can accelerate diffusion in aqueous solution. It is expected that this convenient method can be applied for a quick evaluation of the antibacterial activity of cationic biopolymers in aqueous solution. Graphical Abstract The cyclic voltammograms of MB in HACC/poloxamer solution, and the antibacterial efficiency against S. aureus after incubated with HACC (a) and 1/0.75 of HACC/poloxamer (b).

Tea polyphenols as an antivirulence compound Disrupt Quorum-Sensing Regulated Pathogenicity of Pseudomonas aeruginosa.

Green tea, a water extract of non-fermented leaves of Camellia sinensis L., is one of the nonalcoholic beverages in China. It is becoming increasingly popular worldwide, because of its refreshing, mild stimulant and medicinal properties. Here we examined the quorum sensing inhibitory potentials of tea polyphenols (TP) as antivirulence compounds both in vitro and in vivo. Biosensor assay data suggested minimum inhibitory concentrations (MICs) of TP against selected pathogens were 6.25 ~ 12.5 mg/mL. At sub-MIC, TP can specifically inhibit the production of violacein in Chromobacterium violaceum 12472 with almost 98% reduction at 3.125 mg/mL without affecting its growth rate. Moreover, TP exhibited inhibitory effects on virulence phenotypes regulated by QS in Pseudomonas aeruginosa. The total proteolytic activity, elastase, swarming motility and biofilm formation were reduced in a concentration-dependent manner. In vivo, TP treatment resulted in the reduction of P. aeruginosa pathogenicity in Caenorhabditis elegans. When its concentration was 3.125 mg/mL, the survival rate reached 63.3%. In the excision wound infection model, the wound contraction percentage in treatment groups was relatively increased and the colony-forming units (CFU) in the wound area were significantly decreased. These results suggested that TP could be developed as a novel non-antibiotic QS inhibitor without killing the bacteria but as an antivirulence compound to control bacterial infection.

Characterization of N-Acyl-homoserine Lactones (AHLs)-Deficient Clinical Isolates of Pseudomonas aeruginosa.

Pseudomonas aeruginosa is an opportunistic pathogen causing severe respiratory infections. Acylated homoserine lactones (AHLs) are self-generated diffusible signal molecules that mediate population density dependent gene expression (quorum sensing, QS) in a variety of Gram-negative bacteria, and several virulence genes of bacterial pathogens are known to be controlled by QS. Hence, fitness mutant of virulent factors is beneficial for natural selection. In this study, strains of P. aeruginosa isolated from chronic lung infection of cystic fibrosis patients, were screened for AHLs production by using indicator strains of Chromobacterium violaceum CV026 and Agrobacterium tumefaciens strain At136. Four AHLs defective strains were selected from fifty-three clinical isolates. PCR analysis revealed that only one isolate was negative for lasR gene. These four AHLs defective isolates produced less virulence factors and forming less biofilm than PAO1. Only isolate PA41 produce little more pyocyanin than PAO1. The results indicate that, despite the pivotal role of QS in the pathogenesis of P. aeruginosa infections, AHLs-deficient strains are still capable of causing infections in human.

Azithromycin Reduces the Production of α-hemolysin and Biofilm Formation in Staphylococcus aureus.

Staphylococcus aureus causes a broad range of life-threatening diseases in humans. This bacterium produces a large number of extracellular virulence factors that are closely associated with specific diseases which are controlled by quorum sensing. In this study, we show that azithromycin was active against methicillin-resistant Staphylococcus aureus (MRSA) strains with MICs ranged from 32 to 64 µg/mL. Azithromycin at subinhibitory concentration, markedly reduced the production of α-hemolysin at (1/16MIC, 1/8MIC) and biofilm formation at (1/16MIC, 1/8MIC), respectively. The results indicated that sub-inhibitory concentrations of azithromycin decreased the production of α-hemolysin and biofilm formation in MRSA in a dose-dependent manner. Therefore, azithromycin may be useful in the treatment of α-hemolysin producing and biofilm formation MRSA infections.

Antibiotic resistance profiles and quorum sensing-dependent virulence factors in clinical isolates of pseudomonas aeruginosa.

Pseudomonas aeruginosa produces multiple virulence factors that have been associated with quorum sensing. The aim of this study was to evaluate the prevalence of drug resistant profiles and quorum sensing related virulence factors. Pseudomonas aeruginosa were collected from different patients hospitalized in China, the isolates were tested for their susceptibility to different common antimicrobial drugs and detected QS-related virulence factors. We identified 170 isolates displaying impaired phenotypic activity, approximately 80 % of the isolates were found to exhibit the QS-dependent phenotypes, among them, 12 isolates were defective in AHLs production, and therefore considered QS-deficient strains. Resistance was most often observed to Cefazolin (81.2 %), followed by trimethoprim-sulfamethoxazole (73.5 %), ceftriaxone (62.4 %) and Cefotaxime, Levofloxacin, Ciprofloxacin (58.8 %), and to a lesser extent Meropenem (20.0 %), Cefepime (18.8 %), and Cefoperazone/sulbactam (2.4 %) The QS-deficient isolates that were negative for virulence factor production were generally less susceptible to the antimicrobials. The results showed a high incidences of antibiotic resistance and virulence properties in P. aeruginosa, and indicate that the clinical use of QS-inhibitory drugs that appear superior to conventional antimicrobials by not exerting any selective pressure on resistant strains.