共生菌和致病性口腔念珠菌耐药性的比较

目的:评价和比较共生菌、致病性口腔念珠菌感染的种类及对3种抗真菌药氟康唑、5-氟胞嘧啶和伊曲康唑的药物敏感性。方法:收集临床菌株,经YBCTestKit鉴定其念珠菌种类;根据NCCLS的M27-A2标准方案,测定3组(共生菌、口腔念珠菌病、头颈部放化疗患者合并口腔念珠菌感染)菌株对3种抗真菌药物的最低抑菌浓度。结果:3组临床分离株对5-氟胞嘧啶全部敏感,3组对氟康唑和伊曲康唑均有一定的耐药比例,放化疗组的非白色念珠菌比例及耐药比例明显高于正常共生菌组和口腔念珠菌病组。结论:共生菌和致病性口腔念珠菌均对氟康唑和伊曲康唑存在一定的耐药比例和交叉耐药比例。     

致病性口腔白色念珠菌耐药株和药物敏感株的ITS基因型比较

目的:探讨致病性口腔念珠菌ITS1-ITS2区域进化中变异的序列是否与接受放化疗相关,是否与菌株对抗真菌药物的敏感性相关.方法:收集两组(头颈部肿瘤放化疗患者合并念珠菌感染组和单纯口腔念珠菌感染组)临床菌株,依据NCCLS的M27-A2标准方案测定两组菌株对四种抗真菌药物的最低抑菌浓度;提取菌株的DNA,PCR扩增ITS1-ITS2区域,比较两组ITS1-ITS2序列的差异并比较药物敏感株和耐药株该区域核苷酸碱基序列的差异.结果:全部菌株对5-氟胞嘧啶敏感,92.1%对两性霉素B敏感,放化疗组和单纯白念感染组对氟康唑的耐药比例分别为26.7%和8.7%,对伊曲康唑的耐药比例分别为40%和13%;菌株ITS1-ITS2序列的差异与分组和药物敏感性无明显相关.结论:致病性口腔念珠菌ITS1-ITS2区域进化中变异的序列与是否接受放化疗无明显相关,与菌株对抗真菌药物的敏感性无明显相关.     

头颈部放化疗后口腔假丝酵母菌耐药性分析及抗真菌中药筛选

目的 研究头颈部放化疗患者口腔假丝酵母菌感染菌株的种类及耐药性,并依据美国国家临床实验室标准协会（NCCLS）的M27-A2标准方案筛选抗真菌中药。方法 采集头颈部放化疗患者口腔假丝酵母菌感染的临床分离菌株20株,经YBC Test Kit鉴定假丝酵母菌种类;依据NCCLS的M27-A2标准方案测定其对5-氟胞嘧啶、氟康唑、伊曲康唑、6种中药提取物（蒺藜、金银花、蒲公英、绿茶、松树皮、红三叶草提取物）及7种中药有效成分（苦参碱、苦豆碱、大黄素、甘草酸、白芍总苷、黄芩苷、盐酸小蘖碱）的药物敏感性。结果 20株放化疗患者口腔假丝酵母菌感染菌株中非白假丝酵母菌5株,对5-氟胞嘧啶全部敏感,对氟康唑和伊曲康唑的耐药比例分别为25%和40%;白芍总苷和盐酸小蘖碱具有抗假丝酵母菌活性。结论 头颈部放化疗患者口腔假丝酵母菌感染菌株中非白假丝酵母菌比例及对氟康唑和伊曲康唑的耐药比例较高;白芍总苷和盐酸小蘖碱是有临床应用前景的抗口腔假丝酵母菌药物;依据NCCLS的M27-A2标准方案筛选抗真菌中药是一种准确有效的方法。     

HIV感染患者口腔念珠菌的培养鉴定及耐药性研究

目的：研究HIV感染患者口腔念珠菌感染的菌株种类和耐药情况,比较CHROMagar显色培养基（CHROMagar）和API 20C AUX酵母菌鉴定系统（API）在HIV感染者口腔念珠菌鉴别中的应用,指导临床抗真菌药物的使用。方法：6株念珠菌标准菌株和17例HIV感染合并口腔念珠菌病患者舌背白色刮取物,分别接种于沙氏培养基和CHROMagar,37℃48h后取沙氏培养基上生长物作API 20C AUX鉴定和耐药性检测。结果：白色念珠菌8例,热带念珠菌4例,近平滑念珠菌4例,白色念珠菌和克柔念珠菌混合感染1例。念珠菌对特比萘芬耐药,对氟康唑、酮康唑、眯康唑、克霉唑中度敏感,对制霉菌素、伊曲康唑、两性霉素B、氟胞嘧啶高度敏感。API 20C AUX、CHROMagar在鉴定白色念珠菌上无显著性差异,API20CAUX鉴定非白色念珠菌准确率高于CHROMagar,但CHROMagar可鉴别混合菌种感染。结论：HIV感染患者口腔念珠菌以非白色念珠菌居多（52．9％）,分型初筛可用CHROMagar,准确分型需用API20CAUX鉴定,两种方法互有裨益。临床用药建议选择制霉菌素、伊曲康唑、两性霉素B、氟胞嘧啶中的两种任意综合治疗。     

HIV感染者口腔念珠菌的耐药性研究

目的 :调查人类免疫缺陷病毒 (HIV)感染者口腔念珠菌感染的菌株耐药情况 ,指导临床抗真菌药的使用。方法 :取 17例HIV感染者舌背白色培养物中鉴别出的念珠菌 :白色念珠菌 8例 ,热带念珠菌 4例 ,近平滑念珠菌 4例 ,白色念珠菌和克柔念珠菌混合感染 1例 ,用Neo Sensitab纸片扩散法检测其对 9种抗真菌药物的耐药性。结果 :检测出的念珠菌对特比萘芬耐药 ,对氟康唑、酮康唑、咪康唑、克霉唑中度敏感 ,对制霉菌素、伊曲康唑、两性霉素B、氟胞嘧啶高度敏感。结论 :对HIV感染者口腔念珠菌感染临床用药建议选择制霉菌素、伊曲康唑、两性霉素B、氟胞嘧啶中的任意两种配伍治疗。     

萎缩糜烂型口腔扁平苔藓患者不同基因型白色念珠菌的药敏研究

目的:对萎缩糜烂型口腔扁平苔藓不同基因型白色念珠菌进行药物敏感性研究,为临床有效治疗萎缩糜烂型口腔扁平苔藓白色念珠菌感染提供依据。方法:采用聚合酶链反应(PCR)对101株萎缩糜烂型口腔扁平苔藓白色念珠菌进行基因分型,然后采用微量稀释法测定白色念珠菌不同基因型对4种临床常用抗真菌药物的敏感性。采用SPSS16.0软件包对数据进行χ2检验。结果:101株白色念珠菌中,A型39株,B型17株,C型45株。A型对5-氟胞嘧啶耐药率显著高于B、C型(P<0.05);B型对氟康唑耐药率显著高于A型(P<0.05);C型对伊曲康唑耐药率显著高于A型(P<0.05);B、C型均未出现制霉菌素耐药株,A、B、C型对制霉菌素的耐药率无显著性差异(P>0.05)。结论:萎缩糜烂型口腔扁平苔藓白色念珠菌不同基因型对抗真菌药物的耐药性有差异,治疗时应根据基因分型和药敏试验结果合理选用抗真菌药物。治疗萎缩糜烂型口腔扁平苔藓伴发白色念珠菌感染时,制霉菌素的临床价值应该引起充分重视。     

口腔白念珠菌基因型分析及临床意义

目的 研究不同口腔黏膜病白念珠菌分离株的基因型特点。方法 采用计算机系统辅助随机扩增多态性DNA(RAPD)分析，对健康人和黏膜病患者口腔的38株念珠菌菌株进行基因分型。结果 38株菌株中36株被鉴定为白念菌，其余2株为热带念珠菌。白念菌RAPD分析共出现21种RAPD带型。扁平苔藓组与口腔念珠菌病组间白念致病菌RAPD指纹图无明显相似性。结论 不同基因型白念菌的定植可能与口腔黏膜病的种类有关。     

口腔念珠菌病患者口内菌株的检出和药敏性观察

目的通过对健康人和口腔念珠菌病患者口内假丝酵母菌（即念珠菌）株的检测和药物敏感性试验,探讨假丝酵母菌的种类及药敏性,并结合制霉菌素局部疗效的观察,初步探讨最小抑菌浓度（MIC）值与临床疗效的关系,为临床用药提供参考。方法选择61例口腔念珠菌病患者为试验组,43例健康自愿者为对照组,含漱法收集口腔假丝酵母菌标本,采用CHROMagar假丝酵母菌显色培养基对其进行分离鉴定,然后采用NCCLSM27- A微量稀释法测定假丝酵母菌分离株对制霉菌素、酮康唑和氟康唑的MIC值。试验组中选择31例进行制霉菌素治疗,1周后观察临床疗效,并与患者的MIC值作比较。结果①试验组和对照组假丝酵母菌检出率分别为78.69%和30.23%,其中白色假丝酵母菌分别占80.70%和92.31%。②白色假丝酵母菌对氟康唑和酮康唑的MIC值均数间无统计学差异（P>0.05）,但唑类药物的MIC值小于制霉菌素。③白色假丝酵母菌对氟康唑、酮康唑和制霉菌素的敏感率分别为95.65%、80.43%和89.13%,少数菌株存在耐药现象。④制霉菌素局部治疗口腔念珠菌病有效率为87.10%,存在少数MIC值与临床疗效结果不一的病例。结论目前口腔假丝酵母菌感染患者口内菌株的耐药现象并不突出,白色假丝酵母菌对氟康唑、酮康唑、制霉菌素的敏感率均较高;酮康唑和氟康唑MIC值较小,提示临床上用制霉菌素治疗疗效欠佳时可换用唑类药物。MIC值与临床疗效存在一定相关性,但MIC值高低与临床疗效并非完全一致。     

口腔黏膜病

小剂量皮质激素在控制天疱疮复发中的应用；HIV感染者及艾滋病患者口腔白色念珠菌毒性的体外研究；扁平苔藓患者血小板聚集和血液流变学研究；致病性口腔白色念球菌耐药株和药物敏感株的ITS基因型比较。     

口腔白色念珠菌基因型与扁平苔藓的关系

目的:分析口腔白色念珠菌基因型与口腔扁平苔藓的关系,白色念珠菌致病菌与共生菌基因型的相关性,为临床制定有效防治措施提供依据。方法:采用随机扩增多态性DNA(RAPD)基因分型方法,对46株口腔念珠菌行基因型观察。46株菌分为以下3组,自健康志愿者口腔中所取的9株共生菌为N组;自口腔单纯白色念珠菌感染者口腔中所取的21株致病菌为OC组;口腔扁平苔藓伴发的16株致病菌为LP组。结果:46株念珠菌中,40株被鉴定为白色念珠菌,基因分型显示不同念珠菌有各自独特基因型。OC组与N组白色念珠菌基因型相似度较高。LP组白色念珠菌基因型无集中趋势,与N组比较存在显著差异(P<0.001)。同是致病菌的白色念珠菌,组与组间基因型也存在显著性差别(P<0.001)。结论:(1)RAPD基因分型可将念珠菌区分至菌种水平,也可深入分辨“同种异型”。(2)口腔单纯白色念珠菌感染可能由共生菌菌群失调引起,即由内源性感染引起。(3)扁平苔藓伴发白色念珠菌基因型无集中趋势,提示扁平苔藓伴发白色念珠菌存在外源性感染的可能。(4)不同口腔黏膜病所伴发的白色念珠菌基因型不同。     

Oral Candida isolates in patients undergoing radiotherapy for head and neck cancer: prevalence, azole susceptibility profiles and response to antifungal treatment

Oral pseudomembranous candidiasis and mucositis were assessed in 39 patients receiving a total dose of 39-70 Gy radiotherapy for head and neck cancer. Mucositis was scored using the Radiation Therapy Oncology Group criteria, and oral candidiasis was diagnosed on the basis of clinical evaluation and quantitative laboratory findings. Radiation-induced mucositis was observed in 9/39 patients. Only 3/39 patients discontinued radiotherapy due to acute severe mucosal effects. Candidiasis (colony-forming units 35 to > or = 60/lesion) associated with mucositis was diagnosed in 30/39 patients: the most frequent aetiology of the infection was Candida albicans (n = 23), followed by Candida glabrata (n = 3), Candida krusei (n = 2), Candida tropicalis (n = 1) and Candida kefyr (n = 1). Patients with confirmed oral pseudomembranous candidiasis were treated with either fluconazole 200 mg/day or itraconazole 200 mg/day for 2 weeks. Clinical improvement and concomitant negative Candida cultures (mycologic cure) were the criteria determining a response to antifungal treatment. Etest revealed very low voriconazole MICs (0.004-0.125 microg/ml) for all isolates, and fluconazole resistance for eight C. albicans strains (MIC > 64 microg/ml) and for the C. krusei isolates (MIC > 32 microg/ml). The same strains showed itraconazole susceptibility dose dependence (MIC 0.5 microg/ml). Despite the itraconazole susceptible dose dependent MIC readings, all patients with oral pseudomembranous candidiasis caused by these strains responded to antifungal treatment with 200 mg/day itraconazole. Oral mycologic surveillance of patients undergoing radiotherapy for head and neck malignancies and susceptibility testing of isolates may be indicated in cases with mucositis-associated confirmed oral pseudomembranous candidiasis to ensure prompt administration of targeted antifungal treatment. On the basis of the low MIC values found, clinical evaluation of voriconazole is indicated for management of oral pseudomembranous candidiasis refractory to other azoles.     

In vitro susceptibility of oral Candida to seven antifungal agents

The in vitro susceptibility of 618 Candida isolates to fluconazole, itraconazole, voriconazole, ketoconazole, miconazole, amphotericin B, and nystatin was determined. The isolates were obtained from 559 patients who had attended the UK dental hospital departments in Cardiff, Belfast, Glasgow or London. Antifungal susceptibility was assessed using a broth microdilution method following the National Committee for Clinical Laboratory Standards (NCCLS) M27-A guidelines. The majority of the test strains were C. albicans (n = 521) with few of these being resistant to fluconazole (0.3%). A low incidence of fluconazole resistance (0-6.8%) was similarly evident with all non albicans species (Candida glabrata, 5 of 59 resistant; Candida krusei, 0 of 7 resistant; Candida tropicalis, 0 of 13 resistant; Candida parapsilosis, 0 of 12 resistant; other Candida species, 0 of 6 resistant). Voriconazole, ketoconazole, and miconazole also revealed high activity against both C. albicans and non albicans isolates, and 23.7% of C. glabrata isolates were found to be resistant to itraconazole. There was little difference in the antifungal susceptibilities of Candida isolated from patients who had a history of previous antifungal therapy compared with those who had not received antifungal treatment. In summary, this surveillance study of antifungal susceptibility of oral candidal isolates in the UK, through the collaboration of four dental hospitals, demonstrates that oral Candida species have a high level of susceptibilities to a range of antifungal agents.     

白芍总苷和盐酸小蘖碱的抗口腔念珠菌活性研究

目的检测白芍总苷和盐酸小蘖碱(C20H18CINO4)的抗口腔念珠菌活性。方法收集口腔念珠菌正常共生菌和致病菌,经YBCTestKit鉴定念珠菌种类;依据美国临床实验室标准委员会(NCCLS)的M27-A2标准方案测定临床分离株对氟康唑、白芍总苷、盐酸小蘖碱的药物敏感性。结果白芍总苷和盐酸小蘖碱对口腔念珠菌正常共生菌和致病菌均具有抗念珠菌活性,尤其具有抗光滑念珠菌的活性。结论白芍总苷和盐酸小蘖碱的抗真菌机制可能和氟康唑不同;白芍总苷和盐酸小蘖碱可用于治疗和预防口腔念珠菌感染。     

Epidemiology of oral yeast colonization and infection in patients with hematological malignancies,head neck and solid tumors

J Oral Pathol Med (2011) 40 : 83–89 Background: The aim of this study was to investigate the epidemiology of oral yeast colonization and infection amongst cancer patients. Methods: Patients with solid tumor, head‐neck cancer or hematological malignancy were recruited into the study. Demographic data on age, gender, type of cancer, preceding treatment with antibiotics, anti‐fungal agents, chemotherapy, radiation or surgery and presence of dentures were recorded on admission. Oral examination and microbial swabs were obtained and yeast culture, identification and antifungal susceptibility performed. Results: Oral yeast colonization was prevalent in 56.8% (227/400) of all cancer patients and 18.9% (43/227) of those had clinical and microbiological evidence of infection. The incidence of oral candidiasis in yeast colonized patients was highest in head neck cancer (29.2%) followed by hematological malignancies (20.5%) and solid tumor (17%) patients. Age and dentures were identified as independent risk factors associated with yeast carriage. Candida albicans was the dominant (74%) species (497.5 per 1000 cancer admissions) followed by C. glabrata (11.5%), C. tropicalis (2.6%), C. krusei (2.6%) and C. parapsilosis (1.9%). The overall resistance to azoles was 28.2% (75/266). Resistance to specific drugs was seen for fluconazole (4.5%), itraconazole (11.7%), ketoconazole (11.3%), voriconazole (0.75%) and caspofungin (41.1%) but none to amphotericin B or nystatin. Conclusions: The highest incidence of oral candidiasis amongst cancer patients was seen in head neck cancers. The majority of infections were caused by C. albicans but almost one third of patients harbored non‐C. albicans strains such as C. glabrata which were often more resistant to anti‐fungal agents.     

Heterogeneity in antifungal susceptibility of clones of Candida albicans isolated on single and sequential visits from a HIV-infected southern Chinese cohort

The increased frequency and severity of candidal infections in human immunodeficiency virus (HIV)-infected individuals has prompted the wide use of antifungals, such as amphotericin B, ketoconazole, and fluconazole, resulting in the emergence of drug-resistant strains of Candida albicans. To study this phenomenon in an ethnic Chinese cohort, we isolated multiple colonies of Candida from the oral cavities of 16 HIV-infected patients on single and subsequent sequential visits over a period of 12 months. Ten of the 16 patients had sporadic episodes of oropharyngeal candidiasis (Group A), while the remainder were asymptomatic with respect to this condition (Group B). Oral rinses were collected and immediately processed in the laboratory for the isolation of C. albicans in a standard manner. A total of 433 C. albicans isolates were tested for their susceptibility to amphotericin B, ketoconazole and fluconazole by an agar diffusion method using the commercially available E-test. All tested isolates demonstrated variable susceptibility to amphotericin B, ketoconazole and fluconazole. The minimum inhibitory concentration (MIC) of the isolates for amphotericin B, ketoconazole and fluconazole ranged from <0.002-1.5 microg/ml, <0.002-4.0 microg/ml and <0.016-32 microg/ml, respectively. Sequential isolates of a few patients demonstrated variable susceptibility to all the antifungals, and no discernible MIC pattern emerged either in group A or B over time. Interestingly, significant variation in antifungal susceptibility was also noted in isolates obtained from the same patient on a single visit. Sequential yeast isolates in 9 of 16 patients (56%) demonstrated significant differences in MIC within and between visits for both amphotericin B and ketoconazole, while a lower percentage--44%(7/16)--exhibited this trait for fluconazole. Our study demonstrates the diversity in antifungal susceptibility in either commensal or "infective" oral strains of C. albicans in HIV disease, and shows the need for vigilance for the emergence of resistant strains, and for frequent antifungal susceptibility studies.