白藜芦醇对红色毛癣菌和烟曲霉菌抑菌作用比较

目的 比较白藜芦醇（resveratrol,Res）对红色毛癣菌（Trichoph yton rubrum,T.rubrum）和烟曲霉菌（Aspergillus fumigatus,A.fumigatus）体外抑菌作用.方法 按照CLSI M38-P方案的微量肉汤稀释法检测Res对14株T.rubrum和3株A.fumigatus的体外最低抑菌浓度（MIC）,比较亚浓度Res作用下两种真菌在电镜下细胞结构的改变.结果 Res对T.rubrum和A.fumigatus的MIC分别为0.064 mg/ml和0.512 mg/ml,电镜下Res作用后的红色毛癣菌细胞内容物严重缺失,出现大片空白区,空泡大小不一,排列凌乱;烟曲霉菌菌丝出现空白区,内容物排列不整.结论 Res对T.rubrum 体外抑菌浓度MIC低于A.fumigatus,Res对T.rubrum抑菌效果明显,电镜下Res两种真菌的抑菌效果明显.     

白藜芦醇对须癣毛癣菌体外抑制作用和超微结构初步研究

目的 体外研究2017年9月～2018年3月收集的15株须癣毛癣菌(trichophyton mentagrophytes,T.mentagrophytes)对白藜芦醇(resveratrol,Res)的药物敏感性及超微结构的影响,推测白藜芦醇可能的抑菌机理。方法 参考美国临床和实验室标准化研究所(clinical and laboratory standards institute,CLSI)M38-A2方案,采用微量液基稀释法测定对照组及实验组不同浓度白藜芦醇体外抗须癣毛癣菌的最低抑菌浓度(minimum inhibitory concentration,MIC),及透射电镜下菌体超微结构的变化。结果 白藜芦醇对须癣毛癣菌的MIC₅₀和MIC₉₀分别为0.064 mg/ml,0.128 mg/ml; 实验组的菌体结构在透射电镜下较正常对照组变化明显:细胞壁剥离、缺如,质壁分离现象严重,且明显肿胀、变形,细胞膜严重皱缩,核膜暴露并膨大,断裂、溶解消失,细胞器完全消失,呈空泡化改变。结论白藜芦醇对须癣毛癣菌有明显的抑制作用,有治疗皮肤癣菌病的应用潜力。     

不同辐射功率的微波对红色毛癣菌酶活性的影响

目的 观察不同辐射功率微波对红色毛癣菌β-（1,3）-D-葡聚糖合成酶及琥珀酸脱氢酶活性的影响,探讨其抗真菌作用机制。 方法 将经过形态学鉴定的红色毛癣菌分为实验组及对照组,采用2450 MHz医用微波进行辐射,将实验组按照输出功率分为20 W、40 W、60 W、80 W 4个亚组,每个亚组辐射时间均为15 min,辐射9次。辐射完成后置于27 ℃恒温箱培养。对照组接种完成后立即置于同一恒温箱,不进行任何功率的微波辐射。30 d后提取真菌蛋白酶,采用ELISA法(酶联免疫法）测定标本中β-（1,3）-D-葡聚糖合成酶及琥珀酸脱氢酶活性水平。 结果 随着辐射功率的增加,酶的活性逐渐降低,当输出功率为80 W时,β-（1,3）-D-葡聚糖合成酶及琥珀酸脱氢酶活性分别为（0.730±0.74）U/ml、（1.828±1.774）U/L,与其他3个亚组及对照组比较,80 W组的酶活性显著降低（P<0.05）。 结论 微波对红色毛癣菌酶活性具有抑制作用,并随着辐射功率增大而增强,呈剂量依赖性;微波可在体外诱导红色毛癣菌琥珀酸脱氢酶及β-（1,3）-葡聚糖合成酶活性减弱,导致真菌细胞壁完整性及三羧酸循环被破坏,进而死亡。此外,测定温度变化可能有助于阐明微波的生物效应。     

白藜芦醇对葡萄球菌标准株抑菌作用研究

目的 探讨白藜芦醇(resveratrol,简称RES)对金黄色葡萄球菌抑菌作用。方法 以金黄色葡萄球菌标准株ATCC 25923(金葡菌标准株)作为研究主体检测RES对其的最低抑菌浓度(MIC),绘制不同浓度RES作用下金黄色葡萄球菌的生长曲线。结果 RES对金黄色葡萄球菌标准株MIC为0.256 mg/ml; 在RES浓度为1/4 MIC和1/2 MIC时,生长明显受抑,生长曲线不典型,对数生长期比正常对照组减缓; RES浓度为1MIC和2MIC时金黄色葡萄球菌完全受抑制,生长曲线完全失去正常生长状态,趋于平缓。结论 RES对金黄色葡萄球菌标准株抑制作用明显。     

低温等离子体激活过硫酸盐灭活红色毛癣菌生物膜

目的研究低温等离子体激活过硫酸盐溶液对红色毛癣菌生物膜杀灭效果。方法采用低温大气压等离子体射流装置灭活红色毛癣菌生物膜。结果红色毛癣菌经96 h培养形成完整的生物膜。大气压低温等离子体射流处理5 min,可完全杀灭红色毛癣菌生物膜。生物膜加水更容易被杀灭,过硫酸钠溶液可以提高低温等离子体射流杀灭红色毛癣菌生物膜的效果。结论低温等离子体射流可以杀灭红色毛癣菌生物膜,过硫酸盐可有效提高等离子体灭活红色毛癣菌生物膜的效率。     

红色毛癣菌在7种培养基上的生物学特性

红色毛癣菌（Trichophyton rubrum）是最常见的亲人性致病性皮肤癣菌,了解它的生物学特性,如产色、产孢情况等对红色毛癣菌引起的皮肤癣菌病的诊断和治疗有十分重要的意义。红色毛癣菌被认为很难产孢,特别是大分生孢子［1］。且常发生产色变异,非产色株逐渐增多［2］。作者自2009年7月至2011年12月通过对红色毛癣菌在7种培养基上的菌落形态、镜下产孢情况的观察,菌落直径测量等,探讨红色毛癣菌在不同培养基条件下生物学性状的改变。报道如下。     

ROS在长脉冲1064nm激光体外照射红色毛癣菌中的表达及作用

目的探讨活性氧簇(ROS)在长脉冲1 064 nm激光体外照射临床分离的红色毛癣菌Y和红色毛癣菌N中的表达变化及其作用。方法应用长脉冲Nd:YAG 1 064 nm激光分别以200 J/cm2,400 J/cm2、600 J/cm2能量照射红色毛癣菌Y菌落(分离自临床激光治疗有效的病甲)和红色毛癣菌N菌落(分离自临床激光治疗无效的病甲),未行激光照射组为对照组,观察红色毛癣菌Y和N的菌落在激光照射第1、3、5、7天的生长曲线变化,同时应用比色法检测ROS(H2O2、OH-、O2-)表达水平。结果红色毛癣菌Y随着激光照射能量的增加,生长曲线下移,在激光照射能量为600 J/cm2时,菌落停止生长,其ROS表达水平随照射剂量的增加而升高;红色毛癣菌N随着激光照射能量的增加,各激光能量组生长曲线接近重合,菌落生长不受影响,其ROS表达水平随照射剂量的增加无明显变化。结论 ROS可能在长脉冲1 064 nm激光治疗红色毛癣菌甲真菌病中发挥了作用。     

MALDI-TOF MS自建库在红色毛癣菌感染中的临床快速诊断价值

目的建立并评价实验室自建的红色毛癣菌基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)数据库的可行性。方法将红色毛癣菌标准菌株ATCC 28188用沙保罗葡萄糖琼脂(SDA)平板28℃培养5d,分别用双甲酸夹心法和甲酸提取法作为蛋白提取方法,利用MALDI-TOF MS对标准菌株进行质谱数据采集,建立2种不同蛋白提取方法的菌株数据库"双甲酸夹心法自建库"和"甲酸提取法自建库";并用2种蛋白提取方法对21株红色毛癣菌临床分离株进行蛋白提取后,分别选取"双甲酸夹心法自建库+Bruker商品库"、"甲酸提取法自建库+Bruker商品库"和"Bruker商品库"做质谱鉴定,从而对各数据库的鉴定效果进行评价。结果"甲酸提取法自建库+Bruker商品库"对21株红色毛癣菌临床分离株的鉴定得分显著高于其余两组,差异有统计学意义(P<0.05),匹配率为21/21;"Bruker商品数据库"与"Bruker商品数据库+双甲酸夹心法自建库"的鉴定得分比较差异无统计学意义(P>0.05)。结论本实验室建立的"甲酸提取法自建库+Bruker库"对红色毛癣菌的鉴定能力好,适用于临床微生物实验室。与待测菌统一培养条件所建立的数据库丰富了原有的数据库信息,使待测菌的鉴定更为准确。双甲酸夹心法操作简便,但对红色毛癣菌蛋白提取的效果欠佳。     

微波辐射对几种常见表皮癣菌杀灭或抑制效应的实验研究

目的探讨微波辐射对红色毛癣菌、犬小孢子菌、须癣毛癣菌杀抑的效应。方法采用ME-7250型、频率2450MHz的医用微波仪，分别以输出功率为20，40，60w的微波，辐射接种后的红色毛癣菌、犬小孢子菌、须癣毛癣菌，并对其生长情况进行实验室观察。将接种的红色毛癣菌、犬小孢子菌、须癣毛癣菌的试管，分别按不同的辐射时间、辐射次数分为辐射10，15，20min三大组；每一辐射时间档中分为辐射1，3，6，9次的组别。按设计分组辐射完成后，置27℃恒温箱内。30d后，观察试管内菌落的生长情况，并在显微镜下对其生物学形态进行观察。结果输出功率20w的微波辐射无明显的杀抑效应。输出功率40w的微波辐射10min，15min有抑菌的效应；辐射20min有较明显抑菌的效应。输出功率60w的微波辐射10min，有较明显抑菌的效应，辐射15min，20min显现杀菌效应。结论输出功率40w的微波辐射有抑菌的效应。输出功率60w、频率2450MHz的微波辐射红色毛癣菌、犬小孢子菌、须癣毛癣菌，有明显的抑制生长和杀菌作用，效应随辐射强度的增大而增强。     

白藜芦醇体外抗白假丝酵母菌生物膜作用的初步研究

目的 研究白藜芦醇对体外白假丝酵母菌生物膜的影响.方法 采用XTT减低法评价白藜芦醇对白假丝酵母菌生物膜的影响;通过倒置显微镜、扫描显微镜观察该药对白假丝酵母菌生物膜的形态学影响.结果 白藜芦醇对白假丝酵母菌生物膜的SMIC50,SMIC80分别为128,256 μg/ml;当白藜芦醇浓度为256 μg/ml时对白假丝酵母菌的早期黏附及菌丝生长有抑制作用.结论 白藜芦醇对体外白假丝酵母菌生物膜有显著的抑制作用.     

白藜芦醇抑菌作用及抑菌机制研究进展

白藜芦醇（resveratrol，RES）是一种抵制真菌侵袭时植物产生的具有多种生物学活性、对多种微生物有抑制作用的抗毒素物质。近几年研究表明 RES对各种微生物具有明显的抑制作用，该文对 RES干扰细胞壁蛋白质合成、细胞膜损伤和通过 RsbA介导的抑菌因子形成的抑菌机制进行了综述分析。     

In Vitro Antifungal Activity of Ankaferd Blood Stopper Against Candida albicans

Background

Candida albicans is a memeber of the oral flora that can lead to various complications in immunosupresive patients after oral surgery processes. Ankaferd Blood Stopper® (ABS) is a medical plant extract that is safe to use in patients with dental surgery bleedings in Turkey.

Objective

The study evaluated the antifungal activity of ABS medicinal plant extract against C albicans using the agar diffusion and broth microdilution methods.

Methods

The plant extract antifungal activity was assessed in vitro either by applying the ABS extract directly and by applying different concentrations of ABS onto Candida culture. For these experiments, an agar diffusion method was used. To determine the minimum inhibitory concentration (MIC), a broth microdilution method was used.

Results

Different volumes of the active substance (10, 20, 30, and 40 μL) were applied onto Candida (0.5 McFarland solution) cultivated plate; Candida growth was inhibited in accordance with the volumes of ABS. However, when various dilutions of ABS (1:2, 1:20, 1:40, and 1:80) were added as drops containing 20 μL, no antifungal effects were found. No MIC values were identified using broth microdilution. When different dilutions of ABS containing 100 μL of 0.5 McFarland solution of C albicans were cultured depending on the time (10, 20, 30, and 40 minutes), the effect of the duration was not significant.

Conclusion

The various tests were carried out to investigate antifungal effects of ABS on Candida, but none were found.     

Antifungal Activity of Propolis Against Yeasts Isolated From Blood Culture: In Vitro Evaluation

Background: Due to the failure of available antifungal agents in the treatment of candidemia and the toxic activities of these drugs, a lot of researches are being conducted to develop new nontoxic and effective antifungal agents for optimal control of fungal pathogens. The aim of this study is to evaluate the in vitro antifungal activity of propolis against yeasts isolated from the blood cultures of intensive care unit patients. Methods: Seventy‐six strains were included in this study. The in vitro antifungal activity of propolis, fluconazole (FLU), and itraconazole (ITR) was investigated by the microdilution broth methods (CLSI guidelines M27‐A3 for yeast). The propolis sample was collected from Kayseri, Turkey. Results: Of the 76 isolates, 33 were identified as Candida albicans while 37 were C. parapsilosis, three were C. tropicalis, and three were identified as C. glabrata. The geometric mean range for MIC (μg/ml) with regard to all isolates was 0.077 to 3 μg/ml for FLU and ITR, and 0.375 to 0.70 μg/ml for propolis. It was shown that propolis had significant antifungal activity against all Candida strains and the MIC range of propolis was determined as 0185 to 3 μg/ml. Conclusion: This study demonstrated that propolis had significant antifungal activity against yeasts isolated from blood culture compared with FLU and ITR. The propolis MIC in azole‐resistant strains such as C. glabrata was found lower than the FLU MIC.     

Comparison of the In Vitro Activities of Newer Triazoles and Established Antifungal Agents against Trichophyton rubrum

One hundred eleven clinical Trichophyton rubrum isolates were tested against 7 antifungal agents. The geometric mean MICs of all isolates were, in increasing order: terbinafine, 0.03 mg/liter; voriconazole, 0.05 mg/liter; posaconazole, 0.11 mg/liter; isavuconazole, 0.13 mg/liter; itraconazole, 0.26 mg/liter; griseofulvin, 1.65 mg/liter; and fluconazole, 2.12 mg/liter.     

Antifungal Activity of Micafungin in Serum

We have evaluated the antifungal activity of micafungin in serum by using the disk diffusion method with serum-free and serum-added micafungin standard curves. Serum samples from micafungin-treated patients have been shown to exhibit adequate antifungal activity, which was in proportion to both the applied dose and the actual concentration of micafungin measured by high-performance liquid chromatography. The antifungal activity of micafungin in serum was also confirmed with the broth microdilution method.Micafungin has been shown to bind to serum proteins at a level of 99.8% (13). If the unbound drug contributes to its pharmacological activity (the free-drug hypothesis), only 0.2% of total micafungin would be available to exert antifungal activity in the presence of serum, and the MIC for micafungin in vitro would increase 500-fold. However, several studies have shown that this ratio varies from 4- to 267-fold (6, 7, 11), indicating that the antifungal activities of micafungin in serum may not follow the free-drug hypothesis; instead, observed activities are mostly superior to those predicted. Furthermore, it remains unclear whether these results can be applied to micafungin in a patient''s serum. To address this issue, we collected serum samples from micafungin-treated patients and examined the relationship between micafungin concentration and its in vitro antifungal activity in serum.This study was approved by the institutional review board, and informed consent was obtained from each patient. Patients with hematologic malignancies, admitted into Osaka University Medical Hospital, were administered micafungin at a dose of 50 to 300 mg/body once daily. The efficacy of prophylaxis was defined as the absence of proven, probable (EORTC-IFICG/NIAID-MSG) (1), or suspected (unexplained persistent fever and clinical findings) (10) fungal infection, through the end of therapy. The efficacy of the drug for suspected fungal infections was indicated by improvement of persistent fever and clinical findings.Blood samples were collected from patients just before (trough) and after (peak) micafungin infusion, at least 4 days after initiating treatment (steady state) (2). Micafungin concentration in serum was measured by high-performance liquid chromatography (HPLC) (9, 12). The disk diffusion method was performed according to National Committee for Clinical Laboratory Standards (NCCLS) M44-A guidelines (5). To obtain standard curves, we prepared two types of serial dilution disks impregnated with micafungin standard solution, one in RPMI 1640 (serum-free standard) and the other in heat-inactivated serum from volunteers (serum-added standard). Disks were applied to Sabouraud dextrose agar plates inoculated with Candida albicans FP633, a clinical isolate kindly provided by Astellas Pharma Inc., Tokyo, Japan. The diameter of the area of complete growth inhibition (inhibitory zone) was measured. Similarly, disks were impregnated with serum samples collected from patients, and the inhibitory zones were measured. The determination of antifungal activity of micafungin in a patient''s serum was based on two standard curves, as described above. To determine the inhibitory titer in a patient''s serum, we utilized the broth microdilution method based on the guidelines in NCCLS M27-A2 (4). Serum from a patient was serially diluted twofold with serum from a volunteer, supplemented with 20 mM HEPES, and inoculated with C. albicans FP633. MIC was defined as the lowest concentration where no visible growth was observed. Serum inhibitory titers were defined as the highest dilution of serum that completely inhibited fungal growth.In all seven patients, micafungin was effective for prophylaxis or treatment against fungal infections (Table ​(Table1).1). Serum peak concentrations (C_max) of micafungin (measured by HPLC) ranged from 5.59 to 37.1 μg/ml at a dose of 50 to 300 mg/body and closely correlated with both daily dose and dosage in terms of body weight (Table ​(Table2).2). Standard curves were prepared from both serum-free and serum-added micafungin standard disks (Fig. ​(Fig.1).1). The antifungal activity of micafungin remained intact in serum: 20 to 50% (by measured value) or 25 to 30% (by standard curve).Open in a separate windowFIG. 1.Estimation of micafungin concentration in serum samples from patient no. 5, using the disk diffusion method. (A) Concentration measured using HPLC, 16.4 μg/ml. (B) Concentration estimated from the serum-free micafungin standard curve, 6.0 μg/ml. (C) Concentration estimated from the serum-added micafungin standard curve, 22.1 μg/ml. Ratio of concentration B to concentration A (%) = 6.0/16.4 × 100 = 37. Ratio of concentration C to concentration A (%) = 22.1/16.4 = 134.8.

TABLE 1.

Patient background