格特隐球菌在河北地区引起1例脑膜炎的临床与实验研究

目的报道1例我国河北地区由格特隐球菌引起的脑膜炎,并对该菌进行试验研究。方法将分离自患者脑脊液中的隐球菌分别接种于Chromagar显色培养基和刀豆氨酸-甘氨酸-溴麝香草酚蓝(CGB)培养基35℃培养,使用API 20C AUX、全自动微生物鉴定仪Vitek 2 Compact、生物梅里埃基质辅助激光解析电离飞行时间质谱分析(MALDI-TOF MS)、r DNA ITS和IGS序列分析等方法对该菌进行菌种鉴定,并使用ATB FUNGUS 3进行抗真菌药敏试验。结果该菌在显色培养基上35℃培养48 h后为白色略带粉色菌落,在CGB培养基35℃培养5 d后使CGB培养基由黄色变为蓝色。API 20C AUX、Vitek 2 Compact和MALDI-TOF MS的鉴定结果均为新生隐球菌,r DNA ITS和IGS序列分析均提示该菌为格特隐球菌。5-氟胞嘧啶、两性霉素B、氟康唑、伊曲康唑、伏立康唑对该菌的最小抑菌浓度分别是≤4μg/m L、≤0.5μg/m L、≤1μg/m L、≤0.125μg/m L、≤0.06μg/m L。结论 CGB培养基、r DNA ITS和IGS序列分析能够区分新生隐球菌和格特隐球菌,应重视格特隐球菌的分离鉴定。     

国内首例皮瘤丝孢酵母真菌血症分离株的表型及rDNA序列鉴定

目的通过对1例“脂膜炎”患者外周血分离株的表型及分子生物学鉴定,报道国内首例皮瘤丝孢酵母菌血症。方法采集患者的血及鼻咽结节组织标本通过真菌培养获得分离株,经沙氏培养基、马铃薯培养基、科玛嘉念珠菌显色培养后形态学观察及API 20C AUX系统鉴定,最后经PCR扩增rDNA基因测序证实。采用CLSI制定的M27-A2微量稀释法对病原菌株进行7种药物的体外药敏试验。结果分离株通过表型和分子生物学鉴定为“皮瘤丝孢酵母”。药敏结果显示菌株对两性霉素B耐药,氟康唑、伏立康唑、伊曲康唑、5-氟胞嘧啶敏感。卡泊芬净的抑菌浓度较低,而米卡芬净的抑菌浓度相对较高。患者因多种并发症死亡。结论皮瘤丝孢酵母引起的真菌血症为我国首例报道。API 20C AUX酵母鉴定系统可作为鉴定皮瘤丝孢酵母快速而简便的方法。通过分子生物学DNA序列检测分析能鉴定皮瘤丝孢酵母。     

男性尿道炎和包皮龟头炎致病真菌的分布与药敏分析

目的了解男性念珠菌性尿道炎和包皮龟头炎的菌群分布及体外抗真菌药敏试验情况。方法菌株分离均来自复旦大学附属华山医院皮肤性病门诊临床症状轻重不一、真菌直接镜检阳性的61例患者。用科玛嘉念珠菌显色培养基及API 20C AUX鉴定系统进行菌种鉴定;采用CLSIM27-A2肉汤微量稀释法对61株临床分离念珠菌作了氟康唑、两性霉素B、氟胞嘧啶、伊曲康唑、伏立康唑、特比萘芬6种抗真菌药物敏感性测定。结果对培养阳性的61例菌株,通过科玛嘉念珠菌显色培养基及API 20C AUX鉴定系统作菌种鉴定,白念珠菌52例（85.2%）,近平滑念珠菌3例,光滑念珠菌2例,热带念珠菌2例,季也蒙念珠菌1例,克柔念珠菌1例。对52株白念珠菌的药敏试验显示氟康唑98.1%敏感,1.9%剂量依赖性敏感;氟胞嘧啶96.2%敏感,3.8%耐药;伊曲康唑44.2%敏感,40.5%剂量依赖性敏感,15.3%耐药;伏立康唑84.6%敏感,15.4%耐药;两性霉素B全部敏感;特比萘芬的MIC范围为1-64μg/ml,MIC50和MIC90皆为64μg/ml。结论在男性念珠菌性尿道炎和包皮龟头炎中,白念珠菌仍是第一位致病菌,体外药敏试验显示氟康唑、伏立康唑、氟胞嘧啶、两性霉素B对男性念珠菌性尿道炎均有较好的敏感性。     

Sensititre YeastOne显色药敏板与微量肉汤稀释法检测阿萨希毛孢子菌体外药物敏感性比较研究CSCD

目的以CLSI微量肉汤稀释法为参考方法,探讨商品化显色药敏板(Sensititre YeastOne)检测阿萨希毛孢子菌体外药物敏感性的临床应用价值。方法分别用微量肉汤稀释法和Sensititre YeastOne同时检测62株阿萨希毛孢子菌对临床常用7种抗真菌药物的体外敏感性,MIC值读取时间分别为24h和48h。结果微量肉汤稀释法结果显示卡泊芬净和米卡芬净对阿萨希毛孢子菌无体外活性,二者MIC90均为16μg/mL;唑类药物对阿萨希毛孢子菌体外活性较好,培养24h MIC90分别为氟康唑8μg/mL、伏立康唑0.125μg/mL、伊曲康唑0.5μg/mL;4.8%(3/62)阿萨希毛孢子菌对两性霉素B有高MIC值(4μg/mL);经24h培养,Sensititre YeastOne与微量肉汤稀释法检测阿萨希毛孢子菌对7种抗真菌药物的体外MIC一致率(essential agreement,EA)分别为氟康唑93.5%,伏立康唑98.4%,伊曲康唑98.4%,两性霉素B 98.4%,5-氟胞嘧啶88.7%,卡泊芬净100%,米卡芬净100%;培养48h后,二者检测两性霉素B和5-氟胞嘧啶MIC一致率有所下降,分别为83.9%和67.7%;对微量肉汤稀释法而言,培养时间对两性霉素B和5-氟胞嘧啶MIC值影响较大,24h和48hMIC一致率分别为69.4%和53.2%,对Sensititre YeastOne,MIC值明显受培养时间影响的药物仅见于5-氟胞嘧啶,24h和48h MIC一致率为11.3%,其余药物不同MIC读取时间一致率非常好。结论唑类药物对阿萨希毛孢子菌体外抗菌活性较好,Sensititre YeastOne和微量肉汤稀释法检测阿萨希毛孢子菌体外MIC值一致率较高,用于临床阿萨希毛孢子菌体外药物敏感性检测具有一定的实用价值。     

胶红酵母致真菌血症1例：临床及实验研究

目的报道1例由胶红酵母感染引起的真菌血症。方法通过对患者血培养分离致病菌,并作API 20C AUX及DNA序列测定鉴定菌种,采用抗真菌药敏纸片法对菌株进行体外药敏试验。结果患者,女性,38岁,因反复出现右乳肿块5个月行右乳肿块穿刺活检术,术后高热,发生于每日下午至夜间。2次查血真菌培养均为阳性,经菌落观察、API 20C AUX鉴定及基因测序,鉴定为胶红酵母。体外药敏试验显示对两性霉素B敏感,对伊曲康唑、氟康唑、伏立康唑耐药。未予治疗,24d后自愈。结论胶红酵母菌血症在国内罕见报道,其菌株毒力相对较低,在免疫功能正常患者中,部分病例可自愈。     

Sensititre YeastOne显色药敏板与微量肉汤稀释法检测阿萨希毛孢子菌体外药物敏感性比较研究

目的以CLSI微量肉汤稀释法为参考方法,探讨商品化显色药敏板(Sensititre YeastOne)检测阿萨希毛孢子菌体外药物敏感性的临床应用价值。方法分别用微量肉汤稀释法和Sensititre YeastOne同时检测62株阿萨希毛孢子菌对临床常用7种抗真菌药物的体外敏感性,MIC值读取时间分别为24h和48h。结果微量肉汤稀释法结果显示卡泊芬净和米卡芬净对阿萨希毛孢子菌无体外活性,二者MIC90均为16μg/mL;唑类药物对阿萨希毛孢子菌体外活性较好,培养24h MIC90分别为氟康唑8μg/mL、伏立康唑0.125μg/mL、伊曲康唑0.5μg/mL;4.8%(3/62)阿萨希毛孢子菌对两性霉素B有高MIC值(4μg/mL);经24h培养,Sensititre YeastOne与微量肉汤稀释法检测阿萨希毛孢子菌对7种抗真菌药物的体外MIC一致率(essential agreement,EA)分别为氟康唑93.5%,伏立康唑98.4%,伊曲康唑98.4%,两性霉素B 98.4%,5-氟胞嘧啶88.7%,卡泊芬净100%,米卡芬净100%;培养48h后,二者检测两性霉素B和5-氟胞嘧啶MIC一致率有所下降,分别为83.9%和67.7%;对微量肉汤稀释法而言,培养时间对两性霉素B和5-氟胞嘧啶MIC值影响较大,24h和48hMIC一致率分别为69.4%和53.2%,对Sensititre YeastOne,MIC值明显受培养时间影响的药物仅见于5-氟胞嘧啶,24h和48h MIC一致率为11.3%,其余药物不同MIC读取时间一致率非常好。结论唑类药物对阿萨希毛孢子菌体外抗菌活性较好,Sensititre YeastOne和微量肉汤稀释法检测阿萨希毛孢子菌体外MIC值一致率较高,用于临床阿萨希毛孢子菌体外药物敏感性检测具有一定的实用价值。     

289株VVC致病菌的菌种分布和对9种抗真菌药物敏感性

外阴阴道念珠菌病（vulvovaginal candidiasis,VVC）是女性的常见病。本研究收集了2018年1月-12月苏州地区VVC患者分离的289株念珠菌进行了病原学鉴定和包括棘白菌素类、新三唑类药物在内的9种抗真菌药物体外敏感性分析。本文采用核糖体RNA的D1/D2基因进行念珠菌菌种鉴定。参照M27-A3方法检测其对9种抗真菌药物（包括棘白菌素类及新三唑类药物）的体外敏感性。结果表明,289株VVC念珠菌菌株中,白念珠菌259株、光滑念珠菌14株、克柔念珠菌10株、热带念珠菌4株、近平滑念珠菌2株。259株VVC白念珠菌对棘白菌素类体外敏感性好,对米卡芬净敏感性高于另外两种棘白菌素类;对两性霉素B、5-氟胞嘧啶、氟康唑敏感性好;但对伊曲康唑、伏立康唑敏感性差;对泊沙康唑敏感性好。光滑念珠菌株和克柔念珠菌分离株对卡泊芬净敏感性差,但对米卡芬净、阿尼芬净敏感性好;光滑念珠菌株对两性霉素B、5-氟胞嘧啶体外敏感性好,对伊曲康唑敏感性差,对泊沙康唑敏感性好;伏立康唑对光滑念珠菌分离株MIC₅₀/₉₀为0.5/1μg/mL;克柔念珠菌对伊曲康唑、伏立康唑50%耐药;4株热带念珠菌对伊曲康唑50%耐药,对卡泊芬净、氟康唑、伏立康唑100%耐药,对其余5种抗真菌药物敏感。近平滑念珠菌对9种抗真菌药物均敏感。白念珠菌仍为苏州地区VVC的主要病原菌,其次是光滑念珠菌和克柔念珠菌,它们对临床常用药物伊曲康唑、伏立康唑、卡泊芬净敏感性差。研究结果提示对VVC病人常规进行分泌物培养、菌种鉴定,对苏州地区临床医生制定VVC治疗方案具有重要参考价值。尽管棘白菌素类、两性霉素B、5-氟胞嘧啶、新三唑类药物尚未应用到VVC的临床治疗中,但是这些药物对VVC病原体总体敏感性较好,未来有望成为氟康唑、咪唑类药物治疗失败患者的新选择。     

85株皮肤癣菌感染的病原菌分析及标准化体外药物敏感性研究

目的分析深圳地区教学医院门诊皮肤癣菌感染的病原菌特点,测定7种抗真菌药物对85株皮肤癣菌的体外抗真菌活性。方法收集疑诊为皮肤癣菌感染的患者的皮屑(或甲板刮屑、毛发)进行KOH直接镜检和培养。并通过测定皮肤癣菌临床分离菌株的核糖体DNA内转录间隔区(ITS)区序列鉴定菌种。参考CLSI M38-A2方案,测定7种抗真菌药物对85株鉴定为皮肤癣菌的临床分离菌株的体外抗真菌活性。结果 161例疑诊为皮肤癣菌感染的患者中KOH直接镜检皮肤癣菌的阳性率为67.7%,真菌培养皮肤癣菌的阳性率为52.8%。菌种鉴定结果为红色毛癣菌68例、犬小孢子菌7例、石膏样小孢子菌3例、趾间毛癣菌5例、紫色毛癣菌1例、断发毛癣菌1例。体外药敏试验显示特比萘芬(GM MIC,0.032μg·mL~(-1), MIC范围, 0.001～0.125μg·mL~(-1))对6种皮肤癣菌表现出良好的体外抗真菌活性,而伏立康唑(GM MIC, 0.041μg·mL~(-1), MIC范围, 0.032～0.125μg·mL~(-1))在唑类药物中的体外MIC值相对较低。结论本研究中皮肤癣菌感染的致病菌以红色毛癣菌为主。标准化药敏试验证实特比萘芬和伏立康唑对分离的皮肤癣菌具有较强体外抗菌活力,适用于本地区皮肤癣菌感染的治疗。     

常见皮肤癣菌体外药物敏感试验的研究

目的比较液基稀释法和纸片扩散法对临床常见皮肤癣菌的体外药物敏感性。方法应用Rosco纸片扩散法和微量液基法（参考美国国家实验室标准委员会NCCLS推荐的M38-P方案修改方案）测定临床分离的40株皮肤癣菌（包括红色毛癣菌、须癣毛癣菌、犬小孢子菌及絮状表皮癣菌）对两性霉素B、伊曲康唑、氟康唑和特比萘芬的体外药物敏感性。结果应用Rosco纸片扩散法,大部分菌株在7—9d时可读到清晰的结果。Rosco纸片扩散法和微量液基法结果中,特比萘芬、伊曲康唑和两性霉素B一致性较好,氟康唑较差。结论Rosco纸片扩散法操作简单,可选择用于皮肤癣菌对某些抗真菌药的药敏试验。     

应用CLSI M38-A2方案测定须癣毛癣菌对抗真菌药物敏感性

目的:对我国代表地区须癣毛癣菌临床分离株作抗真菌药物敏感性测定,进一步验证CLSI的M38-A2方案.方法:选取我国南北方8个省市地区经表型和分子生物学鉴定的趾间型毛癣菌38株和苯海姆节皮菌6株,采用M38-A2方案测定氟康唑、伊曲康唑、伏立康唑、特比萘芬、灰黄霉素、联苯苄唑、环吡酮胺和阿莫罗芬等8种常见抗真菌药物的最小抑菌浓度(minimal inhibitory concentration,MIC).结果:氟康唑、伊曲康唑、伏立康唑、特比萘芬、灰黄霉素、联苯苄唑、环吡酮胺和阿莫罗芬对趾间型毛癣菌株的MIC值(μg/mL)范围分别为0.25-32、0.0312-1、0.0156-0.0625、0.000937-0.00781、0.0625-1、0.0312-2、1-2、0.00781-0.0625;对苯海姆节皮菌株的MIC值(μg/mL)范围分别为≥64、2、0.25-0.5、0.000937-0.00381、1、2-4、1-2、0.0312-0.0625.不同抗真菌药物对趾间型毛癣菌及苯海姆节皮菌的药敏有明显差别(P<0.001);趾间型毛癣菌和苯海姆节皮菌对伊曲康唑、灰黄霉素、环吡酮胺、伏立康唑和氟康唑的药敏差异有统计学意义,对特比萘芬、阿莫罗芬和联苯苄唑的药敏差异无统计学意义.结论:趾间型毛癣菌和苯海姆节皮菌之间对伊曲康唑、灰黄霉素、环吡酮胺、伏立康唑和氟康唑的药敏有明显差异.M38-A2方案有较好的重复性和稳定性,适合用来体外测定须癣毛癣菌对抗真菌药物的敏感性.     

In vitro antifungal activities of anidulafungin and micafungin, licensed agents and the investigational triazole posaconazole as determined by NCCLS methods for 12,052 fungal isolates: review of the literature

The echinocandins anidulafungin and micafungin and the triazole posaconazole are currently undergoing phase III clinical trials. Caspofungin and voriconazole have recently been licensed for the treatment of aspergillosis (both agents), other less common mould (voriconazole) and candidal (caspofungin) infections. This review summarizes the published in vitro data obtained by NCCLS or NCCLS modified methods on the in vitro fungistatic and fungicidal activities of these five agents for yeasts and moulds in comparison to the established agents, amphotericin B, fluconazole, itraconazole, and flucytosine. Among the yeasts, the echinocandins have less activity for Candida parapsilosis and Candida guilliermondii, no activity for Cryptococcus neoformans and Trichosporon spp., but good fungistatic and fungicidal activity in vivo and in vitro for most of the other Candida spp.; this fungicidal activity has been reported by minimum fungicidal concentrations (MFCs) or time kill curve results. The new triazoles exhibit good fungistatic activity (but not fungicidal) for most Candida spp., C. neoformans, and Trichosporon spp. For the Aspergillus spp. evaluated, the echinocandins have similar or better fungistatic activity than those of amphotericin B and the triazoles, but fungicidal activity has been demonstrated only with amphotericin B and the triazoles, with the exception of fluconazole. Most studies showed posaconazole and voriconazole minimum inhibitory concentrations (MICs) ranging from 0.25 to 8 microg/ml for non-solani Fusarium spp., while MIC and minimum effective concentration (MEC) endpoints of the echinocandins were >8 microg/ml. The fungistatic activity of the triazoles is also superior to that of the echinocandins for most of the dimorphic fungi and the Zygomycetes. However, micafungin has activity for the mould phase of most dimorphic fungi, but not for the parasitic or yeast phase of Paracoccidioides brasiliensis. The echinocandins appear to have variable and species dependent fungistatic activity for the dematiaceous fungi, but all agents have poor or no activity against most isolates of Scedosporium prolificans. Only amphotericin B exhibit good fungistatic activity against the Zygomycetes. The combination of caspofungin with some triazoles, amphotericin B or liposomal amphotericin B has been synergistic in vitro, in animal models and in patients. Breakpoints are not available for any mould and antifungal agent combination. In vitro/in vivo correlations should aid in the interpretation of these results, but standard testing conditions are needed for the echinocandins, especially for mould testing, to obtain reliable results.     

Antifungal Activity of Antifungal Drugs,as Well as Drug Combinations Against <Emphasis Type="Italic">Exophiala dermatitidis</Emphasis>

To evaluate the in vitro efficacy of common antifungal drugs, as well as the interactions of caspofungin with voriconazole, amphotericin B, or itraconazole against the pathogenic black yeast Exophiala dermatitidis from China, the minimal inhibitory concentrations (MICs) of terbinafine, voriconazole, itraconazole, amphotericin B, fluconazole, and caspofungin against 16 strains of E. dermatitidis were determined by using CLSI broth microdilution method (M38-A2). The minimal fungicidal concentrations (MFCs) were also determined. Additionally, the interactions of caspofungin with voriconazole, amphotericin B, itraconazole or fluconazole, that of terbinafine with itraconazole, or that of fluconazole with amphotericin B were assessed by using the checkerboard technique. The fractional inhibitory concentration index (FICI) was used to categorize drug interactions as following, synergy, FICI ≤ 0.5; indifference, FICI > 0.5 and ≤4.0; or antagonism, FICI > 4.0. The MIC ranges of terbinafine, voriconazole, itraconazole, amphotericin B, fluconazole, and caspofungin against E. dermatitidis were 0.06–0.125 mg/l, 0.25–1.0 mg/l, 1.0–2.0 mg/l, 1.0–2.0 mg/l, 16–64 mg/l, and 32–64 mg/l, respectively. The in vitro interactions of caspofungin with voriconazole, amphotericin B, and itraconazole showed synergic effect against 10/16(62.5%), 15/16(93.75%), and 16/16(100%) isolates, while that of caspofungin with fluconazole showed indifference. Besides, the interaction of terbinafine with itraconazole as well as that of fluconazole with amphotericin B showed indifference. Terbinafine, voriconazole, itraconazole, and amphotericin B have good activity against E. dermatitidis. The combinations of caspofungin with voriconazole, amphotericin B or itraconazole present synergic activity against E. dermatitidis. These results provide the basis for novel options in treating various E. dermatitidis infections.     

Evaluation of Antifungal Susceptibility Testing with Microdilution and Etest Methods of <Emphasis Type="Italic">Candida</Emphasis> Blood Isolates

Candida species that show an increasing number of clinical and/or microbiological resistance to several antifungals and are the most common agents of invasive fungal infections. The aim of this study was to investigate the in vitro susceptibility of Candida blood isolates to antifungal agents (amphotericin B, fluconazole, itraconazole, and voriconazole) by comparative use of the CLSI reference microdilution method and Etest. Four hundred Candida blood isolates (215 Candida albicans, 185 non-albicans Candida strains) were included in the study. The broth microdilution test was performed according to the CLSI M27 A2 document. Etest was carried out according to the manufacturer’s instructions. The MIC results obtained with reference microdilution were compared with those obtained with the Etest by using percent and categorical agreements. According to MIK₉₀ values, voriconazole was the most active and itraconazole was the least active drug in vitro against all Candida species. Other than voriconazole, statistically significant differences were found when the susceptibility of Candida albicans and non-albicans Candida spp. to amphotericin B, fluconazole, and itraconazole were compared. These antifungal agents were found to be more active to C. albicans. Among the non-albicans Candida species, the lowest MIC values were obtained for Candida parapsilosis isolates. When the standard method was compared with Etest, the total agreement was higher for C. albicans than for non-albicans species, especially for fluconazole and voriconazole. In view of the findings, it was concluded that itraconazole showed the lowest activity against all Candida species. Etest could be an alternative method in assessing the in vitro antifungal susceptibility of Candida spp., but it is more convenient to use the microdilution method for studying in vitro susceptibility of non-albicans species, in particular for those possessing high MIC values against azoles.     

Correlation between broth microdilution and disk diffusion methods for antifungal susceptibility testing of caspofungin, voriconazole, amphotericin B, itraconazole and fluconazole against Candida glabrata

Candida glabrata is one of the most frequent organisms isolated from superficial and invasive fungal infections, after Candida albicans. This organism also exhibits intrinsically low susceptibility to azole antifungals and treatment often fails. The microdilution method is not very practical for use in routine susceptibility testing in the clinical laboratory, thus necessitating the use of other methods. In this study, we compared the in vitro activity of five antifungal agents in three different groups (echinocandin, polyene and azole) against 50 C. glabrata isolates by broth microdilution and disk diffusion methods recommended by Clinical Laboratory Standards Institute CLSI M27-A3 and CLSI M44-A, respectively. All the isolates were susceptible to amphotericin B (100%) and 98% of the isolates were susceptible to caspofungin by the broth microdilution method. Within the azole group drugs, voriconazole was the most active followed by fluconazole and itraconazole in vitro. The highest rate of resistance was obtained against itraconazole with a high number of isolates defined as susceptible-dose dependent or resistant. Although the disk diffusion method is easy to use in clinical laboratories, it shows very poor agreement with the reference method for fluconazole and itraconazole against C. glabrata (8% and 14%, respectively).     

Antifungal susceptibility of bloodstream yeasts isolated at a public children's hospital in Brazil: comparison of the Etest and the AFST-EUCAST microdilution method

This study compared the minimum inhibitory concentration (MIC) results from the proposed standard methods of the Antifungal Susceptibility Testing Subcommittee of the European Committee on Antibiotic Susceptibility Testing (AFST-EUCAST) with the commercial system Etest(R) in the evaluation of susceptibility to flucytosine, fluconazole, itraconazole, voriconazole, and amphotericin B of 136 Candida spp. isolated from the blood of hospitalized children. The results presented a greater agreement among Etest(R) MICs +/-2 log2 dilutions of AFST-EUCAST for fluconazole (98.1% and 96.3%) and voriconazole (100% and 100%) for Candida albicans and Candida parapsilosis. For Candida glabrata, the agreement was greater only for fluconazole (81.8%) and voriconazole (100%). For amphotericin B, the agreement between the methods was low for all species. The agreement percentage among the Etest(R) and AFST-EUCAST susceptibility profiles was high according to the MIC breakpoints recommended by the M27-A2 protocol for the majority of the yeasts, except for fluconazole and itraconazole against Candida tropicalis and for itraconazole against C. glabrata and Candida krusei. According to both methodologies, a great number of Candida spp. isolates showed an in vitro susceptibility to all evaluated antifungal agents. Overall, both procedures can be reliable techniques for susceptibility tests of yeasts, but the assessment of interlaboratory agreement and correlation of MICs by different methods with in vivo response are of great importance.     

In vitro activities of voriconazole, fluconazole, itraconazole and amphotericin B against non Candida albicans yeast isolates

Antifungal susceptibility testing was performed on 197 yeast isolates from the BCCM/IHEM biomedical fungi and yeasts collection (Belgian Co-ordinated Collections of Micro-organisms / IPH-Mycology) to study the in vitro activity of voriconazole against fluconazole, itraconazole and amphotericin B. MICs of the four antifungal agents were determined by an adapted NCCLS M27-A microdilution reference method. MIC readings were visually and spectrophotometrically determined. Optical density data were used for calculation of the MIC endpoints. For amphotericin B, the MIC endpoint was defined as the minimal antifungal concentration that exerts 90% inhibition, compared to the control growth. The azoles endpoints were determined at 50% inhibition of growth. The MIC distribution of voriconazole susceptibilities showed that 193 isolates had a MIC < or = 2 microg/ml and 185 a MIC < or = 1 microg/ml. Cross-tabulation of voriconazole, fluconazole, and itraconazole MICs indicated that voriconazole MICs raised with fluconazole and itraconazole MICs. The in vitro data obtained in this study suggest that voriconazole may also be effective treating yeast infection in patients infected with fluconazole or itraconazole resistant isolates.     

In vitro antifungal susceptibility of clinical isolates of Candida spp. obtained from patients with different predisposing factors to candidosis

The increase in the number of infections caused by Candida species and the consequent use of antifungal agents favours an increase of resistant isolates. The aim of this study was to evaluate the antifungal susceptibility of Candida spp. isolates from patients with different systemic predisposing factors to candidosis. Seventy-nine Candida spp. isolates were assayed for in vitro susceptibility to amphotericin B, fluconazole, 5-flucytosine and itraconazole using the technique proposed by the Clinical and Laboratory Standards Institute (CLSI). Four C. albicans, one C. guilliermondii, four C. parapsilosis and two C. tropicalis isolates were resistant to amphotericin B. Only two isolate was resistant to itraconazole. All the isolates tested were susceptible to fluconazole and flucytosine. It could be concluded that the most efficient drugs against the Candida isolates studied were fluconazole and flucytosine and that all of the antifungal agents used in this study were effective against the Candida spp. isolates tested.     

In vitro antifungal activities of voriconazole and reference agents as determined by NCCLS methods: Review of the literature

Voriconazole (Vfend™) is a new triazole that currently is undergoing phase III clinical trials. This review summarizes the published data obtained by NCCLS methods on the in vitro antifungal activity of voriconazole in comparison to itraconazole, amphotericin B, fluconazole, ketoconazole and flucytosine. Voriconazole had fungistatic activity against most yeasts and yeastlike species (minimum inhibitory concentrations [MICs] <2 μg/ml) that was similar or superior to those of fluconazole, amphotericin B, and itraconazole. Against Candida glabrata and C. krusei, voriconazole MIC ranges were 0.03 to 8 and 0.01 to >4 μg/ml, respectively. For four of the six Aspergillus spp. evaluated, voriconazole MICs (< 0.03 to 2 μg/ml) were lower than amphotericin B (0.25 to 4 μg/ml) and similar to itraconazole MICs. Voriconazole fungistatic activity against Fusarium spp. has been variable. Against F. oxysporum and solani, most studies showed MICs ranging from 0.25 to 8 μg/ml. Voriconazole had excellent fungistatic activity against five of the six species of dimorphic fungi evaluated (MIC₉₀s < 1.0 μg/ml). The exception was Sporothrix schenckii (MIC₉₀s and geometric mean MICs ≥ 8 μg/ml). Only amphotericin B had good fungistatic activity against the Zygomycetes species (voriconazole MICs ranged from 2 to >32 μg/ml). Voriconazole showed excellent in vitro activity (MICs < 0.03 to 1.0 μg/ml) against most of the 50 species of dematiaceous fungi tested, but the activity of all the agents was poor against most isolates of Scedosporium prolificans and Phaeoacremonium parasiticum (Phialophora parasitica). Voriconazole had fungicidal activity against most Aspergillus spp., B. dermatitidis, and some dematiaceous fungi. In vitro/in vivo correlations should aid in the interpretation of these results. This revised version was published online in June 2006 with corrections to the Cover Date.