Synthesis of Silver Modified Bioactive Glassy Materials with Antibacterial Properties via Facile and Low-Temperature Route

There is an increasing clinical need to develop novel biomaterials that combine regenerative and biocidal properties. In this work, we present the preparation of silver/silica-based glassy bioactive (ABG) compositions via a facile, fast (20 h), and low temperature (80 °C) approach and their characterization. The fabrication process included the synthesis of the bioactive glass (BG) particles followed by the surface modification of the bioactive glass with silver nanoparticles. The microstructural features of ABG samples before and after exposure to simulated body fluid (SBF), as well as their ion release behavior during SBF test were evaluated using infrared spectrometry (FTIR), ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), electron microscopies (TEM and SEM) and optical emission spectroscopy (OES). The antibacterial properties of the experimental compositions were tested against Escherichia coli (E. coli). The results indicated that the prepared ABG materials possess antibacterial activity against E. coli, which is directly correlated with the glass surface modification.     

氮掺杂纳米TiO_2抗菌剂的体外细胞毒性研究

目的：通过对高可见光活性氮掺杂纳米二氧化钛（纳米N-TiO2）抗菌剂体外细胞毒性的测定,初步评价纳米N-TiO2抗菌剂的生物安全性。方法：采用含不同浓度纳米N-TiO2抗菌剂的培养液培养人牙周膜成纤维细胞,另设空白对照组和阳性对照组。在显微镜下观察细胞形态及数量,MTT法测定各组细胞培养1、3和5d的吸光度值,并计算细胞的相对增值率,从而判断细胞毒性的级别。结果：各观察期,实验组的人牙周膜成纤维细胞生长良好,形态正常,表现出较高的细胞增值率,1d为109.67±8.5、3d为109.99±7.0、5d为102.53±6.4;与空白对照组比较差异无统计学意义;实验组的吸光度值在各个时间段与空白对照组比较差异均无统计学意义（P〉0.05）,且随培养时间的延长,吸光度值增大。结论：纳米N-TiO2抗菌剂实验期内无细胞毒性,生物安全性较好。     

8-Hydroxyquinolines are bactericidal against Mycobacterium tuberculosis

There is an urgent need for new treatments effective against Mycobacterium tuberculosis, the causative agent of tuberculosis. The 8-hydroxyquinoline series is a privileged scaffold with anticancer, antifungal, and antibacterial activities. We conducted a structure–activity relationship study of the series regarding its antitubercular activity using 26 analogs. The 8-hydroxyquinolines showed good activity against M. tuberculosis, with minimum inhibitory concentrations (MIC90) of <5 μM for some analogs. Small substitutions at C5 resulted in the most potent activity. Substitutions at C2 generally decreased potency, although a sub-family of 2-styryl-substituted analogs retained activity. Representative compounds demonstrated bactericidal activity against replicating M. tuberculosis with >4 log kill at 10× MIC over 14 days. The majority of the compounds demonstrated cytotoxicity (IC₅₀ of <100 μM). Further development of this series as antitubercular agents should address the cytotoxicity liability. However, the 8-hydroxyquinoline series represents a useful tool for chemical genomics to identify novel targets in M. tuberculosis.     

Biocatalytic synthesis of diaryl disulphides and their bio-evaluation as potent inhibitors of drug-resistant Staphylococcus aureus

Staphylococcus aureus is a WHO Priority II pathogen for its capability to cause acute to chronic infections and to resist antibiotics, thus severely impacting healthcare systems worldwide. In this context, it is urgently desired to discover novel molecules to thwart the continuing emergence of antimicrobial resistance. Disulphide containing small molecules has gained prominence as antibacterials. As their conventional synthesis requires tedious synthetic procedure and sometimes toxic reagents, a green and environmentally benign protocol for their synthesis has been developed through which a series of molecules were obtained and evaluated for antibacterial activity against ESKAPE pathogen panel. The hit compound was tested for cytotoxicity against Vero cells to determine its selectivity index and time-kill kinetics was determined. The activity of hit was determined against a panel of S. aureus multi-drug resistant clinical isolates. Also, its ability to synergize with FDA approved drugs was tested as was its ability to reduce biofilm. We identified bis(2-bromophenyl) disulphide ( 2t ) as possessing equipotent antimicrobial activity against S. aureus including MRSA and VRSA strains. Further, 2t exhibited a selectivity index of 25 with concentration-dependent bactericidal activity, synergized with all drugs tested and significantly reduced preformed biofilm. Taken together, 2t exhibits all properties to be positioned as novel scaffold for anti-staphylococcal therapy.     

Discovery of a new family of heterocyclic amine linked plastoquinone analogs for antimicrobial evaluation

A series of aminobenzoquinones, denoted as PQ analogs ( PQ1-13 ), were synthesized by employing a green methodology approach using water as solvent developed by Tandon et al. Subsequently, in vitro antimicrobial potential of all PQ analogs was evaluated in a panel of seven bacterial strains (three gram positive and four gram negative bacteria) and three fungi. The antifungal profile of all PQ analogs indicated that four analogs (while PQ2 , PQ9 , and PQ10 were effective against Candida tropicalis, PQ11 is effective against Candida albicans) have potent antifungal activity. The results revealed that PQ9 showed similar antibacterial activity against Staphylococcus epidermidis compared clinically prevalent antibacterial drugs cefuroxime. PQ11 exhibited the highest antibacterial activity against S. epidermidis, which was about fourfold better than that of cefuroxime. Owing to their outstanding activities, PQ9 and PQ11 were chosen for a further investigation for biofilm and cytotoxicity evaluation. Based on the tests performed, there was a significant positive correlation between inhibition of the biofilm attachment and time. In addition, PQ9 and PQ11 showed cytotoxic effects at high concentrations on Balb/3T3, HaCaT, HUVEC, and NRK-52E cells (>24 and >18 μg/mL, respectively). Thus, two analogs ( PQ9 and PQ11 ) were identified as the hits with the strong antibacterial efficiency against the S. epidermidis with low MIC values.     

2015—2017年德阳市人民医院重症监护室感染病原菌分布及耐药性分析

目的 分析2015-2017年德阳市人民医院重症监护室感染病原菌分布及耐药性,为临床使用抗菌药物提供依据。方法 选取2015年1月-2017年12月临床送检的重症监护室标本中鉴定出的感染病原菌进行菌种鉴定,并对病原菌分布及耐药性进行分析。结果 共分离出4 890株病原菌,标本主要来源于痰液（39.51%）,其中革兰阴性菌3 902株,占79.80%,主要为大肠埃希菌和肺炎克雷伯菌;革兰阳性菌998株,占20.20%,主要为金黄色葡萄球菌和溶血葡萄球菌。金黄色葡萄球菌和溶血葡萄球菌对常用抗菌药物都有一定程度的耐药,对复方新诺明、喹奴普丁/达福普汀的耐药率在10%以下,对万古霉素和利奈唑胺完全敏感,没有耐药性。大肠埃希菌和肺炎克雷伯菌对大部分抗菌药物的耐药率在50%~80%,二者对哌拉西林、头孢西丁、亚胺培南、阿莫西林克拉维酸、哌拉西林/他唑巴坦、替卡西林/棒酸的耐药率较低,均在10%以下。结论 德阳市人民医院重症监护室感染病原菌分布广泛,针对感染性疾病进行用药时,要在使用抗菌药物之前留取相应的标本,且尽量减少或避免长期滥用抗菌药物,避免根据经验用药,以减免耐药性的产生。     

2015—2017年天津市津南区咸水沽医院抗菌药物的使用情况分析

目的 评价和分析天津市津南区咸水沽医院2015-2017年抗菌药物的使用情况及变化趋势,为临床应用抗菌药物的合理性和科学性提供参考依据。方法 从天津市津南区咸水沽医院HIS系统中调取2015-2017年的抗菌药物数据进行回顾性分析,对不同剂型抗菌药物的销售金额、用药频度（DDDs）、日均费用（DDC））和排序比（B/A）等进行统计分析。结果 2015-2017年口服和注射剂型抗菌药物的销售金额均呈逐年上升趋势,2017年,氨基糖苷类的销售金额跃居第1位。头孢丙烯分散片于2016、2017年连续两年销售金额和DDDs排名居首位。口服抗菌药物的DDC值较低。大部分口服抗菌药物的B/A接近于1.00。盐酸莫西沙星注射液于2017年销售金额排名跃居首位,2016-2017年,注射用美罗培南的销售金额位居第2位。甲磺酸左氧氟沙星氯化钠注射液的DDDs排名位居前3位。注射剂型抗菌药物的DDC值一般较高。大部分注射剂型抗菌药物的B/A接近于1.00。结论 天津市津南区咸水沽医院2015-2017年抗菌药物临床应用总体上比较规范和合理,基本符合抗菌药物的用药规律。     

2017年中国医科大学附属盛京医院老年住院患者鲍曼不动杆菌的分布及耐药性分析

目的 对2017年中国医科大学附属盛京医院老年住院患者鲍曼不动杆菌的分布及耐药性进行分析,为临床治疗提供科学指导依据。方法 回顾性分析2017年中国医科大学附属盛京医院老年住院患者鲍曼不动杆菌的标本来源、科室分布及耐药情况。结果 共分离出鲍曼不动杆菌193株,其中165株（85.49%）为多重耐药鲍曼不动杆菌。痰液标本为鲍曼不动杆菌的主要来源。重症监护室、呼吸内科是多重耐药鲍曼不动杆菌分布最多的两个科室。多重耐药鲍曼不动杆菌对大部分抗菌药物严重耐药,其中对头孢唑林、头孢西丁、头孢替坦、头孢噻肟、哌拉西林/他唑巴坦、哌拉西林、呋喃妥因、氨曲南、氨苄西林、阿莫西林/克拉维酸、头孢呋辛、氯霉素、磷霉素、诺氟沙星的耐药率均为100.00%,对替加环素的耐药率最低,为8.50%;非多重耐药鲍曼不动杆菌对大部分抗菌药物敏感。结论 中国医科大学附属盛京医院老年住院患者多重耐药鲍曼不动杆菌感染情况严重,针对老年住院患者建立更加严密的监控机制,加强流行病学资料的采集及干预工作的开展具有重要实践价值。     

2016-2018年天津市第五中心医院感染性疾病病原菌的分布及耐药性分析

目的 探究2016-2018年天津市第五中心医院感染性疾病病原菌的分布及耐药性。方法 回顾性分析2016年1月-2018年12月天津市第五中心医院感染病原菌的分布,并对病原菌进行耐药性检测。结果 3 103株感染病原菌中,革兰阴性菌1 793株（57.78%）,以鲍曼不动杆菌（15.73%）、大肠埃希菌（18.66%）为主,鲍曼不动杆菌对头孢西丁（81.37%）、头孢吡肟（71.15%）具有较高的耐药性,对阿莫西林（30.44%）具有较低的耐药性,大肠埃希菌对头孢他啶（51.77%）、头孢吡肟（46.12%）具有较高的耐药性,对哌拉西林（7.17%）、阿米卡星（5.37%）的耐药性低;革兰阳性菌共1 109株（35.74%）,以肺炎链球菌（9.96%）、金黄色葡萄球菌（16.98%）为主,肺炎链球菌和金黄色葡萄球菌对红霉素、青霉素的耐药性高,对头孢唑啉和左氧氟沙星具有较低的耐药性;真菌共201株（6.48%）,以白假丝酵母菌（2.96%）为主,白假丝酵母菌对伊曲康唑（13.07%）、氟康唑（4.28%）、5-氟胞嘧啶（2.98%）、伏力康唑（2.73%）等抗菌药物的耐药性较低。结论 天津市第五中心医院的感染病原菌主要为条件致病菌,耐药性严重;医院应定期对病原菌进行耐药性分析,并指导医师合理使用抗菌药物。     

2017—2018年天津市宝坻区人民医院血流感染病原菌分布及耐药性分析

目的 探讨天津市宝坻区人民医院血流感染病原菌的分布及耐药性情况,为临床合理用药提供依据。方法 对2017-2018年天津市宝坻区人民医院血流感染病原菌的分布及耐药性进行回顾性分析。结果 共分离出病原菌365株,主要分布在普通内科、呼吸内科和儿科。其中革兰阴性菌228株,构成比为62.47%,主要为大肠埃希菌、肺炎克雷伯菌和鲍曼不动杆菌;革兰阳性菌137株,构成比为35.34%,主要为凝固酶阴性葡萄球菌和金黄色葡萄球菌;真菌8株,构成比为2.19%。大肠埃希菌、肺炎克雷伯菌对头孢菌素类、喹诺酮类和氨基糖苷类等抗菌药物存在不同程度的耐药性,但对酶抑制剂（头孢哌酮/舒巴坦、哌拉西林/他唑巴坦）较为敏感,对碳青霉烯类抗菌药物保持较高敏感性;鲍曼不动杆菌对第3代头孢菌素（头孢曲松、头孢噻肟）的耐药率达到了90%以上,对碳青霉烯类抗菌药物耐药率未超过20%。凝固酶阴性葡萄球菌和金黄色葡萄球菌对万古霉素、利奈唑胺无耐药性。目标性治疗应用抗菌药物中,革兰阴性菌所致血流感染多选择美罗培南（21.20%）、头孢哌酮/舒巴（14.96%）和哌拉西林/他唑巴坦（10.72%）;革兰阳性菌所致血流感染多选择万古霉素（19.45%）。结论 天津市宝坻区人民医院血流感染病原菌主要以革兰阴性菌为主,应加强血流感染病原菌的耐药性监测,以指导抗菌药物的合理使用。