Distribution and drug susceptibilities of Candida species causing candidemia from a medical center in central Taiwan

Invasive fungal infections have increased significantly in the past few decades because of the increase in high-risk populations. To investigate the distribution and drug susceptibilities of such infections, we analyzed all 152 Candida isolates causing candidemia from 2004 to 2006 at the China Medical University Hospital, a medical center in central Taiwan. Candida albicans was the most common species, accounting for 52.6 % of the isolates, followed by C. tropicalis (19.7 %), C. parapsilosis (14.5 %), C. glabrata (8.6 %), C. guilliermondii (3.9 %), and C. pelliculosa (0.7 %). All isolates were susceptible to amphotericin B, anidulafungin, micafungin, and voriconazole according to minimum inhibitory concentrations (MICs) after a 24-h incubation; 0.7 %, 6.6 %, and 7.9 % of isolates were resistant to amphotericin B, fluconazole, and voriconazole, respectively, after 48-h incubation. Both C. albicans and C. parapsilosis had high degrees of agreement for azoles between 24- and 48-h incubation periods, whereas C. glabrata (38.5–46.2 %) and C. tropicalis (56.7–63.3 %) did not. The majority of the isolates with high azole MICs displayed a trailing growth phenotype. Hence, the MICs of different drugs after 24-h incubation may be considered for prognosis of candidemia.     

Prospective multicenter study of the epidemiology, molecular identification, and antifungal susceptibility of Candida parapsilosis, Candida orthopsilosis, and Candida metapsilosis isolated from patients with candidemia

A 13-month prospective multicenter study including 44 hospitals was carried out to evaluate the epidemiology of Candida parapsilosis complex candidemia in Spain. Susceptibility to amphotericin B, flucytosine, fluconazole, itraconazole, voriconazole, posaconazole, anidulafungin, caspofungin, and micafungin was tested by the microdilution colorimetric method. A total of 364 C. parapsilosis complex isolates were identified by molecular methods: C. parapsilosis (90.7%), Candida orthopsilosis (8.2%), and Candida metapsilosis (1.1%). Most candidemias (C. parapsilosis, 76.4%; C. orthopsilosis, 70.0%; C. metapsilosis, 100%) were observed in adults. No C. orthopsilosis or C. metapsilosis candidemias occurred in neonates. C. parapsilosis was most frequent in adult intensive care unit (28.8%), surgery (20.9%), and internal medicine (19.7%) departments; and C. orthopsilosis was most frequent in hematology (28.6%), pediatrics (12.0%), and neonatology (11.5%) departments. The geographic distribution of C. orthopsilosis and C. metapsilosis was not uniform. According to CLSI clinical breakpoints, all C. orthopsilosis and C. metapsilosis isolates were susceptible to the nine agents tested. Resistance (MICs > 1 mg/liter) was observed only in C. parapsilosis: amphotericin B, posaconazole, itraconazole, and caspofungin (0.3% each), anidulafungin (1.9%), and micafungin (2.5%). Applying the new species-specific fluconazole and echinocandin breakpoints, the rates of resistance to fluconazole for C. parapsilosis and C. orthopsilosis increased to 4.8% and 0.3%, respectively; conversely, for C. parapsilosis they shifted from 1.9 to 0.6% (anidulafungin) and from 2.5 to 0.6% (micafungin). Our study confirms the different prevalence of C. parapsilosis complex candidemia among age groups: neither C. orthopsilosis nor C. metapsilosis was isolated from neonates; interestingly, C. metapsilosis was isolated only from adults and the elderly. The disparity in antifungal susceptibility among species could be important for therapy.     

念珠菌感染的菌种分布及耐药性监测

目的了解本地区2004年~2005年念珠菌感染的菌种分布和耐药性情况。方法收集本地区数家医疗机构两年间临床分离的念珠菌1037株,采用科玛嘉显色培养基及梅里埃API 20C AUX方法进行念珠菌菌种的分离鉴定,药敏试验采用NCCLS推荐的M44-P方案检测念珠菌对氟康唑和沃尔康唑耐药性,对伊曲康唑、酮康唑、5-氟胞嘧啶和两性霉素B的敏感性采用ROSCOS药片法。结果1037株念珠菌中以白色念珠菌为主,检出583株(56.3%),其他依次为热带念珠菌243株(23.6%),光滑念珠菌75株(7.2%),近平滑念珠菌43株(4.2%)葡萄牙念珠菌31株(2.9%)克柔念珠菌29株(2.7%),其他念珠菌32株(3,1%)。念珠菌对伊曲康唑、酮康唑、氟康唑、5-氟胞嘧啶和两性霉素B的耐药率分别为26.5%、22.5%、10.7%、2.5%和1.0%。结论本地区念珠菌感染以白念珠菌为主,对伊曲康唑、酮康唑和氟康唑耐药性较高,对5-氟胞嘧啶和两性霉素B敏感性较高。     

获得性免疫缺陷综合征患者白假丝酵母分离株基因型及耐药性分析

目的研究获得性免疫缺陷综合征(AIDS)患者白假丝酵母分离株的基因型及耐药性。方法对分离自上海市公共卫生中心AIDS住院患者的40株白假丝酵母,应用微卫星核心序列引物M13进行聚合酶链反应(PCR)指纹分型。用微量稀释法分析白假丝酵母抗真菌药物敏感性。结果PCR指纹分型将所有白假丝酵母分离株分为A、B、C、D 4种基因型,其中A型14株(35.0%),B型16株(40.0%),C型9株(22.5%),D型1株(2.5%)。白假丝酵母对抗真菌药物的耐药率为:两性霉素B 2.5%,氟康唑22.5%,伊曲康唑15.0%,氟胞嘧啶20.0%,;不同基因型白假丝酵母菌株间耐药性差异无统计学意义。结论上海市AIDS住院患者分离的白假丝酵母主要由3种克隆组成,但无明显优势流行株。     

获得性免疫缺陷综合征患者白假丝酵母分离株基因型及耐药性分析

目的研究获得性免疫缺陷综合征（AIDS）患者白假丝酵母分离株的基因型及耐药性。方法对分离自上海市公共卫生中心AIDS住院患者的40株白假丝酵母,应用微卫星核心序列引物M13进行聚合酶链反应（PCR）指纹分型。用微量稀释法分析白假丝酵母抗真菌药物敏感性。结果PCR指纹分型将所有白假丝酵母分离株分为A、B、C、D 4种基因型,其中A型14株（35.0%）,B型16株（40.0%）,C型9株（22.5%）,D型1株（2.5%）。白假丝酵母对抗真菌药物的耐药率为：两性霉素B 2.5%,氟康唑22.5%,伊曲康唑15.0%,氟胞嘧啶20.0%,;不同基因型白假丝酵母菌株间耐药性差异无统计学意义。结论上海市AIDS住院患者分离的白假丝酵母主要由3种克隆组成,但无明显优势流行株。     

Prevalence and susceptibility profile of Candida metapsilosis and Candida orthopsilosis: results from population-based surveillance of candidemia in Spain

We describe the prevalences and susceptibility profiles of two recently described species, Candida metapsilosis and Candida orthopsilosis, related to Candida parapsilosis in candidemia. The prevalences of these species (1.7% for C. metapsilosis and 1.4% for C. orthopsilosis) are significant. Differences observed in their susceptibility profiles could have therapeutic importance.     

临床分离念珠菌对5种常用抗真菌药物的体外敏感试验结果分析

目的　了解临床分离的念珠菌对氟康唑、两性霉素B、氟胞嘧啶、伊曲康唑及酮康唑体外敏感性。方法　采用SensititreYeastOne试验板以微量稀释法测定上述 5种抗真菌药物对临床分离的 10 8株念珠菌最低抑菌浓度 (MIC)。结果　 10 8株念珠菌中达到氟康唑、伊曲康唑、氟胞嘧啶耐药标准的分别有 8株 (7.4%)、15株(13.9%)、2株 (1.9%) ,念珠菌属MIC值分布种间差异较大。白色念珠菌对 5种药物的MIC90 值最低 ,6 0株白色念珠菌中仅 2株耐氟康唑 ,3株耐伊曲康唑 ,对氟胞嘧啶无耐药株 ;光滑念珠菌对氟康唑、伊曲康唑、酮康唑的MIC值分布呈高值 ,10株光滑念珠菌中 4株耐氟康唑 ,3株剂量依赖性敏感 ,7株耐伊曲康唑 ,且吡咯类之间有交叉耐药。其他菌株 ,除季也蒙念珠菌对伊曲康唑有一定的耐药 (2 /6 )外 ,对 5种抗真菌药物的MIC分布均较低。结论　不同念珠菌对常用抗真菌药物敏感性存在差异 ,准确分离鉴定和药敏试验 ,对于指导临床合理选药有重要意义。     

临床分离念珠菌对5种常用抗真菌药物的体外敏感试验结果分析

目的了解临床分离的念珠菌对氟康唑、两性霉素B、氟胞嘧啶、伊曲康唑及酮康唑体外敏感性.方法采用Sensititre YeastOne试验板以微量稀释法测定上述5种抗真菌药物对临床分离的108株念珠菌最低抑菌浓度(MIC).结果 108株念珠菌中达到氟康唑、伊曲康唑、氟胞嘧啶耐药标准的分别有8株(7.4%)、15株(13.9%)、2株(1.9%),念珠菌属MIC值分布种间差异较大.白色念珠菌对5种药物的MIC90值最低,60株白色念珠菌中仅2株耐氟康唑,3株耐伊曲康唑,对氟胞嘧啶无耐药株;光滑念珠菌对氟康唑、伊曲康唑、酮康唑的MIC值分布呈高值,10株光滑念珠菌中4株耐氟康唑,3株剂量依赖性敏感,7株耐伊曲康唑,且吡咯类之间有交叉耐药.其他菌株,除季也蒙念珠菌对伊曲康唑有一定的耐药(2/6)外,对5种抗真菌药物的MIC分布均较低.结论不同念珠菌对常用抗真菌药物敏感性存在差异,准确分离鉴定和药敏试验,对于指导临床合理选药有重要意义.     

微量稀释法检测念珠菌对抗真菌药物敏感性的两种观察结果方法的比较

目的 用微量稀释法检测念珠菌对抗真菌药物敏感性,比较肉眼观察和体视显微镜观察结果的优缺点及一致性.方法 参考美国临床实验室标准化委员会(CISI)的微量稀释法M27-A3,检测203株念珠菌对4种唑类药物(咪康唑、酮康唑、益康唑、联苯芐唑)及4种非唑类药物(制霉菌素、利拉萘酯、萘替芬、特比萘芬)的体外敏感性,并同时用肉...     

143株念珠菌菌种分布及对5种抗真菌药物的敏感性分析

目的分析临床标本中念珠菌属的菌种分布及对常用抗真菌药物的敏感性,为临床合理用药提供依据。方法总结分析昆明市延安医院2005—2009年念珠菌属的菌种分布及其对5种常用抗真菌药物的敏感性。药敏试验采用ATB-Fungus-3微量稀释法。结果在2005—2009年分离的共143株念珠菌中,白念珠菌占39.2%(56/143),非白念珠菌占60.8%(87/143),非白念珠菌中,以光滑念珠菌24.5%(35/143)、热带念珠菌7.7%(11/143)和近平滑念珠菌5.6%(8/143)较为常见。143株念珠菌对氟胞嘧啶、两性霉素B、氟康唑、伊曲康唑和伏立康唑的总敏感率分别为86.0%、100%、90.9%、69.9%和93.5%,56株白念珠菌对上述5种抗真菌药的敏感率分别为91.1%、100%、96.4%、82.1%和96.3%,87株非白念珠菌的敏感率分别为82.8%、100%、87.4%、62.1%和92.0%。结论白念珠菌仍是目前念珠菌感染较常见的菌种,但非白念珠菌已显著增加;白念珠菌对常用抗真菌药仍有较高的敏感性,非白念珠菌的耐药性则高于白念珠菌。临床在治疗念珠菌感染时应结合菌种鉴定及药敏试验结果合理选择抗真菌药物。     

白假丝酵母临床分离株基因分型与药敏分析

目的分析上海交通大学医学院附属瑞金医院白假丝酵母的基因分型情况以及不同基因型白假丝酵母的药敏结果。方法采用聚合酶链反应(PCR)扩增白假丝酵母25S核糖体DNA基因的内含子区,可转座Ⅰ型内含子插入片段的数目及大小的不同使得扩增产物不同,根据产物片段大小和数目分型。采用微量稀释法分析白假丝酵母抗真菌药物敏感性。结果171株白假丝酵母分为3型:A型93株,B型47株,C型31株。B型、C型白假丝酵母对唑类抗真菌药物的耐药率显著高于A型菌株,对氟胞嘧啶的耐药率低于A型菌株。结论白假丝酵母的PCR分型方法简便、快速、重复性好、特异性强;不同型别的白假丝酵母耐药谱有差异,对治疗中抗真菌药物的选择有一定的指导意义。     

白假丝酵母临床分离株基因分型与药敏分析

目的分析上海交通大学医学院附属瑞金医院白假丝酵母的基因分型情况以及不同基因型白假丝酵母的药敏结果。方法采用聚合酶链反应（PCR）扩增白假丝酵母25S核糖体DNA基因的内含子区,可转座Ⅰ型内含子插入片段的数目及大小的不同使得扩增产物不同,根据产物片段大小和数目分型。采用微量稀释法分析白假丝酵母抗真菌药物敏感性。结果171株白假丝酵母分为3型：A型93株,B型47株,C型31株。B型、C型白假丝酵母对唑类抗真菌药物的耐药率显著高于A型菌株,对氟胞嘧啶的耐药率低于A型菌株。结论白假丝酵母的PCR分型方法简便、快速、重复性好、特异性强;不同型别的白假丝酵母耐药谱有差异,对治疗中抗真菌药物的选择有一定的指导意义。     

In vitro susceptibility of Candida dubliniensis to current and new antifungal agents

BACKGROUND: Candida dubliniensis is a recently described Candida species closely related to Candida albicans, which has been associated with oral candidiasis in HIV-infected patients. Fluconazole-resistant strains of C. dubliniensis are easily obtained in vitro and this fact could be a complication if this resistance develops during treatment with this drug. METHODS: In the present study, the in vitro antifungal susceptibilities of 36 C. dubliniensis clinical isolates and culture strains to current and new antifungal agents, such as amphotericin B (AMB), amphotericin B lipid complex (ABLC), amphotericin B colloidal dispersion (ABCD), 5-fluorocytosine (5FC), fluconazole (FLC), itraconazole (ITC), ketoconazole (KTC), liposomal amphoteri- cin B (LAMB), liposomal nystatin (LNYT), LY303366 (LY), SCH56592 (SCH), and voriconazole (VRC), were determined according to the National Committee for Clinical Laboratory Standards M27-A broth microdilution method for yeasts. RESULTS: Most isolates of C. dubliniensis were susceptible to both new and current antifungal drugs, with 75.9% isolates susceptible to KTC, 86.2% to FLC and to ITC, and approximately 100% to the other antifungal agents tested. The cross-resistance phenotypes are detailed. Four isolates were resistant (MIC > or =64 microg/ml) to FLC. These 4 isolates were also resistant to KTC, and 3 of them were also resistant to ITC (MIC > or =1 microg/ml for both agents). However, these isolates were highly susceptible to 5FC and all polyene formulations (AMB, ABLC, ABCD, LAMB, and LNYT), triazole (SCH and VRC) and echinocandin (LY) antifungal agents. CONCLUSION: The new liposomal and lipidic formulations of AMB, LNYT, and the new triazoles and echinocandins may provide new alternatives to FLC for the treatment of infections by C. dubliniensis.     

Reduced Candida glabrata susceptibility secondary to an FKS1 mutation developed during candidemia treatment

We describe a case of recurring Candida glabrata infection in a 68-year-old African-American female on caspofungin therapy. The initial isolate was susceptible, but isolates recovered during following relapses were not. All isolates were clonal, and high-MIC strains contained a mutation in the highly conserved hot spot 1 region of Fks1p.     

Utility of real-time antifungal susceptibility testing for fluconazole in the treatment of candidemia

Our study prospectively examined the use of real-time antifungal susceptibility testing among 119 patients with candidemia at a large tertiary university medical center over a 1-year period. Susceptibility results to fluconazole were reported to physicians a mean of 5.1 days after the initial positive blood culture for Candida. Physicians believed that receiving antifungal susceptibility testing results was helpful and not infrequently altered therapy on the basis of results. Outcomes, including mortality and resolution of infection, among 20 (17%) patients with fluconazole-resistant and fluconazole-susceptible dose-dependent isolates were relatively poor compared to those among patients with fluconazole-susceptible isolates, but probably reflect severity of illness. Routine susceptibility testing as an adjunct to the treatment of candidemia has significant potential and warrants further study.     

National surveillance of species distribution in blood isolates of Candida species in Japan and their susceptibility to six antifungal agents including voriconazole and micafungin

OBJECTIVES: The aim of this study was to evaluate species distribution and antifungal susceptibility of Candida blood isolates in Japan. METHODS: In a 1 year surveillance programme, 535 Candida blood isolates were collected. Identification of species was followed by examination with the broth microdilution method, as described in NCCLS M27-A2, of antifungal susceptibility to six agents, including voriconazole and micafungin, with readings after 24 and 48 h of incubation. RESULTS: The overall species distribution was: 41% Candida albicans, 23% Candida parapsilosis, 18% Candida glabrata, 12% Candida tropicalis and 2% Candida krusei. The concentrations of fluconazole necessary to inhibit 90% of the isolates (MIC(90)) at 24/48 h were 0.25/1 mg/L for C. albicans, 0.5/2 mg/L for C. parapsilosis, 4/32 mg/L for C. glabrata and 4/>128 mg/L for C. tropicalis. Percentages of fluconazole resistance were 1.8% for C. albicans, 0.8% for C. parapsilosis, 5.2% for C. glabrata and 3.2% for C. tropicalis, taking the tendency of trailing growth of C. tropicalis into account. MIC(90) of voriconazole was 0.5 mg/L, although 35% of isolates less susceptible (>/=16 mg/L) to fluconazole showed resistance (>/=2 mg/L). Micafungin was very active against all species (MIC(90), 0.03 mg/L) except for C. parapsilosis (MIC(90), 2 mg/L). CONCLUSIONS: These data suggest that, in Japan, the species distribution of Candida bloodstream infections and the fluconazole resistance rate are similar to those reported previously in North America and Europe. Voriconazole and micafungin appear to have strong in vitro activity against Candida blood isolates, although continuing surveillance and further clinical research are needed.     

Epidemiological study of Candida infections in blood: susceptibilities of Candida spp. to antifungal agents, and clinical features associated with the candidemia

The purpose of this study was to evaluate the susceptibility to antifungal agents of Candida spp. isolated from blood samples from patients in our hospital, located in Osaka, Japan. We also examined the clinical background of these patients. We analyzed fungi isolated from clinical blood samples obtained in our hospital over a period of 10 years (1993 to 2002). Antifungal susceptibility testing was carried out for six agents, using the National Committee of Clinical Laboratory Standards (NCCLS) M-27-A2 method. The clinical backgrounds were reviewed using the medical records of 125 patients who were diagnosed as having candidemia. The major fungi isolated were Candida parapsilosis (39.2%) and C. albicans (30.1%), and both were sensitive to fluconazole. One strain of C. glabrata and six strains of C. krusei were resistant to fluconazole, and they constituted 4.4% of all Candida spp. isolated. With the exception of C. parapsilosis, most fungi were susceptible to micafungin, although there is no universally agreed breakpoint for this drug. Analysis of the patients' clinical backgrounds revealed that the major underlying disease was cancer (46.4% excluding hematological malignancies). C. krusei was detected almost exclusively in patients with hematological malignancies. Indwelling venous catheters had been responsible for infection in 93.6% of the infected patients. The clinical outcomes of the 125 patients were favorable in 52% and poor in 48%, and subsequent removal of the indwelling catheters was effective in about half of the patients in whom this was done, with good prognosis. To prevent mycosis and its complications, indwelling catheters should be avoided as much as possible. Attention must be paid to the possibility that resistant isolates of Candida spp. can be selected as a result of the use of antifungal agents.