Effect of chlorhexidine digluconate on antimicrobial activity,cell viability and physicochemical properties of three endodontic sealers

ObjectiveAssess the biological and physicochemical properties of AH Plus, BioRoot RCS and Pulp Canal Sealer (PCS) leachates with and without chlorhexidine (CHX).MethodsThe sealers were studied in no contact and 1-minute contact with CHX. For biological properties (antibacterial activity and cytotoxicity), leachates were formed in saline of freshly mixed, 1-, 7- and 28 days set sealers. The antibacterial properties of sealer leachates were investigated for planktonic and biofilm growth of E. faecalis, S. mutans, S.epidermidis and S.aureus. The 3-(4,5 dimethylthiazolyl-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to evaluate murine fibroblast cell viability after exposure to the leachates. The physical properties (water uptake, sorption, solubility, porosity, surface characteristics) of sealers and the pH of the immersion liquid (saline or distilled water) were also assessed over a 28-days period.ResultsCHX improved the antibacterial properties of the sealer leachates and reduced cell viability for all sealer leachates, except for freshly mixed PCS. BioRoot RCS leachates presented the highest antibacterial properties and cell viability with and without CHX contact. PCS was the material most affected by CHX in terms of physical properties, whereas for AH Plus, solubility was increased. CHX did not affect the physical properties of BioRoot RCS, except for solubility that was decreased. CHX contact did not change sealers’ alkalinity in distilled water whereas it increased it for AH Plus and BioRoot RCS in saline.SignificanceCHX improved the antibacterial efficacy of sealer leachates and either compromised or did not affect cell viability. CHX affected to various extent sealers’ physicochemical properties.     

Assessment of oral ciprofloxacin impaired gut barrier integrity on gut bacteria in mice

Gut bacteria and gut barrier plays important roles in body homeostasis. Ciprofloxacin (CPFX) is widely used to treat bacterial infections. However, whether high dosage of CPFX has side effects on gut barrier integrity is still unclear. Our results indicated that the High CPFX treatment (1 mg/ml) caused weight loss, nervousness, anorexia, and increased apoptosis cells in gut, but less influence was observed in the Low CPFX group (0.2 mg/ml). Meanwhile, the High CPFX treatment impaired tight junction molecules Ocln/ZO-1 level and down-regulated antibacterial genes expression (reg3γ, pla2g2α and defb1). Further, the High CPFX treatment increased pro-inflammatory cytokine IL-1β in intestinal tract, decreased IL-17A of duodenum but increased IL-17A of colon at day 37. In addition, the gut bacterial diversity and richness behaved significantly loss regarding CPFX treatment, especially in the High CPFX group during the experiment. Indole exhibited sharply decline in both Low and High CPFX groups at day 7, and the High CPFX mice needed longer time on restoring indole level. Meanwhile, CPFX treatment strongly decreased the concentrations of butyric acid and valeric acid at day 1. Correlation analysis indicated that the linked patterns between the key bacteria (families Bacteroidales_S247, Ruminococcaceae and Desulfovibrionaceae) and metabolites (indole and butyric acid) were disturbed via the CPFX treatment. In conclusion, the High CPFX treatment impaired the gut barrier with the evidence of reduced expression of tight junction proteins, increased apoptosis cells and inflammatory cells, decreased the bacterial diversity and composition, which suggesting a proper antibiotic-dosage use should be carefully considered in disease treatment.     

Antibiotic resistant bacteria and resistance genes in biofilms in clinical wastewater networks

Increasing isolation rates of resistant bacteria in the last years require identification of potential infection reservoirs in healthcare facilities. Especially the clinical wastewater network represents a potential source of antibiotic resistant bacteria. In this work, the siphons of the sanitary installations from 18 hospital rooms of two German hospitals were examined for antibiotic resistant bacteria and antibiotic residues including siphons of showers and washbasins and toilets in sanitary units of psychosomatic, haemato-oncological, and rehabilitation wards. In addition, in seven rooms of the haemato-oncological ward, the effect of 24 h of stagnation on the antibiotic concentrations and MDR (multi-drug-resistant) bacteria in biofilms was evaluated. Whereas no antibiotic residues were found in the psychosomatic ward, potential selective concentrations of piperacillin, meropenem and ciprofloxacin were detected at a rehabilitation ward and ciprofloxacin and trimethoprim were present at a haemato-oncology ward. Antibiotic resistant bacteria were isolated from the siphons of all wards, however in the psychosomatic ward, only one MDR strain with resistance to piperacillin, third generation cephalosporins and quinolones (3MRGN) was detected. In contrast, the other two wards yielded 11 carbapenemase producing MDR isolates and 15 3MRGN strains. The isolates from the haemato-oncological ward belonged mostly to two specific rare sequence types (ST) (P. aeruginosa ST823 and Enterobacter cloacae complex ST167). In conclusion, clinical wastewater systems represent a reservoir for multi-drug-resistant bacteria. Consequently, preventive and intervention measures should not start at the wastewater treatment in the treatment plant, but already in the immediate surroundings of the patient, in order to minimize the infection potential.     

PTPN6通过抑制SP1/p38 MAPK信号通路促进前列腺癌细胞的化疗敏感性

目的:研究PTPN6对前列腺癌细胞PC3的作用及其作用机制。方法:RT-PCR和Western blot实验检测前列腺癌组织和细胞以及癌旁组织和人前列腺上皮细胞中PTPN6的表达量；CCK-8和EDU染色实验检测PTPN6对前列腺癌细胞PC3增殖的影响；Western blot实验检测耐药相关蛋白P-gp和MRP-1的蛋白表达水平。结果:RT-PCR和Western blot结果显示，PTPN6在前列腺癌组织和细胞中的表达量显著低于癌旁组织和人前列腺上皮细胞中的表达量；过表达PTPN6显著抑制前列腺癌PC3细胞的增殖，并降低PC3细胞的耐药性；进一步的研究结果表明PTPN6可通过抑制SP1，并抑制p38 MAPK通路抑制PC3细胞的增殖和耐药。结论:PTPN6能够抑制前列腺癌细胞PC3的增殖和耐药，提高其化疗敏感性，作用机制是通过调控SP1/p38 MAPK信号通路来实现的，这一结果能够为临床上前列腺癌的诊断和治疗提供分子基础。     

Current status of countermeasures for infectious diseases and resistant microbes in the field of urology

A worldwide increase in antimicrobial‐resistant microbes due to the improper use of antimicrobial agents, along with a lack of progress in developing new antimicrobials, is becoming a societal problem. Although carbapenem‐resistant Enterobacteriaceae, which are resistant to carbapenem antimicrobials, first appeared in 1993, treatment options remain limited. Mechanisms behind antimicrobial resistance involve changes to microbial outer membranes, drug efflux pump abnormalities, β‐lactamase production and the creation of biofilms around cell bodies. Genetic information related to these forms of antimicrobial resistance exists on chromosomes and plasmids, and when located on the latter can easily be transmitted to other strains, no matter the species, which creates a risk of antimicrobial resistance spreading exceptionally rapidly. To prevent the spread of antimicrobial resistance, the World Health Organization in 2015 published an action plan on antimicrobial resistance, based on which World Health Organization member countries have laid out specific policies and targets. Urinary tract infections are a type of healthcare‐associated infection, and the sexually transmitted disease pathogen, Neisseria gonorrhoeae, has been included in a list of microbes that pose a risk to human health published by the US Centers for Disease Control and Prevention. Urologists face numerous problems when attempting to use antimicrobials properly, which is one method of dealing with antimicrobial resistance. Therefore, this article describes the current state of resistant microbes associated with urinary tract infections and countermeasures for antimicrobial resistance, including new antimicrobials.     

Effect of different modeling time on intestinal bacteria in letrozole induced PCOS rats

Objective: The differences of ovarian morphology, reproductive hormones, glucose and lipid metabolism and intestinal bacteria in rats with polycystic ovary syndrome (PCOS) induced by triazole were compared. Method: Eighteen 21 SPF female SD rats were randomly divided into group A (3-week group), group B (5-week group) and group D (control group) by random number table.Group A received letrozole + CMC-Na mixture by gavage in the first 3 weeks and CMC-Na solution by gavage in the last 2 weeks, group B received letrozole + CMC-Na mixture by gavage for 5 weeks, and group D received CMC-Na solution by gavage for 5 weeks, and all three groups of rats were fed with normal diet.At the end of gavage, the body weight of rats in each group was observed, the histological changes of ovaries were observed by hematoxylin-eosin (HE) staining, the serum levels of estradiol (E2), follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone (T), total cholesterol (TC), triglyceride (TG), fasting blood glucose (Glu), fasting insulin (FINS) and lipopolysaccharide (LPS) were measured by enzyme-linked immunosorbent assay (ELISA), and the LH/FSH ratio and insulin resistance index (HOMA IR) were calculated; the intestinal bacteria of rats were detected by 16S rRNA technique. Result: 1. Comparison of ovary histomorphology: Under light microscope, multiple luteum and oocytes were observed in mature follicles in group D, and granulosa cells were orderly arranged and multilayered, without cystic dilated follicles. There were no mature follicles in the ovarian tissues of group A and GROUP B. The follicles were irregular in structure and more cystic dilated follicles were visible. The number of granular cells in some follicles decreased or even disappeared. 2. Comparison of sex hormone levels: compared with group D, T level in group B was significantly increased (P < 0.001), and T level in group A had an upward trend (P > 0.05); The LH/FSH levels in group A and B were significantly increased (P < 0.001; P < 0.001). Compared with group A, E2 in group B was significantly decreased (P < 0.05) and T was significantly increased (P < 0.01). 3. Comparison of glucose and lipid metabolism levels: Compared with group D, TC levels in groups A and B were significantly increased (P < 0.01; P < 0.01). Compared with group A, TG in group B was significantly increased (P < 0.05). There were no significant differences in Glu, FINS and HOMA-IR levels among all groups. 4. Comparison of LPS levels: Compared with group D, the serum LPS levels of rats in groups A and B were significantly increased (P < 0.001; P < 0.01). 5. Intestinal flora analysis and comparison: At the phylum level, compared with group D, the abundance of Firmicutes in group B increased (P < 0.01), Firmicutes in group A showed an upward trend (P > 0.05), and the abundance of Bacteroidetes in groups A and B decreased (P < 0.05). At the genus level, compared with group D, Lactobacillus in group B increased (P < 0.01). The results of LEfSe analysis showed that there were differences in the composition of various intestinal bacteria among the three groups (LDA > 3).Conclusion: The phenotype of PCOS rats was related to the length of modeling, and the phenotypic characteristics of PCOS in rats at 5 weeks of modeling were more typical than those in rats at 3 weeks of modeling; PCOS can cause changes in intestinal flora, and the changes in the structure of intestinal flora between groups are related to different modeling duration.     

肠杆菌目细菌产耐碳青霉烯酶的基因分型检测方法进展

碳青霉烯类耐药肠杆菌科细菌（CRE）已成为全球性的公共卫生问题。有文献报道由CRE引起的感染，尤其是血流感染，会导致患者死亡率较高，为临床治疗带来了极大的挑战。肠杆菌科细菌耐碳青霉烯类药物的主要机制是细菌产生了不同型别的耐碳青霉烯类水解酶。目前只有少数几种新型抗菌药物可以用于CRE的治疗如头孢他啶/阿维巴坦，但头孢他啶/阿维巴坦对持有金属β内酰胺酶的CRE没有活性，所以快速、准确地检测CRE菌株所产碳青霉烯酶种类，对临床合理选择抗菌药物至关重要。本文就目前检测肠杆菌科细菌耐碳青霉烯类药物的基因分型实验方法的优缺点进行总结分析。     

Prospects for clinical applications of butyrate-producing bacteria

As the major source of energy for colonic mucosal cells and as an important regulator of gene expression, inflammation, differentiation, and apoptosis in host cells, microbiota-derived butyrate can enhance the intestinal mucosal immune barrier, modulate systemic immune response, and prevent infections. Maintaining a certain level of butyrate production in the gut can help balance intestinal microbiota, regulate host immune response, and promote the development and maintenance of the intestinal mucosal barrier. Butyrate-producing bacteria act as probiotics and play important roles in a variety of normal biological functions. Bacteriotherapeutic supplementation by using fecal microbiota transplantation to restore butyrate-producing commensal bacteria in the gut has been very successful in the treatment of recurrent and refractory Clostridium difficile (C. difficile) infection or C. difficile-negative nosocomial diarrhea. Administration of probiotics that include butyrate-producing bacteria may have a role in the treatment of inflammatory bowel diseases and in the prevention of necrotizing enterocolitis and late-onset sepsis in premature infants. Furthermore, modulating gut microbiota with dietary approaches may improve intestinal dysbiosis commonly seen in patients with obesity-associated metabolic disorders. Supplementation with a butyrate-producing bacterial stain might be used to increase energy expenditure, improve insulin sensitivity, and to help control obesity and metabolic syndrome.