Hibiscus sabdariffa extract inhibits in vitro biofilm formation capacity of Candida albicans isolated from recurrent urinary tract infections

Objective:To explore the prevention of rerurrent candiduria using natural based approaches and to study the antimicrobial effect of Hibiscus sabdariffa(H.sabdariffa) extract and the biofilm forming capacity of Candida albicans strains in the present of the H.sabdariffa extract.Methods:In this particular study,six strains of fluconazole resistant Candida albicans isolated from recurrent candiduria were used.The susceptibility of fungal isolates,time-kill curves and biofilm forming capacity in the present of the H.sabdariffa extract were determined.Results:Various levels minimum inhibitory concentration of the extract were observed against all the isolates.Minimum inhibitory concentration values ranged from 0.5 to 2.0 mg/mL Timekill experiment demonstrated that the effect was fungistatic.The biofilm inhibition assay results showed that H.sabdariffa extract inhibited biofilm production of all the isolates.Conclusions:The results of the study support the potential effect of H.sabdariffa extract for preventing recurrent candiduria and emphasize the significance of the plant extract approach as a potential antifungal agent.

Alternative Oxidase Promotes Biofilm Formation of Candida albicans

This study was designed to analyze the effect of the mitochondrial respiratory pathways of Candida albicans （C. albicans） on the biofilm formation. The 2, 3-bis （2-methoxy- 4-nitro-5-sulfophenyl）-2H-tetrazolium-5-carboxanilide （XTT） reduction assay was used to measure the metabolic activities of biofilms formed by the C. albicans which were cultured in the presence of respiratory pathways inhibitors. The biofilms formed by the wide type （WT）, GOA1-deleted （GOA31）, GOAl-reconstituted （GOA32）, AOXla-deleted （AOX1） and AOX1b- deleted （AOX2） C. albicans strains were examined by the XTT reduction assay and fluorescence microscopy. The expression of adhesion-related genes BCR1, ALS1, ALS3, ECEI and HWP1 in the biofilms formed by the above five C. albicans strains was detected by real time polymerase chain reaction. It was found that the metabolic activity of biofilms formed by C. albicans was decreased in the presence of alternative oxidase inhibitor whereas it was increased in the presence of classical mitochondrial respiratory pathway complex Ⅲ or complex IV inhibitor. AOX1 strain produced scarce biofilms interspersed with few hyphal filaments. Moreover, no significant changes in the expression of BCR1 and ALS3 were observed in the AOX 1 strain, but the expression of ALS1 and ECE1 was down-regulated, and that of HWP1 was up-regulated. These results indicate that both AOX1 and AOX2 can promote the biofilm formation. However, AOX1a primarily plays a regulatory role in biofilm formation in the absence of inducers where the promoting effect is mainly achieved by promoting mycelial formation.

Identification of a Candida albicans Biofilm Inhibitor

Candida albicans proliferates in the skin and oral cavity and is the causative agent of candida dermatitis and oral candidiasis. C. albicans is known to form biofilms on oral mucosa and denture surfaces. Formation of biofilms deteriorates the permeability of antifungal drugs, decreasing their effectiveness. Therefore, in this study, I identified a compound with inhibitory activity against C. albicans biofilm formation. Heat shock protein 90 was selected as the target protein, and a potential ligand for the same was extracted and identified as 2-(4-methylpiperazin-1-yl)cyclopentanol. C. albicans was then cultured with varying concentrations of this compound: 0 mmol/L, 0.63 mmol/l. 2.5 mmol/l, and 10 mmol/l, and biofilm formation was measured via crystal violet assay. The findings demonstrated that 2-(4-methylpiperazin-1-yl)cyclopentanol substantially inhibits biofilm formation when added at a concentration of 0.63 mmol/l or higher. It is suggested that C. albicans could be eliminated more efficiently using this compound in combination with the existing antifungal drug miconazole. Further, the compound may also be useful as a disinfectant for medical devices, such as catheters, to prevent the formation of C. albicans biofilms.

肺癌患者血清IL-1β、CAR及HBP水平与化疗期间继发肺部白色假丝酵母菌感染的关系

目的探讨肺癌患者血清白细胞介素-1β(IL-1β)、C反应蛋白与白蛋白比值(CAR)及肝素结合蛋白(HBP)水平与化疗期间继发肺部白色假丝酵母菌感染的关系。方法选取2018年1月至2022年4月该院收治的肺癌患者175例,均予以化疗方案,根据其是否继发肺部白色假丝酵母菌感染分为感染组(37例)与非感染组(138例)。比较两组临床资料、血清IL-1β、HBP水平及CAR,采用多因素Logistic回归分析肺癌患者化疗期间继发肺部白色假丝酵母菌感染的影响因素,采用受试者工作特征(ROC)曲线分析血清IL-1β、CAR、HBP对化疗期间继发肺部白色假丝酵母菌感染的预测价值,比较不同血清IL-1β、HBP水平及CAR的肺癌患者预后情况。结果感染组吸烟、病理分期、糖尿病、化疗周期、慢性阻塞性肺疾病、解剖部位与非感染组比较,差异有统计学意义(P<0.05);感染组血清IL-1β、HBP水平及CAR均高于非感染组(P<0.05);多因素Logistic回归分析结果显示,吸烟、糖尿病、解剖部位、慢性阻塞性肺疾病、病理分期、化疗周期及血清IL-1β、HBP、CAR均为肺癌患者化疗期间继发肺部白色假丝酵母菌感染的影响因素(P<0.05)。血清IL-1β、CAR、HBP单独预测肺部白色假丝酵母菌感染的曲线下面积(AUC)分别为0.779、0.732、0.796,三者联合预测的AUC为0.931,灵敏度、特异度分别为86.49%、90.58%;IL-1β、CAR、HBP高水平亚组的肺癌患者生存率明显低于低水平亚组(P<0.05)。结论肺癌患者血清IL-1β、HBP水平及CAR升高与化疗期间继发肺部白色假丝酵母菌感染有关,检测其水平有助于预测肺部白色假丝酵母菌感染及死亡风险。

Kinetics of <i>Candida albicans</i>and <i>Staphylococcus aureus</i>Biofilm Initiation on Herpes Simplex Virus (HSV-1 and HSV-2) Infected Cells

This study examines the kinetics of S. aureus and C. albicans adherence as it relates to HSV replication and corresponding dynamic display of shared receptors. HeLa cells infected for various times with HSV-1 gL86 or HSV-2 333gJ-(MOI 50) were incubated with S. aureus ATCC 25923 or C. albicans yeast and CFU measured. Over time, S. aureus adherence to HSV-1 infected cells was relatively stable for 45 min then decreased to 0.8 of virus-free control, before cycling at 15-to-30 min intervals. In contrast, staphylococcal adherence to HSV-2 infected cells proceeded at a more gradual rate, increasing to control levels at ~105 min before decreasing to a nadir at 165 min. Yeast adherence to HSV-1 infected cells remained relatively unchanged for the first 75 min then increased 2-fold before returning to its original level. This pattern is repeated over the next 90 min. While a similar pattern with C. albicans and HSV-2 was measured, it occurred more rapidly. Our model shows that while the interaction of both HSV-1 and HSV-2 with S. aureus is both dynamic and inhibitory, C. albicans interaction with HSV-2 is more permissive than HSV-1. However, the interaction of both microbes with HSV-infected cells in this model system appears to be independent of α5B1, CD36 and HSP60 viral-regulated receptor expression. These findings indicate that microbiome interactions across taxonomic kingdoms are more complex than previously thought.

A novel integrated step-feed biofilm process for the treatment of decentralized domestic wastewater in rural areas of China

For wastewater treatment in rural areas, a novel three-stage step-feed wastewater treatment system, combined with a drop-aeration biofilm process, was tested in the laboratory to investigate its performance in removing suspended solids （SS）, chemical oxygen demand （COD）, NH4＋-N, total nitrogen （TN）, and total phosphorus （TP）. The removal rates of SS, COD and NH4＋-N were 90%, 80%, and 90% in efluent concentrations less than 10 mg/L, 50 mg/L and 8 mg/L, respectively. The TP removal rate was less satisfactory. The C/N ratio in the raw wastewater was often less than 3.5, and the removal efficiency of TN was therefore limited. A carbon-release batch experiment was carried out to measure the feasibility of enhancing denitrification at low influent C/N ratios. The result showed that the C/N could be over 9.0 in the supernatant. Polymerase chain reaction denaturing gradient gel electrophoresis technology was used to reveal the changes in the bacterial community during different stages of the integrated step-feed biofilm process. The results showed that banding patterns and the distribution of dominant bands for the same experimental period in different aerobic zones were similar. Phylogenetic analysis indicated that lanes 10, 11 and 12, which presented three aerobic zones at the same operation period, had the closest phylogenetic relationship among the lanes.

Cis-2-dodecenoic Acid Mediates Its Synergistic Effect with Triazoles by Interfering with Efflux Pumps in Fluconazole-resistant Candida albicans

Objective To evaluate the synergy of the Burkholderia signaling molecule cis-2-dodecenoic acid(BDSF) and fluconazole(FLU) or itraconazole(ITRA) against two azole-resistant C. albicans clinical isolates in vitro and in vivo. Methods Minimum inhibitory concentrations(MICs) of antibiotics against two azole-resistant C. albicans were measured by the checkerboard technique, E-test, and time-kill assay. In vivo antifungal synergy testing was performed on mice. Analysis of the relative gene expression levels of the strains was conducted by quantitative reverse-transcription polymerase chain reaction(qR T-PCR). Results BDSF showed highly synergistic effects in combination with FLU or ITRA with a fractional inhibitory concentration index of ≤ 0.08. BDSF was not cytotoxic to normal human foreskin fibroblast cells at concentrations of up to 300 μg/mL. The qR T-PCR results showed that the combination of BDSF and FLU/ITRA significantly inhibits the expression of the efflux pump genes CDR1 and MDR1 via suppression of the transcription factors TAC1 and MRR1, respectively, when compared with FLU or ITRA alone. No dramatic difference in the mR NA expression levels of ERG1, ERG11, and UPC2 was found, which indicates that the drug combinations do not significantly interfere with UPC2-mediated ergosterol levels. In vivo experiments revealed that combination therapy can be an effective therapeutic approach to treat candidiasis. Conclusion The synergistic effects of BDSF and azoles may be useful as an alternative approach to control azole-resistant Candida infections.

Update on the Fungal Biofilm Drug Resistance and Its Alternative Treatment

Candida albicans (C. albicans) and Aspergillus fumigatus (A. fumigatus) are the two main pathogens in the clinical setting to cause serious, sometimes, lethal fungal infections. Immunocompromised patients fall victims to these fungi, with a mortality rate rising drastically over the past decades. This is in correlation with the fact that conventional antifungals are no longer capable of completely eradicating the disease, or if so, high doses are usually required to do so, leading to eventual resistance to those drugs and severe side effects. High drug resistance is in association with the discovery that these opportunistic pathogens have the ability to develop a multicellular complex, known as biofilm. Biofilms prevent drugs from reaching the fungal cells by sequestering them in their extracellular matrix. Other factors such as extracellular DNA, persister cells or heat shock protein 90 (Hsp90) also play a role in biofilm and contribute to drug recalcitrance. With the discovery of new antifungals lagging behind, scientists focused on other more profitable ways to counteract this phenomenon. Combination of two or more antifungals was found effective but came with serious drawbacks. Natural plant extracts, such as traditional Chinese medicine have also been demonstrated in vitro to possess antimicrobial actions. Great interest was directed towards their use with conventional antifungal agents with a possibility of lowering the necessary concentration required to inhibit the growth of fungi. This review aims in understanding the different factors contributing to clinical drug resistance and evaluating the effect of combination therapy and natural products on those cases difficult to treat.

PAC对生物膜性能及煤气化废水处理效能影响研究

以弹性立体填料为载体、连续流进水方式运行两组生物膜反应器。通过不断提高进水负荷、降低C/N的方式驯化生物膜,探究投加20 mg/L聚合氯化铝(PAC)对生物膜性能及低C/N煤气化废水处理效果的影响。通过对污染物去除效能监测发现,未投加PAC的R1组和投加PAC的R2组两组生物膜耐冲击负荷能力良好,有机物去除效果稳定;后期稳定运行时R2组和R1组TN去除率分别达84%、79.4%以上,脱氮性能良好,且PAC的投加使除磷率达98%以上。由数据分析可知,20 mg/L PAC的投加有利于提高生物膜生物量、促进胞外聚合物(EPS)中蛋白、多糖的分泌;SEM及菌群分析发现PAC的投加改变了微生物种群结构、驯化了脱氮除磷优势菌种。通过合适的驯化培养,可以实现PAC耦合生物膜法对低C/N工业煤气化废水较好的处理效果,具有实际应用潜力。

活性污泥-悬浮生物膜系统处理低C/N污水深度脱氮性能

通过农业废弃物玉米芯悬浮生长生物膜的载体,构建了活性污泥-悬浮生物膜混合系统,以SBR工艺运行方式对低浓度低C/N污水的深度脱氮性能进行了研究.探究了挂膜启动阶段系统脱氮效果;在工艺稳定运行后,考察了温度、HRT、DO、进水C/N、进水pH等参数对工艺脱氮性能的影响.经过24 d挂膜后,结合污染物去除情况及镜检显示生物膜挂膜成功.运行结果表明,以预处理后的生活污水作为模拟原水,控制反应温度为26—30℃,HRT=8 h,COD/TN为(4.0±0.1),DO=(2.2±0.1)mg·L^(-1),进水pH=(8.0±0.1)的条件下,系统达到最佳运行条件,COD、NH_(4)^(+)-N、TN平均去除率分别为70.2%、94.8%和80.8%,平均出水COD、NH_(4)^(+)-N、TN浓度分别为14.89 mg·L^(-1)、0.57 mg·L^(-1)和2.40 mg·L^(-1).好氧阶段DO浓度对TN去除率有一定的影响,当好氧阶段DO浓度为(2.2±0.1)mg·L^(-1)时,TN去除率达到峰值84.38%.结果表明,活性污泥-悬浮生物膜混合系统处理低浓度低C/N污水具有优良性能,为低浓度低C/N污水的深度脱氮及玉米芯的资源化利用提供新的思路.

C/N对Atmosphere-Exposed Biofilm体系处理特性影响

采用Atmosphere-Exposed Biofilm体系处理模拟废水,考察分析了不同C/N质量比(5、10、15、50、75及100)条件下体系的处理特性。结果表明,随着C/N增加,体系中COD(化学需氧量)去除率分别为81.9%、86.4%、88.5%、93.8%、94.4%和95.1%,呈波动上升趋势,NH4+-N(氨氮)去除率分别为91.4%、87.5%、81.1%、74.7%、75.3%和73.6%,大体呈波动下降趋势,而TN(总氮)去除率分别为41.4%、57.4%、65.3%、71.5%、72.9%和70.2%,TP(总磷)去除率分别为57.1%、61.7%、64.7%、74.2%、73.4%和71.1%,TN和TP去除率大体呈先增大后减小的趋势。在低C/N条件下(C/N为5、10、15),体系中污染物去除率变化显著,而在高C/N条件下(C/N为50、75、100),去除率变化不显著。在C/N为5~100时,C/N与COD、NH4+-N、TN及TP进出水浓度比(Se/So)具有较好的相关性,拟合方程能较好的预测体系的处理效果。

Phenazine Methosulphate Modulating the Expression of Genes Involved in Yeast to Hyphal Form Signal Transduction in <i>Candida albicans</i>

Candida albicans has ability to switch from yeast to hyphal form which is an important virulence factor. The objective of the research is to study the effect of Phenazine Methosulphate (PMS) on virulence factors and to study expression profile in yeast to hyphal form transition in C. albicans. Phenazine Methosulphate (PMS) acted as an inhibitor of yeast to hyphal form transition, adhesion and biofilm formation in C. albicans. RTPCR study demonstrated that PMS Modulate the expression of genes involved in Ras1-cAMP-Efg1 and Cek1-MAPK signal transduction pathways. Cell cycle of C. albicans was arrested at S phase on treatment of PMS. Hyphal suppressor genes like Tup1, Mig1 and Nrg1 were upregulated by PMS. Based on our data on expression of genes during yeast to hyphal form transition in presence and absence of PMS, we hypothesize that inhibition of hyphal formation may be due to the overexpression of negative regulators of hyphal growth. Targeting of hyphal specific genes involved in these pathways may be a promising strategy for anti-candida drug development.

EFFECTS OF SYSTEMIC FLUCONAZOLE THERAPY ON IN VITRO ADHESION OF CANDIDA ALBICANS TO BUCCAL EPITHELIAL CELLS AND CHANGES OF THE CELL SURFACE PROTEINS OF THE EPITHELIAL CELLS

This paper presented the effects of systemic fluconazole therapy via intravenous (IV) and oral (PO) administrations on the adhesion of Candida albicans (C. albicans) to the buccal epithelial cells (BEC) from five treated patients with three candidosis, one mucormycosis and one sporotrichosis and at the same time.an analysis of the cell surface proteins involving candidal adherent receptor in the BEC of the patients in the course of 7 days were exposed to ￣3H-leucine radiolabeled C. albicans for in vitro candidal adherent assay.and the BEC from first intake day and the last intake day of the patients were extracted by dithiothreitol (DTT)-iodoacetamide treatment for SDSPAGE. These results indicate that the systemic fluconazole therapy results in the inhibitory effect of candidal adhesion to BEC of treated patients to prevent them from oral candidosis for a prolonged time, which is based on the absent surface protein (35 KDa) of the BEC.

Effects of Cinnamaldehyde, Ocimene, Camphene, Curcumin and Farnesene on Candida albicans

Efficacy of five plant molecules against thirty three clinical isolates and two standard strains of C. albicans, differentially susceptible to fluconazole (FLC) is tested in this study. Effect on biofilm (adhesion, development and maturation) formation, morphogenesis and synergy with fluconazole (FLC) against a FLC resistant strain of Candida albicans ATCC 10231 is also evaluated. All the plant molecules tested were equally effective against isolates and strains of C. albicans (N = 35) tested in this study. Cinnamaldehyde was found most effective against planktonic growth followed by ocimene. Both the molecules exhibited fungicidal activity and killed 99.9% of inoculum within 80 and 20 min of exposure respectively at 0.62 mM and 176.8 mM concentrations. Curcumin (5 - 20 mM), camphene (8 - 32 mM) and farnesene (25 - 100 mM), although inhibited planktonic growth, were fungistatic. All the five plant molecules tested in this study inhibited morphogenesis significantly and exhibited considerable activity against biofilm formation. Inhibition of biofilm was found to be stage specific i.e. efficacy was more against adhesion followed by developing and mature biofilm. Plant molecules tested exhibited excellent synergy with fluconazole. However FIC index values 0.155, 0.062 and 0.046 indicate that ocimene was the most effective synergistic molecule inhibited planktonic growth, developing biofilm and mature biofilm growth respectively at very low concentrations. This is the first report of anti-Candida activity of three terpenoids viz. ocimene, farnesene and camphene against planktonic & biofilm growth, morphogenesis as well as synergy with FLC. Plant molecules tested in this study may find use in antifungal chemotherapy individually and or in a combination with FLC.

TpbA通过调节c-di-GMP抑制鲍曼不动杆菌ATCC17978生物膜的形成

目的分析生物膜形成相关的酪氨酸磷酸酶A(TpbA)经调节3,5-环鸟苷二磷酸(c-di-GMP)影响鲍曼不动杆菌ATCC17978生物膜的形成。方法通过上海生工合成TpbA基因序列,构建pET-28a-TpbA载体,原核重组表达目的蛋白TpbA经亲和层析纯化后并用western blot验证,将该载体转入鲍曼不动杆菌ATCC17978,采用western blot和磷酸酶活性实验鉴定TpbA表达及活性,分析c-di-GMP表达水平及生物膜形成情况。结果在成功构建pET-28a-TpbA载体并证实表达TpbA的基础上,将该载体转入鲍曼不动杆菌ATCC17978,western blot表明TpbA过表达(P<0.05),磷酸酶活性实验证实过表达的TpbA具有酶活性(P<0.05)。进一步分析发现,ATCC17978中TpbA过表达能够降低c-di-GMP的水平(P<0.05),表明TpbA能够有效调节鲍曼不动杆菌的c-di-GMP。ATCC17978中c-di-GMP相关的生物膜形成在TpbA过表达作用下能够被显著抑制(P<0.05)。结论本研究初步证实了TpbA通过调节c-di-GMP,可以抑制ATCC17978生物膜形成,为抑制鲍曼不动杆菌生物膜的形成提供了新的潜在靶点和实验数据。

美洲大蠊提取物CⅡ-3对白假丝酵母菌生物膜形成的作用

目的:探讨美洲大蠊提取物CⅡ-3(以下简称“CⅡ-3”)对白假丝酵母菌生物膜形成的影响,为研发抗真菌生物膜药物奠定基础。方法:将CⅡ-3加入白假丝酵母菌液与生物膜共孵育,分别设CⅡ-3高剂量组、CⅡ-3低剂量组、阳性对照组和阴性对照组,采用形态观察法及MTT法检测CⅡ-3对白假丝酵母菌生物膜形成的作用,计算生物膜抑制率评估不同浓度CⅡ-3对不同生长阶段白假丝酵母菌生物膜的作用效果。结果:CⅡ-3作用下白假丝酵母菌仍能形成生物膜样结构,高剂量组生物膜抑制率分别为25.1%和13.9%,均低于氟康唑生物膜抑制率(79.3%);与不同生长阶段白假丝酵母菌生物膜孵育时,CⅡ-3对生长8 h生物膜抑制率最高(61.7%),其次是生长16 h和24 h生物膜的抑制率(35.4%和21.9%),氟康唑仅对生长4 h白假丝酵母菌生物膜有明显抑制作用(抑制率75.5%),对其他生长阶段白假丝酵母菌生物膜抑制作用不显著,CⅡ-3对白假丝酵母菌聚集和成熟期生物膜的抑制作用是氟康唑的2~9倍。结论:CⅡ-3主要在聚集和成熟阶段抑制白假丝酵母菌生物膜形成,抑制作用未见明显量效关系。

爱媛类芽孢杆菌抗菌肽对白色念珠菌生物膜的抑制作用机制

研究爱媛类芽孢杆菌抗菌肽对白色念珠菌生物膜的抑制作用,采用微量二倍稀释法和时间-杀菌曲线测定抑制效果,显微镜观察对白色念珠菌芽管和菌丝形成的影响,2,3-二(2-甲氧基-4-硝基-5-磺酸基苯基)-2H-四唑-5-甲酰苯胺法研究对生物膜、预成型生物膜形成和成熟生物膜清除率的影响,荧光探针观察对生物膜结构和膜内菌体状态的影响,平板涂布法和实时聚合酶链式反应测定生物膜内活菌数量和相关基因表达水平。结果表明,抗菌肽对白色念珠菌的最小抑菌浓度为8.28 AU/mL。抗菌肽能降低白色念珠菌的芽管形成率,阻止菌丝的生成,使其以酵母形式存在。抗菌肽对生物膜的形成和清除产生影响,能在较短时间内破坏生物膜的结构完整性,导致菌体受损和死亡,减少膜内菌落数量。在基因水平上,抗菌肽可降低多个生物膜形成相关的基因(如ALS1、ALS3、HWP1、EFG1、ECE1和UME6)的表达水平,从而抑制生物膜的形成。研究证明抗菌肽能够有效抑制白色念珠菌生物膜形成、成熟膜清除、成膜基因表达等,结果可为白色念珠菌新型抑菌物质的开发奠定理论基础,为食品病原微生物污染防治和食品质量安全保障提供依据。

抗白念珠菌新型化合物及靶点的研究进展

近年来,真菌感染肆虐全球,每年感染约数十亿人,其中死亡人数近150万人,严重威胁着人类的生命安全。白念珠菌是真菌感染中最主要的的病原体之一,它引起的侵袭性念珠菌病死亡率高达40%~50%,但是由于抗真菌药物的种类有限,并且耐药现象越来越严重,使得白念珠菌的临床治疗尤为棘手。因此寻找新型抗真菌化合物,根据抗真菌的独特的分子靶标开发靶向药物尤为重要。文章综述了近几年一些具有较大潜力的新型抗白念珠菌化合物以及一些新型抗真菌靶点。

多肽bCAT通过下调白念珠菌HWP1基因表达抑制生物被膜的形成机制

目的明确多肽bCAT抑制白念珠菌生物被膜形成能力,并探索其与黏附基因HWP1表达的关系。方法标准菌株白念珠菌ATCC10231和临床菌株作为研究对象,XTT法检测其生物被膜形成能力,bCAT抗浮游白念珠菌的MIC值以CLSI-M27-A3方法确定,XTT法及菌落计数检测bCAT抑制生物被膜形成作用,并计算代谢活性确定抑制50%生物被膜形成的MIC(BIC_(50)),bCAT减少白念珠菌的黏附作用经倒置显微镜下观察及菌落计数法检测,并采用RT-PCR通过2^(-ΔΔCt)法计算HWP1的表达量。统计方法为单因素方差分析,组内比较采用Dunnett T3检验。结果标准菌株及临床菌株均有较强生物被膜形成能力。bCAT抗浮游状态的白念珠菌MIC值为40~80μmol/L,BIC_(50)为80~160μmol/L;并且bCAT能减少白念珠菌的黏附作用,空白对照组菌落计数为(27 822.22±2 472.74)cfu,bCAT浓度为160、80、40、20、10μmol/L时的菌落个数分别为(5 355.55±1 264.03)cfu、(11 377.78±2 232.58)cfu、(17 488.89±1 136.27)cfu、(22 377.78±3 521.99)cfu、(26 044.44±1 329.57)cfu。组间差异具有统计学意义(F=147.018,P=0.001),组内比较发现160、80、40μmol/L处理组与不含bCAT时差异具有统计学意义(P<0.05)。RT-PCR发现160μmol/L处理组HWP1相对表达量为空白对照组的12.24%。结论 bCAT能有效抑制白念珠菌生物被膜形成,其机制可能与降低HWP1基因的表达从而减少白念珠菌的黏附有关。具有一定的临床前景。