体外棋盘法分析粗糠柴苦素与氟康唑联合抗隐球菌作用

目的应用棋盘法测定以及探究粗糠柴苦素在体外联合氟康唑抗隐球菌是否有增效作用。方法参照微量稀释法(M27-A3)对隐球菌进行氟康唑、粗糠柴苦素单药药敏实验[FLZ、RAT],以及以分数抑菌浓度指数(FICI)为判定指标棋盘法联合药敏实验[FLZ+RAT]。结果粗糠柴苦素对37株隐球菌MIC值范围为32～256μg/mL,在与氟康唑联合作用时,FICI均≤0.50,使氟康唑的MIC值降低了50%～93.75%。结论粗糠柴苦素对隐球菌具有一定的抗真菌作用,同时与氟康唑联合使用能够发挥协同作用,提高氟康唑对隐球菌的敏感性。     

云南省艾滋病患者新生隐球菌药物敏感性与临床分析CSCD

目的了解云南省艾滋病患者中新生隐球菌病的病原分离部位、耐药性及临床治疗效果。方法对2010年1月至2020年12月临床总共分离的424株新生隐球菌,用VITEK2 Compact全自动微生物分析仪鉴定菌种,ATB FUNGUS 3检测5种抗真菌药物的敏感性,并对临床资料进行分析。结果424株新生隐球菌以脑脊液检出比例最高,占62.50%(265/424);血液次之,占30.90%(131/424);第三是痰液,占2.83%(12/424)。424株新生隐球菌对唑类抗真菌药物伊曲康唑和伏立康唑MIC范围均≤2μg/mL,多烯类的两性霉素B MIC范围≤4μg/mL,氟康唑及5-氟胞嘧啶的MIC范围≤64μg/mL。对两性霉素B、氟康唑、5-氟胞嘧啶的敏感性分别为95.28%(404/424)、80.66%(342/424)、75.71%(321/424)。5种抗真菌药物的流行病学折点分别为:5-氟胞嘧啶和氟康唑16μg/mL;两性霉素B、伊曲康唑和伏立康唑0.5μg/mL。结论新生隐球菌对两性霉素B的敏感性较好,而氟康唑及5-氟胞嘧啶在多年的临床用药过程中已慢慢出现非敏感菌株,伊曲康唑和伏立康唑MIC范围≤2μg/mL。新生隐球菌药敏试验结果为临床医生用药提供参考依据。新生隐球菌病治疗首选两性霉素B与5-氟胞嘧啶联合治疗。隐球菌作为临床重要的致病真菌,实验室及临床均应给予高度重视。     

广西地区隐球菌感染的临床特征、菌种鉴定及体外抗真菌药物敏感性CSCD

目的分析广西地区隐球菌感染的临床特征、致病菌种鉴定及其体外药物敏感性。方法收集86例确诊隐球菌病患者(14例为HIV阳性,72例为HIV阴性)中分离出103株隐球菌及其患者资料并对其临床特征进行分析,使用MALDI-TOF MS和ITS区测序分子鉴定方法,92株被鉴定为新生隐球菌grubii变种,11株被鉴定为格特隐球菌。使用CLSI M27-A4方法对菌株进行常用抗真菌药物氟康唑、两性霉素B、5-氟胞嘧啶、伊曲康唑、伏立康唑、泊沙康唑和艾沙康唑体外药物敏感性测试。结果①86例患者(男性59名,女性27名),年龄为21~84岁,其中55人无基础疾病,31人有基础疾病。②由于目前对于隐球菌尚无泊沙康唑、艾沙康唑和两性霉素B的折点,因此参考了念珠菌属的数据,所有菌株对大多数抗真菌药物敏感。抗真菌药物对新生隐球菌grubii变种最低抑菌浓度范围为:氟康唑0.05~4μg/mL,两性霉素B 0.25~1μg/mL,5-氟胞嘧啶0.0625~2μg/mL,伊曲康唑0.0625~0.25μg/mL,伏立康唑0.0078~0.25μg/mL,泊沙康唑0.0313~0.5μg/mL,艾沙康唑0.0020~0.125μg/mL。抗真菌药物对格特隐球菌最低抑菌浓度范围为:氟康唑1~16μg/mL,5-氟胞嘧啶0.125~1μg/mL,两性霉素B 0.25~1μg/mL,伊曲康唑0.0625~0.25μg/mL,伏立康唑0.0156~0.125μg/mL,泊沙康唑0.0156~0.25μg/mL,艾沙康唑0.0078~0.125μg/mL。结论MALDI-TOF MS是一种快速可靠的鉴定隐球菌的方法。广西地区分离隐球菌对临床抗真菌药物敏感,抗真菌药敏试验有助于早期发现耐药菌株,对有效地治疗隐球菌病具有重要意义。     

新生隐球菌感染流行病学现状及耐药机制相关研究进展

新生隐球菌是一种广泛存在于环境中的酵母类真菌,主要侵犯中枢神经系统引起隐球菌性脑膜炎。HIV感染是导致隐球菌感染的主要危险因素之一,但近年来关于非HIV患者隐球菌感染的报道不断增加。体外药敏试验证实大部分新生隐球菌对棘白菌素类药物具有内在抗性。两性霉素B和氟康唑是用于隐球菌感染治疗的一线药物,而长期广泛用药引起新生隐球菌对氟康唑的耐药率逐年升高,患者临床治疗失败率居高不下。为进一步加深对新生隐球菌的认识,本文结合国内外流行病学报道及相关研究,从感染现状、生物学特征、诊治方法和耐药性等方面进行综述,以期为新生隐球菌性脑膜炎的临床诊治提供参考。     

氯喹与氟康唑联合对新生隐球菌的体外药敏实验

目的研究氯喹与氟康唑体外联合应用对隐球菌生长作用的影响。方法参考M27-A方案,检测10μmol/L,100μmol/L与1 000μmol/L 3种浓度氯喹与氟康唑联合后对20株菌株的氟康唑对隐球菌最小抑菌浓度与最小杀菌浓度的变化。结果与10μmol/L氯喹组相比,100μmol/L以上浓度的氯喹组可以显著降低氟康唑对隐球菌的M IC与MFC。结论氯喹在体外可以提高氟康唑抗隐球菌的作用,与氟康唑具有协同抗隐球菌的作用。     

小鼠烟曲霉角膜炎的实验研究

目的 比较伊曲康唑和氟康唑对烟曲霉的体外抗菌活性,观察伊曲康唑对小鼠烟曲霉角膜炎的治疗作用.方法 通过角膜基质注射法建立烟曲霉角膜炎小鼠模型.造模后观察角膜病变,取角膜病变处分泌物做真菌镜检、真菌培养以证实造模成功.用药基法检测伊曲康唑和氟康唑对烟曲霉的最低抑菌浓度( MIC)和最低杀菌浓度(MFC).对烟曲霉角膜炎小鼠给予伊曲康唑治疗,治疗结束行临床评分、炎性评分、菌落形成单位测定以评价疗效.结果 伊曲康唑对烟曲霉的MIC和MFC分别为6.25 μg/mL、12.5 μg/mL;氟康唑对烟曲霉的MIC和MFC分别为500 μg/mL、1 000 μg/mL.伊曲康唑治疗组临床评分、炎性评分和测定的菌落数较对照组均明显减少(P＜0.05).结论 伊曲康唑对烟曲霉的体外抗菌活性优于氟康唑,并且对烟曲霉性角膜炎有明显疗效.     

大鼠脑隐球菌感染模型建立及MRI评估

目的 建立大鼠脑感染隐球菌模型并探讨MRI评估的影像学表现。方法 运用立体定位技术给30只SD大鼠尾状核注射浓度为1×10⁶ CFU/mL的新生隐球菌菌悬液10μL,分别于大鼠建模后第14、21、28天进行T1WI、T2WI序列扫描,MRI动态监测大鼠脑内感染情况,病理解剖鼠脑并观察组织形态。结果 1×10⁶ CFU/mL浓度的新生隐球菌菌悬液建立大鼠隐球菌感染模型成功率为73.33%,隐球菌肉芽肿60%,隐球菌性脑膜脑炎13.33%;无明显异常改变20%。大鼠脑隐球菌肉芽肿MRI表现为尾状核类圆形或结节样异常信号影,T1WI低信号T2WI高信号;脑膜脑炎MRI表现为脑膜、室管膜明显线样异常信号。结论 1×10⁶ CFU/mL浓度的新生隐球菌菌悬液建立大鼠脑感染隐球菌模型,耗时短且接种成功率较高。MRI表现与病理结果高度契合,可为人脑隐球菌感染诊断及效果评估提供良好的研究模型。     

播散性隐球菌病1例及其实验研究

目的 播散性隐球菌病1例临床及实验研究.方法 患者男,72岁,红皮病1年2个月,口服醋酸泼尼松治疗,双下肢出现结节、溃烂6个月.皮损组织病理、皮损组织真菌培养、尿素酶试验、PCR扩增测序比对明确诊断,同时做胸部及脑部CT.结果 皮损组织病理显示为感染肉芽肿改变,可见大量圆形和椭圆形酵母细胞.皮损组织真菌培养可见酵母样菌落生长,菌株尿素酶试验阳性,ITS区测序比对鉴定为新生隐球菌grubii变种.血清隐球菌荚膜多糖抗原乳胶凝集试验阳性(++++).胸部CT显示左下肺后基底段空洞性病灶.依据临床及实验室检查确诊为由新生隐球菌grubii变种引起的 播散性隐球菌病.给予患者静滴氟康唑400 mg/d治疗2周,之后改口服300 mg/d治疗,3个月后结节性皮损全部消退,胸片显示左肺陈旧性病变,血清隐球菌荚膜多糖抗原乳胶凝集试验阳性(++).治疗15个月后,血清隐球菌荚膜多糖抗原乳胶凝集试验仍阳性(++).结论 对该病例的临床和实验室研究为临床明确诊断和治疗提供了依据,确定菌种需要进行分子生物学研究.     

山苍子油对小鼠系统性新生隐球菌感染的实验研究

目的研究山苍子油治疗小鼠系统性新生隐球菌感染的疗效。方法建立小鼠系统性新生隐球菌感染模型,观察给药后小鼠的中位生存时间,检测小鼠肾脏及肺菌落形成单位计数。结果山苍子油不仅能够显著延长感染小鼠的中位生存时间,提高其生存率,而且可显著增加感染小鼠肾脏及肺菌落清除率。结论山苍子油对系统性新生隐球菌感染小鼠具有治疗作用。     

《中药大辞典》记载的抗真菌中药体外药效再评价

目的对《中药大辞典》中记载有抗真菌药理作用的127种中药醇提物进行体外抗深部感染真菌(白念珠菌、新生隐球菌、烟曲霉)的研究。方法采用75%乙醇超声提取法对127种中药进行统一提取,参考CLSI微量液基稀释法M27-A3和M38-A2方案进行抗白念珠菌、新生隐球菌、烟曲霉的最低抑菌浓度(MIC)测定,并进一步考察其抗菌谱及抑制菌丝作用。结果在2mg/mL浓度下,仅博落回等17种中药、月季花等34种中药、黄柏等5种中药分别对白念珠菌、新生隐球菌、烟曲霉有抑制作用,其中博落回和粉萆薢的抗菌谱广;在4mg/mL浓度下,127种中药中仅粉萆薢和藜芦能完全抑制菌丝生长,最低浓度分别为200μg/mL和500μg/mL。结论首次用统一标准对《中药大辞典》中记载的抗真菌中药进行体外活性筛选,并对其药效进行再评价,为新型抗真菌药物开发提供理论依据和参考。     

In vitro susceptibility to antifungal agents of environmental Cryptococcus spp. isolated in the city of Ribeirão Preto, São Paulo, Brazil

Infections by Cryptococcus strains other than C. neoformans have been detected in immunocompromised patients. Of these strains, three are considered human pathogens: C. albidus, C. laurenttii, and C. uniguttulatus. This study deals with the in vitro susceptibility of Cryptococcus to drugs such as amphotericin B, itraconazole, fluconazole, and 5-fluorocytosine. Environmental Cryptococcus isolates (50) distributed as follows: C. neoformans var. neoformans (16), C. albidus (17), C. laurentii (14), and C. uniguttulatus (3) were evaluated by the micro and macrodilution techniques, according to EUCAST and NCCLS recommendations, respectively. Considering both methodologies the respective minimal inhibitory concentrations (MIC) were 0.125 and 2 microg/ml for amphotericin B, 0.06 and 8 microg/ml for itraconazole, and 0.5 and more than 64 microg/ml for fluconazole and 5-fluorocytosine. Agreement percentages for the two methodologies were 100% for amphotericin B and fluconazole for all the strains tested. For itraconazole, the agreement percentage was 81.3% in the C. neoformans strain and 100% for all the others. All species had a agreement percentage of 94.1 to 100% when susceptibility to 5-fluorocytosine was tested. It is concluded that environmental isolates of C. neoformans var. neoformans, C. albidus, C. laurentii, and C. uniguttulatus may show high MICs against certain drugs, suggesting in vitro primary resistance to the antifungals tested.     

Carbon analogs of antifungal dioxane-triazole derivatives: synthesis and in vitro activities

A new series of triazole compounds possessing a carbon atom in place of a sulfur atom were efficiently synthesized and their in vitro antifungal activities were investigated. The carbon analogs showed excellent in vitro activity against Candida, Cryptococcus, and Aspergillus species. The MICs of compound 1c against C. albicans ATCC24433, C. neoformans TIMM1855, and A. fumigatus ATCC26430 were 0.016, 0.016, and 0.125 microg/mL, respectively (MICs of fluconazole: 0.5, >4, and >4 microg/mL; MICs of itraconazole: 0.125, 0.25, and 0.25 microg/mL).     

Carboxylic acid and phosphate ester derivatives of fluconazole: synthesis and antifungal activities

Two classes of fluconazole derivatives, (a) carboxylic acid esters and (b) fatty alcohol and carbohydrate phosphate esters, were synthesized and evaluated in vitro against Cryptococcus neoformans, Candida albicans, and Aspergillus niger. All carboxylic acid ester derivatives of fluconazole (1a-l), such as O-2-bromooctanoylfluconazole (1g, MIC=111 microg/mL) and O-11-bromoundecanoylfluconazole (1j, MIC=198 microg/mL), exhibited higher antifungal activity than fluconazole (MIC > or = 4444 microg/mL) against C. albicans ATCC 14053 in SDB medium. Several fatty alcohol phosphate triester derivatives of fluconazole, such as 2a, 2b, 2f, 2g, and 2h, exhibited enhanced antifungal activities against C. albicans and/or A. niger compared to fluconazole in SDB medium. For example, 2-cyanoethyl-omega-undecylenyl fluconazole phosphate (2b) with MIC value of 122 microg/mL had at least 36 times greater antifungal activity than fluconazole against C. albicans in SDB medium. Methyl-undecanyl fluconazole phosphate (2f) with a MIC value of 190 microg/mL was at least 3-fold more potent than fluconazole against A. niger ATCC 16404. All compounds had higher estimated lipophilicity and dermal permeability than those for fluconazole. These results demonstrate the potential of these antifungal agents for further development as sustained-release topical antifungal chemotherapeutic agents.     

Molecular typing and antifungal susceptibility of clinical sequential isolates of Cryptococcus neoformans from Sao Paulo State, Brazil

The antifungal susceptibility profiles and the genetic variability of 83 sequential clinical isolates of Cryptococcus neoformans, including four Cryptococcus gattii isolates, obtained from 38 Sao Paulo AIDS patients with cryptococcal meningitis were assessed by electrophoretic karyotyping and random amplified polymorphic DNA (RAPD) analysis. The majority of the Cryptococcus neoformans isolates were highly susceptible to amphotericin B and fluconazole. Twenty percent of the minimum inhibitory concentration values for amphotericin B varied from 0.5 to 1 micro g mL(-1). For fluconazole, 22% occurred in the range 8-16 mug mL(-1). Sequential isolates from nine patients showed a trend towards lower susceptibility to fluconazole, flucytosine, itraconazole and amphotericin B. The results of molecular typing by electrophoretic karyotyping and RAPD analysis showed the presence of 22 electrophoretic karyotypes (EK) and 15 RAPD profiles that were highly correlated. Our results provided evidence for the occurrence of genetic changes in some strains associated with microevolution during the course of infection. We also observed both microevolution and simultaneous coinfection with two distinct Cryptococcus neoformans strains in one patient. In some patients, we found changed EK- and RAPD patterns in association with increased MIC values.     

In vitro antifungal susceptibility of clinical isolates of Cryptococcus neoformans var. neoformans and C. neoformans var. gattii

One of the differences observed between the two varieties of Cryptococcus neoformansis the greater difficulty to achieve an adequate therapeutical response in patients affected by C. neoformans var. gattii, an observation that has been validated in vitro only rarely. The aim of this work was to study the susceptibility patterns of 35 Colombian clinical isolates of C. neoformans, 20 of which belonged to the var. neoformans and 15 to the var. gattii. The minimal inhibitory concentration (MIC) was determined by broth microdilution, according to a modification of the methodology proposed by the National Committee for Clinical Laboratory Standards (NCCLS), using the breakpoints recently suggested by Nguyen et al. (Antimicrob Agents Chemother 1998; 42: 471-472). The antifungals tested were amphotericin B, fluconazole and itraconazole. Most of the isolates were susceptible to the three antimycotics tested regardless of the variety. Resistance to amphotericin B (MIC=2 microg/ml) was documented in two (10%) C. neoformans var. neoformans isolates; additionally, five (33%) C. neoformans var. gattii isolates felt in the category of fluconazole susceptible but dose dependent (MIC 16 microg/ml). In general, all C. neoformans var. gattii isolates proved susceptible only to the higher concentrations of the antifungals tested. For amphotericin B, seven (47%) isolates of this variety had MICs of 1 microg/ml, for fluconazole there were seven (47%) with MICs of 8 microg/ml and in the case of itraconazole, 10 isolates (66%) had MICs > 0.03 microg/ml. The data showed that although these isolates would be classified as susceptible, they actually require greater concentrations of the antifungals to be inhibited. This finding may well correlate both with the difficulty to attain therapeutic success in patients affected with C. neoformans var. gattii and with the need for more prolonged treatment courses in such cases.     

In vitro resistance to fluconazole and itraconazole in clinical isolates of Candida spp and Cryptococcus neoformans

An in vitro susceptibility testing of 181 strains of six species of Candida and 21 strains of Cryptococcus neoformans was carried out in order to investigate the resistance to new antifungal drugs. We have studied clinical isolates from 200 different patients of Hospital del Mar (Barcelona) and Hospital La Inmaculada (Almería). An agar diffusion method (NeoSensitabs, Rosco, Taastrup, Denmark), was employed with fluconazole, itraconazole, and reference drugs amphotericin B, flucytosine, tioconazole and ketoconazole. A high level of susceptibility was found for amphotericin B in C. neoformans strains while 19% of them were resistant to flucytosine. All the strains of C. neoformans and Candida guilliermondii were susceptible to the new azoles derivatives and also Candida parapsilosis and Candida albicans had a great susceptibility to this antifungals. A greater level of resistance was found for Candida krusei, Candida tropicalis and Candida glabrata to fluconazole, itraconazole and ketoconazole, but resistance to fluconazole and itraconazole is not always linked because ten resistant strains for fluconazole were susceptible to itraconazole, and two other resistant to itraconazole were susceptible to fluconazole.     

Combined effect of furanone fluconazole and amphotericin B against biofilms formed from Cryptococcus neoformans

It is of interest to document the combined effect of furanone fluconazole and amphotericin B against the biofilm formed by Cryptococcus neoformans. The MIC values of amphotericine B and Fluconazole were observed as 20µg/ml and 60µg/ml, respectively. The MIC for the Combination (Amphotericin B/ Fluconazole) was found to be at (15/20) µg/ml drug concentration. Thus, data shows the combined effect of furanone fluconazole and amphotericine B derivative against C. neoformans.     

ATB FUNGUS2法在念珠菌属和新生隐球菌抗真菌药敏试验中应用的评价

目的评价ATBFUNGUS2半固体培养基法在测定念珠菌属和新生隐球菌对4种常用抗真菌药物敏感性中的应用价值。方法利用CLSIM27．A2微量液基稀释法和ATBFUNGUS2法同时测定131株念珠菌和20株新生隐球菌对两性霉素B（AmB）、氟康唑（FLC）、氟胞嘧啶（5-Fc）和伊曲康唑（ITC）的敏感性。结果①两种方法对于AmB、5-FC、FLC和ITC的一致性分别为98％、89．4％、78．8％和78．1％;②所有受试菌株中两种方法的一致性为80％,但ATBFUNGUS2法将2／5株M27-A2法检查为FLC耐药的白念珠菌判断为敏感或剂量依赖,将8／10株M27-A2法检查为FLC剂量依赖的白念珠菌判断为敏感或耐药。③ATBFUNGUS2法中AmB的MIC值判读范围偏高,以致于实际工作中不能读出准确的值。结论ATBFUNGUS2半固体培养基法在测定念珠菌属和新生隐球菌对4种常用抗真菌药物的敏感性时不失为简单、快速而且重复性好的方法。     

In vitro activity of the synthetic lipopeptide PAL-Lys-Lys-NH(2) alone and in combination with antifungal agents against clinical isolates of Cryptococcus neoformans

The in vitro activity of the lipopeptide PAL-Lys-Lys-NH(2) (PAL), alone or combined with either fluconazole (FLU) or amphotericin B (AMB), was investigated against 14 Cryptococcus neoformans isolates. PAL MICs ranged from 1.0 to 4.0 microg/ml. Fungicidal activity was observed. Synergy, defined as a fractional inhibitory concentration (FIC) index of < or =0.5, was observed in 21.4% of PAL/AMB interactions. Antagonism (FIC index>4) was never observed. The broad antifungal activity and the positive interactions with AMB suggest that PAL can represent a promising candidate in infections due to C. neoformans.