罗红霉素与乙酰螺旋霉素对眼部金黄色葡萄球菌生物膜的影响

目的:比较罗红霉素与乙酰螺旋霉素对眼部金黄色葡萄球菌生物膜的影响及与环丙沙星合用的抗菌协同作用。方法:用0.22μm微孔膜构建金黄色葡萄球菌生物膜模型;测定罗红霉素、乙酰螺旋霉素及环丙沙星的最低抑菌浓度(MIC)值;银染金黄色葡萄球菌生物膜,扫描电镜(SEM)观察生物膜形态结构,连续稀释法进行活菌计数。结果:生物膜(BF)可在7 d内稳定形成,1/16MIC、1/4MIC浓度罗红霉素显著减少单用环丙沙星组中的BF活菌数(P<0.05),乙酰螺旋霉素没有明显作用。结论:罗红霉素能显著提高环丙沙星对BF中金黄色葡萄球菌的抗菌活性。     

吲哚菁绿光热治疗耐甲氧西林葡萄球菌感染的研究

目的　探讨吲哚菁绿（ICG）的光热治疗（PTT）性能及对耐甲氧西林葡萄球菌的杀灭效果。方法　利用紫外和荧光光谱对ICG的光物理性质进行表征;测定不同质量浓度ICG（0、12.5、25、50、100和200 mg/L）的光热升温曲线,评估ICG的光热转化性能;取小鼠乳腺癌4T1细胞与不同质量浓度的ICG溶液（0、50、100、200和500 mg/L）混合,通过MTT实验检测ICG的细胞毒性;取1×1010 CFU/mL的耐甲氧西林的金黄色葡萄球菌加入到96孔板中,将实验分为7组：PBS组、ICG组（500 mg/L）、激光照射组（1.5 W/cm2的808 nm激光照射10 min）、ICG+0.33 W/cm2激光照射组、ICG+0.66 W/cm2激光照射组、ICG+1 W/cm2激光照射组、ICG+1.5 W/cm2激光照射组,观察并记录存活的菌落数,分析基于ICG的PTT杀菌效果。结果　紫外吸收光谱证实ICG在808 nm处具有较强的光吸收能力;ICG溶液（质量浓度为200 mg/L）经功率密度为1.5 W/cm2的808 nm近红外激光照射10 min后,温度可升高23.3 ℃,而纯水的温度仅升高了4.8 ℃。ICG不同质量浓度组即50、100、200、500 mg/L组的细胞生存率分别为81.87%±2.69%、81.47%±2.94%、82.92%±2.61%、80.44%±2.98%,组间差异无统计学意义（F=0.402,P＞0.05）。不同功率密度激光照射组即0.33、0.66、1、1.5 W/cm2组的细胞生存率分别为97.21%±1.59%、94.92%±1.98%、93.89%±1.38%、93.03%±2.31%,组间差异无统计学意义（F=2.864,P＞0.05）。杀菌实验中,与PBS组比较,ICG+激光照射组随着激光功率密度的升高,细菌存活数量逐渐下降,差异有统计学意义（F=133.800,P＜0.01）。结论　ICG具有良好的生物相容性和光热治疗性能,在近红外激光照射下对耐甲氧西林葡萄球菌具有较强的杀灭效果,具有较好的临床转化应用价值。     

海洋链霉菌Streptomyces sp. S598中抗菌活性产物的研究

目的 对海洋链霉菌Streptomyces sp. S598固体发酵提取物的抗菌成分进行研究。方法 采用葡聚糖凝胶Sephadex LH-20、反相柱色谱、硅胶柱层析及半制备HPLC等方法分离纯化该菌株的活性次级代谢产物,并通过ESI-MS、NMR等波谱技术结合文献对比鉴定其结构。结果 从10L固体发酵提取物中分离得到5个单体化合物,分别鉴定为缬氨霉素(1)、二活菌素(2)、亚油酸(3)、亚油酸甲酯(4)和油酸(5)。结论 海洋链霉菌Streptomyces sp. S598能代谢产生具有多种生物活性的化合物。化合物1对MRSA 28300和白念珠菌(ATCC10231)的MIC为1μg/mL,化合物2具有较强的广谱抗细菌活性,对肺炎链球菌、流感嗜血菌的MIC为0.125μg/mL,尤其具有显著的抗MRSA的活性,对MRSA     

Description of Methicillin-Susceptible Staphylococcus aureus Clonal Complex 30 Related to the Pandemic Phage Type 80/81 Isolated from Patients in Three Tertiary Hospitals in Jos,North Central Nigeria

ObjectiveThe prevalence of phage 80/81 Staphylococcus aureus strains, the pandemic strains that were dominant in the 1950s, had declined in the 1960s and 1970s. However, these strains have reemerged in some countries in recent years. This study investigated the antibacterial resistance, virulence, and the genetic backgrounds of CC30-MSSA isolates obtained from patients in three tertiary hospitals.Materials and MethodsTwenty-two CC30-MSSA isolates cultured from different clinical samples were investigated using antibiotic sensitivity testing, spa typing, multilocus sequence typing, and DNA microarray analysis.ResultsAll 22 isolates were susceptible to vancomycin (MIC ≤2 μg/mL), teicoplanin (MIC ≤2 μg/mL), and cefoxitin but were resistant to penicillin G (n = 22; 100.0%), tetracycline (n = 12; 54.5%), ciprofloxacin (n = 15; 68.2%), cadmium acetate (n = 22; 100%), mercuric chloride (n = 13; 59.1%), and ethidium bromide (n = 3; 13.6%). The isolates belonged to sequence type, ST30, and five spa types: t012 (n = 12; 54.5%), t019 (n = 5; 22.7%), t017 (n = 2; 9.1%), t037 (n = 2; 9.1%), and t318 (n = 1; 4.5%). All 22 isolates were positive for agrIII, cap8, clfA, clfB, icaA, icaC, icaD, cna, and staphylococcal enterotoxin gene clusters (seg, sei, sem, sen, seo, seu). Eight isolates carried lukS-PV and lukF-PV that code for Panton-Valentine leukocidin.ConclusionThe current CC30-MSSA isolates share phenotypic and genotypic characteristics with the pandemic phage 80/81 isolates that were common in the 1950s and 1960s. Continued surveillance is recommended to keep abreast of the changing epidemiology of S. aureus causing healthcare and community-associated infections.     

SPA-ELISA检测棕果蝠血清冠状病毒抗体的研究

目的 建立一种敏感、简便的检测蝙蝠血清冠状病毒抗体的方法.方法 利用葡萄球菌A蛋白(SPA)能够与某些哺乳动物IgG抗体Fc段非特异性结合的特点,对市售人冠状病毒抗体ELISA试剂盒进行改造,建立SPA-ELISA法,使其适用于蝙蝠血清冠状病毒抗体的检测,并对采集到的55份棕果蝠血清冠状病毒抗体进行检测.结果 用SPA-ELISA方法对人冠状病毒试剂盒中阳性与阴性对照、SARS病人恢复期血清、空白对照的检测都得到理想的结果,并从55份棕果蝠血清中检测出2例阳性,阳性率为3.64％(2/55),中和试验进一步证实了结果的真实性.结论 所建立的方式适用于检测棕果蝠血清冠状病毒抗体.     

Functionalization of Se-Te Nanorods with Au Nanoparticles for Enhanced Anti-Bacterial and Anti-Cancer Activities

The use of medical devices for therapeutic and diagnostic purpose is globally increasing; however, bacterial colonization on therapeutic devices can occur, causing severe infections in the human body. It has become an issue for public health. It is necessary to develop a nanomaterial based on photothermal treatment to kill toxic bacterial strains. Appropriately, high photothermal conversion and low-cost powerful photothermal agents have been investigated. Recently, gold nanocomposites have attracted great interest in biological applications. Here, we prepared rod-shaped Se-Te@Au nanocomposites of about 200 nm with uniform shape and surface-coated with gold nanoparticles for the first time showing high anti-bacterial and anti-cancer activities. Se-Te@Au showed proper structural consistency and natural resistance to bacterial and cancer cells. The strong absorption and high photothermal conversion efficacy made it a good photothermal agent material for the photothermal treatment of bacterial and cancer cells. The Se-Te@Au rod showed excellent anti-bacterial efficacy against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus, with highest recorded inhibition zones of 25 ± 2 mm and 22 ± 2 mm, respectively. More than 99% of both types of strains were killed after 5 min with a near-infrared (NIR) laser at the very low concentration of 48 µg/mL. The Se-Te@Au rod’s explosion in HeLa cells was extensively repressed and demonstrated high toxicity at 100 µg/mL for 5 min when subjected to an NIR laser. As a result of its high photothermal characteristics, the exceptional anti-bacterial and anti-cancer effects of the Se-Te@Au rod are considerably better than those of other methods previously published in articles. This study could open a new framework for sterilization applications on the industrial level.     

1996～2001年内科、外科、ICU和门诊患者分离的金黄色葡萄球菌耐药性分析

目的 通过对1996～2001年60家三级甲等医院不同科别住院患者和门诊患者分离的金黄色葡萄球菌的耐药性分析，探讨不同科别来源菌株耐药率间的差别及变迁。方法 药敏试验采用纸片扩散法，用WHONET5软件分析结果。结果 6年间内科住院患者分离的金黄色葡萄球菌对苯唑陛西林的耐药率维持在40％；磺胺甲恶唑／甲氧苄啶(SMZ／TMP)和氯霉素的耐药率从1998年的51．4％和39．6％降低到2001年的36．2％和23．6％。外科住院患者分离菌株对苯唑西林的耐药率从1996年的26．3％增加到2001年的45．9％；庆大霉素和环丙沙星耐药率从1996年的24．6％和17．5％增到2001年的43．5％和43．1％。ICU患者分离的大多数菌株对苯唑西林和环丙沙星耐药。门诊患者分离菌株对苯唑西林的耐药率从1996年的17．2％增加到2001年的24．9％；环丙沙星的耐药率超过30％；SMZ/TMP的耐药率从1998年的61％降低到2001年的38．3％。结论 调查不同科别住院患者和门诊患者来源的金黄色葡萄球菌对常用抗生素耐药性的变迁和现状，对于临床抗感染治疗的经验用药具有一定的指导意义。     

头孢西酮钠对临床分离细菌感染小鼠的保护作用

目的 探讨头孢西酮钠对临床分离菌株感染小鼠的保护作用。方法 给小鼠腹腔注射临床分离的金黄色葡萄球菌、铜绿假单胞菌和大肠埃希菌，感染后皮下注射头孢西酮钠，观察记录感染后小鼠的生存率。结果 头孢西酮钠10mg／kg、20mg／kg和40mg/kg能显著降低中间葡萄球菌R1725株、金黄色葡萄球菌R1743株、铜绿假单胞菌R1620株、铜绿假单胞菌R1598株、大肠埃希菌R1598株、大肠埃希菌W1867株和D群肠球菌W1999株感染小鼠的死亡率。结论 头孢西酮钠对临床分离的金黄色葡萄球菌、铜绿假单胞菌和大肠埃希菌感染小鼠有显著的保护作用。     

人参皂苷Rg_1通过作用于炎性因子和糖皮质激素受体减少金葡菌对肺上皮细胞的损伤(英文)

本文旨在探讨人参皂苷Rg_1体外对金葡菌感染肺上皮细胞所致病变的作用及其可能的机制。实验采用体外大鼠原代肺上皮细胞感染模型。RT-PCR和Western blot方法观察肺细胞中integrinβ1,NF-κB和糖皮质激素受体(GR)等相关因子的表达。结果表明人参皂苷Rg_1可以明显抑制金葡菌感染后肺上皮细胞整合素integrinβ1的表达,下调炎性因子NF-κB,ICAM-1,TNF-α,IL-2和IL-6,上调GR的表达。人参皂苷Rg_1可以明显抑制金葡菌感染肺上皮细胞后的炎性因子,从而对肺脏起到一定的保护作用。     

赶黄草水煎液对金黄色葡萄球菌和耐甲氧西林金黄色葡萄球菌生物膜形成的影响

目的 探究赶黄草水煎液在体外对金黄色葡萄球菌(SA)和耐甲氧西林金黄色葡萄球菌生物膜(MRSA)形成的影响。方法 采用微量肉汤稀释法测定赶黄草水煎液对金黄色葡萄球菌和耐甲氧西林金黄色葡萄球菌的最小抑菌浓度(MIC)和最小杀菌浓度(MBC),根据MIC和MBC绘制杀菌曲线,采用结晶紫染色法和激光共聚焦观察赶黄草水煎液对SA和MRSA生物膜形成的影响,并通过测定胞外多糖和胞外DNA的含量研究赶黄草水煎液破坏SA和MRSA生物膜的作用方式。结果 赶黄草水煎液对SA的MIC和MBC分别为1.36和2.71 mg/mL,对MRSA的MIC和MBC为2.71和5.73 mg/mL;赶黄草水煎液可使SA和MRSA均生长受到抑制,抑制生物膜的形成、减少胞外多糖和胞外DNA的释放。结论 赶黄草水煎液对SA和MRSA具有良好的抑菌作用,可通过抑制胞外多糖和DNA的分泌破坏生物膜的形成。