Biofilm Alterations on the Stepwise Acquisition of Fluconazole-resistant Candida Albicans Isolates

Objectives:By assessing and comparing the phenotypic changes on the stepwise acquisition of fluconazole resistant Candida albicans isolates,we could find and describe the relationship between drug resistance and biofilm formation ability in a series of clonal strains.Methods:We performed antifungal susceptibility of five drugs(fluconazole,itraconazole,voriconazole,caspofungin and amphotericin B)to further verify the antifungal activity of the six isolates in vitro.Then we combined hyphal formation assay,cell surface hydrophobicity test positively related to adherence ability,and biofilm assays in vitro to observe and compare the phenotypic characteristics of our six clonal strains.Results:Biofilm capability is enhanced for four drug-intermediate strains,whereas the initial susceptible strain and the final resistant strain are both poor in adherence,hyphal growth and biofilm formation.Conclusions:It was suggested that the biofilm formation ability were not absolutely related to the degree of fluconazole resistance.

Antifungal activity of four honeys of different types from Algeria against pathogenic yeast:Candida albicans and Rhodotorula sp.

Objective:To evaluate the antifungal activity of four honeys of different types from Algeria against pathogenic yeast i.e.Candida albicans(C.albicans) and Rhoddtorula sp.Methods:Four Algeria honeys of different botanical origin were analvzed to test anlilungal effect against C.albicans,and Rhodotorula sp.Different concentrations(undiluted,10%,30%,50%and 70%w/v) of honey were studied in vitro for their antifugal aclivity using C.albicans and Rhodotorula sp.as fungal strains.Results:The range of the c liameter of zone of inhibition of various concentrations ol tested honeys was(7-23 mm) for Rhodotorula sp.,while C.albicans showed clearly resistance towards all concentrations used.The MICs of tested honey concentrations against C.albicans and Rhodotorula sp.were(70.09-93.48)%and(4.90-99.70)%v/v,respectively.Conclusions:This study demonstrales that,in vitro,these natural products have clearly an antifungal activity against Rhodotorula sp.and C.albicans.

Additive potential of ginger starch on antifungal potency of honey against Candida albicans

Objective:To evaluate the additive action of ginger starch on the antifungal activity of honey against Candida albicans(C.albicans).Methods:C.albicans was used to determine the minimum inhibitory concentration(MIC)of four varieties of Algerian honey.Lower concentrations of honey than the MIC were incubated with a set of concentrations of starch and then added to media to detennine the minimum additive inhibitory concentration(MAIC).Results:The MIC for the four varieties of honey without starch against C.albicans ranged between 38%and 42%(v/v).When starch was incubated with honey and then added to media,a MIC drop was noticed with each variety.MAIC of the four varieties ranged between 32%honey(v/v)with 4%starch and 36%honey(v/v) with 2%starch.Conclusions:The use of ginger starch allows honey benefit and will constitute an alternative way against the resistance to antifungal agents.

Effect of ethanolic extract of Ecballium elaterium against Staphylococcus aureus and Candida albicans

Objective:To evaluate the antimicrobial activity of ethanolic extract of Ecballium elaterium(E. elaterium)fruits alone against Staphylococcus aureus(S.aureus) strains and Candida albicans(C.albicans)strains,or in combination with penicillin against Staphylococcus areus strains. Methods:Evaluation of the antimicrobial activity or synergy interaction was carried out using microdilution method.Results:The results showed that ethanolic extract of E.elaterium fruits has antimicrobial activity against methicillin resistant S.aureus(MRSA),methicillin sensitive S. aureus(MSSA) and C.albicans.This extract showed a significant decrease in minimum inhibitory concentrations(MIC)of penicillin against both MRSA and MSSA strains.Fractional inhibitory concentration index(FIC)between penicillin and ethanolic extract of E.elaterium fruits against these test strains was less than 0.5.Conclusions:This study suggests that ethanolic extract of E.elaterium fruits has antimicrobial activity against S.aureus and C.albicans and there is a possibility of concurrent use of penicillin and E.elaterium extract in combination in the treatment of infections caused by MRSA and MSSA strains.A wider study is needed to identify the effective components,the mode of action and the possible toxic effect in vivo of these ingredients.

A transmission electron microscopy study of the diversity of Candida albicans cells induced by Euphorbia hirta L.leaf extract in vitro

Objective:To determine the major changes in the microstructure of Candida albicans(C. albicans) after treatment with Euphorbia hirta(E.hirta) L.leaf extract.Methods:Transmission electron microscopy was used to study the ultrastructural changes caused by E.hirta extract on C. albicans cells al various exposure time.Results:It was found that the main abnormalities were the alterations in morphology,lysis and complete collapse of the yeast cells after 36 h of exposure to the extract.Whereas the control cultures showed a typical morphology of Candida with a uniform central density,typically structured nucleus,and a cytoplasm with several elements of endomembrane system and enveloped by a regular,intact cell wall.Conclusions:The significant antifungal activity shown by this methanol extract of E.hirta L.suggests its potential against infections caused by C.albicans.The extract may be developed as an anticandidal agent.

Assessment of antifungal activity of herbal and conventional toothpastes against clinical isolates of Candida albicans

Objective:To detect the anticandidal activity of nine toothpastes containing sodium fluoride, sodium monofluorophosphate and herbal extracts as an active ingredients against 45 oral and non oral Candida albicans(C.albicans) isolates.Methods:The antifungal activity of these toothpaste formulations was determined using a standard agar well diffusion method.Statistical analysis was performed using a statistical package,SPSS windows version 15,by applying mean values using one-way ANOVA with post-hoc least square differences(LSD) method.A P value of less than 0.05 was considered significant.Results:All toothpastes studied in our experiments were effective in inhibiting the growth of all C.albicans isolates.The highest anticandidal activity was obtained from toothpaste that containing both herbal extracts and sodium fluoride as active ingredients, while the lowest activity was obtained from toothpaste containing sodium monofluorophosphate as an active ingredient.Antifungal activity of Parodontax toothpaste showed a significant difference(P<0.001) against C.albicans isolates compared to toothpastes containing sodium fluoride or herbal products.Conclusions:In the present study,it has been demonstrated that toothpaste containing both herbal extracts and sodium fluoride as active ingredients are more effective in control of C.albicans,while toothpaste that containing monofluorophosphate as an active ingredient is less effective against C.albicans.Some herbal toothpaste formulations studied in our experiments,appear to be equally effective as the fluoride dental formulations and it can be used as an alternative to conventional formulations for individuals who have an interest in naturally-based products.Our results may provide invaluable information for dental professionals.

In vitro effects of Salvia officinalis L.essential oil on Candida albicans

Objective:To determine the anticandidal activities of Salvia officinalis L.(S.officinalis)essential oil against Candida albicans(C.albicans)and the inhibitory effects on the adhesion of C.albicans to polymethyl methacrylate(PMMA)resin surface.Methods:Disc diffusion method was first used to test the anticandidal activities of the S.officinalis L.essential oil against the reference strain(ATCC 90028)and 2 clinical strains of C.albicans.Then the minimal inhibitory concentration(MIC)and minimal lethal concentration(MLX)were determined by modified membrane method.The adhesion of C.albicans to PMMA resin surface was assessed after immersion with S.officinalis L.essential oil at various concentrations of 1XMIC.0.5XMIC and 0.25XMIC at room temperature for30 min.One-way ANOVA was used to compare the Candida cell adhesion with the pretreatment agents and Tukey's test was used for multiple comparisons.Results:5.officinalis L.essential oil exhibited anticandidal activity against all strains of C.albicans with inhibition zone ranging from 40.5 mm to 19.5 mm.The MIC and MLC of the oil were determined as 2.780 g/L against all test strains.According to the effects on C.albicans adhesion to PMMA resin surface,it was found that immersion in the essential oil at concentrations of 1XMIC(2.780 g/L).0.5XMIC(1.390 g/L)and0.25XMIC(0.695 g/L)for 30 min significantly reduced the adhesion of all 3 test strains to PMMA resin surface in a dose dependent manner(P<0.05).Conclusions:S.officinalis L.essential oil exhibited anticandidal activities against C.albicans and had inhibitory effects on the adhesion of the cells to PMMA resin surface.With further testing and development,S.officinalis essential oil may be used as an antifungal denture cleanser to prevent candidal adhesion and thus reduce the risk of candida-associated denture stomatitis.

Enterogenous infection of Candida albicans in immunocompromised rats under severe acute pancreatitis

BACKGROUND:Opportunistic infection of Candida albicans(C.albicans) has become a serious problem in immunocompromised patients.The study aimed to explore the mechanism of enterogenous infection of C.albicans in immunocompromised rats under severe acute pancreatitis(SAP).METHODS:Sprague Dawley(SD) rats(n=100) were randomly assigned into 5 groups as the following:blank group,cyclophosphamide+ceftriaxone+SAP group,cyclophosphamide+ceftriaxone group,cyclophosphamide+SAP group,and cyclophosphamide group.The rats were sacrificed at 5and 10 days,and their jejunum,colon,mesenteric lymph nodes,pancreas,intestinal content,and blood were quickly collected to detect C.albicans.A region of the 25 S rRNA gene was chosen and amplified by polymerase chain reaction(PCR) to differentiate C.albicans genotypes.The amplified products were further sequenced and compared to judge their homology.RESULTS:Compared with the Cyclophosphamide group,the combination of immunosuppressants and broad-spectrum antibiotics significantly increased the colonization of C.albicans in intestine in 5 and 10 days.Pure SAP stress did not increase the opportunistic infection of C.albicans.The PCR products of C.albicans isolates all belonged to the genotype A family,and sequence alignment showed that the amplified fragments were homologous.CONCLUSION:The damage of immune system and broad-spectrum antimicrobial agents are important risk factors for opportunistic fungal infection.Intestinal tract is an important source for genotype-A C.albicans to translocate and invade into bloodstream.

Study of the prevalence and association of ocular chlamydial conjunctivitis in women with genital infection by Chlamydia trachomatis, Mycoplasma genitalium and Candida albicans attending outpatient clinic

AIMTo determine the association between chlamydial conjunctivitis and genital infection by Chlamydia trachomatis, Mycoplasma genitalium and Candida albicans, in addition to the possible relationship between cultured bacterial pathogens and oculogenital chlamydial infection.METHODSThis study was performed on 100 (50 symptomatic and 50 asymptomatic) women attending the Gynecological and Obstetric outpatient clinic of Alzahra hospital, Alazhar University. Simultaneously a conjunctival swab was taken from these patients. Polymerase chain reaction (PCR) was done on DNA extracted from both vaginal and conjunctival swab samples. Culture for both vaginal and conjunctival swabs was also done.RESULTSCandida albicans was the predominant organism isolated by culture in 20% and 40% of conjunctival and vaginal swabs respectively. By the PCR method, ocular Chlamydia trachomatis was present in 60% of symptomatic women, while genital Chlamydia trachomatis infection was present in 30% of symptomatic women. The results of this method also indicated that 25/50 (50%) vaginal swabs were positive with PCR for Candida albicans versus 15/50 (30%) were PCR positive in conjunctival swab. Mycoplasma genitalium was present in only 10% of vaginal swabs. Concomitant oculogenital PCR positive results for Chlamydia trachomatis and Candida albicans were 30% and 28% respectively.CONCLUSIONOcular Chlamydia trachomatis was associated with genital Chlamydia trachomatis in a high percentage of women followed by Candida albicans. Cultured bacterial organisms do not play a role in enhancement of Chlamydia trachomatis infection.

Biodegradation of 4-Chlorophenol by Candida albicans PDY-07 under Anaerobic Conditions

Candida albicans PDY-07 was isolated from activated sludge under anaerobic conditions and identified as a member belonging to the genus Candida. Pure culture of C. albicans PDY-07, biodegradation of 4-chlorophenol 4-CP was carried out under anaerobic conditions in Erlenmeyer flasks at 35℃, with an initial pH of 7.0—7.2 and a starting inoculum of 10% by volume. The results showed that, under the above-mentioned con- ditions, C. albicans PDY-07 could thoroughly biodegrade 4-CP up to a concentration of 300mg·L-1 within 244h and that it had a high tolerance potential of up to 440mg·L-1 for 4-CP. With the increase in the initial concentrations of 4-CP, substrate inhibition was obviously enhanced. There was increased consumption of 4-CP, which was not assimilated by the cell for growth but was used to counteract the strong substrate inhibition. In addition, the cell growth and substrate-degradation kinetics of 4-CP as the sole source of carbon and energy for the strain in batch cultures were also investigated over a wide range of substrate concentrations 2.2—350mg·L-1, using the proposed cell growth and degradation kinetic models. The results recorded from these experiments showed that the proposed kinetic models adequately described the dynamic behavior of 4-CP biodegradation by C. albicans PDY-07.

Antifungal susceptibility analysis of berberine,baicalin,eugenol and curcumin on Candida albicans

Objective:To analyze the antifungal effects of Chinese herb monomers,i.e.berberine,baicalin,eugenol and curcumin,on Candida albicans.Methods:After Candida albicans strain Y01-09 was incubated for 48 h in YEPD broth which contained different concentrations of Chinese herb components,the cell cycle,fluorescent intensity and the size of cell volume were detected by flow cytometry.Results:The 4 Chinese herb monomers could affect the cell cycle of Candida albicans in different ranges.The ratio of cells in S-G2-M period decreased as the agents concentration increased,indicating that the cell division was inhibited.The fluorescent intensity of Candida albicans cells became weaker after being incubated,which reflected the loss of DNA fragments.The higher the concentration was,the weaker the fluorescent intensity became.The cell size,cell diopter and particle size changed much as the agents concentration increased.Conclusion:Chinese herb monomers play the antifungal role in inhibiting cell division.FCM could be used to determine the susceptibility of antifungal agents.

Fluconazole Susceptibility and Genotypic Heterogeneity of Oral Candida albicans Colonies from the Patients with Cancer Receiving Chemotherapy in China

Aim To identify heterogeneity of Candida albicans （C. albicans） isolated from the population with cancer in China by using identification medium, subculture molecular typing, and antifungal susceptibility test. Methodology Oral cheek mucosal specimens from 52 cancer patients receiving chemotherapy were cultured on CHROMagar CandidaTM plates for Candida identification. All the C. albicans colonies on the plates were subcultured and reconfirmed by API20C, then submitted to the antifimgal drug susceptibility test with fluconazole and molecular typing using randomly amplified polymorphic DNA-PCR （RAPD） with primers RSD6 and RSD12.Results 54% （28/52） patients were oral yeast carriage in which C. albicans predominated. More than 7 C. albicans colonies were isolated from each of 12 patients （Group A）, while less than 5 colonies were isolated from each of 16 patients （Group B）. RSD6 and RSD12 were successful in eliciting 17 （A1-A17） and 2 （B1-B2） genotypes, respectively from among the 205 isolates. The two primers were combined to generate 21 genotypes. The C. albicans isolates obtained from the same patient and episode showed a diversity for fluconazole revealed by MIC50 and MIC90. Conclusion The heterogeneity of the C. albicans colonies isolated from the same patients can be detected. C. albicans with varied fluconazole susceptibility and genotypic characteristics may coexist in the same oral Candida population.

Study of Candida Albicans Vaginitis Model in Kunming Mice

The model of vaginal candidiasis in Kunming mice was constructed in order to search for the optima construction conditions and provide an economic animal model of Candida albicans (C. albicans) vaginitis. Estrogen benzoate (E2) was given to mice at different concentrations ranging from 0.0 to 0.05 mg/mouse (4 levels) beginning 72 h prior to vaginal inoculation, then mice were in- oculated intravaginally with various concentrations of stationary-phase C. albicans blastoconidia (ATCC90028) (5 levels) in 20 μL of phosphate-buffered saline (PBS) in each E2 level. General state, scores of genital pathology, the hyphae and vaginal fungal burden (CFU) in vaginal lavage fluid, the hydrops rate of uterus and vaginal tissues for pathological section in mice were observed and ob- tained at day 2, 4, 7, 14 and 21 after inoculation. The results showed the infection rate in mice was related to the dosage of E2 and concentration of C. albicans blastoconidia. Additionally there was better cross-effect between the two treated factors. The infection rate was about 80% on the day 4, and could reach 100% on the day 7 until the end of experiment after inoculated intravaginally in groups of E2I3, E2 0.025 mg/mouse injected hypodermically and inoculated intravaginally with 5×104 C. albicans blastoconidia, and large amount of hyphae and blastoconidia could be observe in superfi- cial layer tissue and canal of vaginal by PAS. From the results in our experiment it was concluded that E2I3 was the optima construction condition in kunming mice.

Comparison of the Effects of Three Different Anti-fungus Drugs on Candida Albicans of Murine Vaginal Mucosa

To compare the therapeutic effects of three different anti-fungal drugs （i.e., terbinafine, fluconazole and intraconazole） in the treatment of experimental vaginitis caused by Candida albicans （C. albicans） in mice, the fungal vaginitis model was established in female ICR mice by intravaginal inoculation of suspension of C. albicans after the animal had been pretreated with estradiol. Mice were divided at random into different groups and then respectively treated with terbinafine, fluconazole and intraconazole given by gastrogavage. The burden of the fungus in the vaginal lavage fluids in the mice of the different groups was measured dynamically at different time points after the beginning of the drug treatment. The fungal burdens in the vaginal lavage fluids taken at different time points from the mice treated with terbinafine were significantly higher than those taken at corresponding time points from mice treated with fluconazole or itraconazole （P〈0.01）. The fungal burdens in the vaginal lavage fluids taken from mice 1 week after the beginning of the treatment with terbinafine remained at a relatively high level. A dramatic drop in the fungal burden was noted in the vaginal lavage fluids taken on the 2nd day of the treatment from mice treated with itraconazole or fluconazole group and the fungal burden on the 3rd day of the treatment in these mice were at a very low level, suggesting that fluconazole or itraconazole were highly effective for the treatment. However, the difference in the therapeutic effect between the two drugs was not significant （P〉0.05）. Itraconazole or fluconazole, but not terbinafine, is very effective for the treatment of fungal vaginitis caused by C. albicans in mice.

HIV aspartyl protease inhibitors as promising compounds against Candida albicans

Cells of Candida albicans(C.albicans) can invade humans and may lead to mucosal and skin infections or to deep-seated my coses of almost all inner organs,especially in immunocompromised patients.In this context,both the host immune status and the ability of C.albicans to modulate the expression of its virulence factors are relevant aspects that drive the candidal susceptibility or resistance;in this last case,culminating in the establishment of successful infection knownas candidiasis.C.albicans possesses a potent arma-mentarium consisting of several virulence moleculesthat help the fungal cells to escape of the host immuneresponses.There is no doubt that the secretion of aspartyl-type proteases,designated as Saps,are one of the major virulence attributes produced by C.albicans cells,since these hydrolytic enzymes participate in a wide range of fungal physiological processes as well as in different facets of the fungal-host interactions.For these reasons,Saps clearly hold promise as new potential drug targets.Corroborating this hypothesis,the introduction of new anti-human immunodeficiency virus drugs of the as party l protease inhibitor-type(HIV PIs) have emerged as new agents for the inhibition of Saps.The introduction of HIV PIs has revolutionized the treatment of HIV disease,reducing opportunistic infections,especially candidiasis.The attenuation of candidal infections in HIV-infected individuals might not solely have resulted from improved immunological status,but also as a result of direct inhibition of C.albicans Saps.In this article,we review updates on the beneficial effects of HIV PIs against the human fungal pathogen C.albicans,focusing on the effects of these compounds on Sap activity,growth behavior,morphological architecture,cellular differentiation,fungal adhesion to animal cells and abiotic materials,modulation of virulence factors,experimental candidiasis infection,and their synergistic actions with classical antifungal agents.

白假丝酵母菌(Candida albicans)WO-1分泌蛋白质组的生物信息学分析

为了获得白假丝酵母菌WO-1的完整分泌蛋白质组及其生物学信息,采用分析软件SignalP v 4.1、TMHMM server v 2.0、Phobius、TargetP 1.1及Big-PI Fungal Predictor v 3.1,对白假丝酵母菌WO-1全基因组6170个ORFs进行分泌蛋白预测和解析。结果表明,白假丝酵母菌WO-1的预测分泌蛋白质组共包含216个蛋白质,信号肽切割位点前后-3^+3氨基酸组成丙氨酸(A)最多,切割位点相对不保守;31.90%的分泌蛋白已明确注释了细胞外定位,33.33%并无明确的细胞分布定位;预测的分泌蛋白共检索到生物学功能124个,其中具有水解酶活性的蛋白最多,占11.57%,同时存在40.28%的预测蛋白未注释明确的生物学功能。因此,分泌蛋白参与了白假丝酵母菌多种核心致病过程,分泌蛋白质组的获得将为揭示白假丝酵母菌WO-1的致病机理提供更加完备的参考。

Prevalence of Non-<i>Albicans Candida</i>Infections in Women with Recurrent Vulvovaginal Symptomatology

Background: Candida vulvovaginitis is one of the most frequently diagnosed conditions in women’s care practices. Historically, 90% of cultured yeast species were C. albicans. However, due to a variety of interventions, the proportion of non-albicans Candida (NAC) infections appears to be increasing. We sought to estimate the current prevalence of Candida vulvovaginitis and the species-specific distribution of such infections in recurrent cases. Methods: Women with recurrent vulvovaginal symptomatology referred to an Obstetrics and Gynecology practice were tested by genital fungus culture, Candida-specific polymerase chain reaction (PCR), or both between July 2010 and February 2013. Results: A total of 103 women were tested. Mean age was 45.6 years. Including only their most recent positive test result, 29.1% (30/103) of women tested positive for Candida by any of the above testing measures. Of those, 50% (15/30) tested positive for C. albicans and 50% (15/30) tested positive for a NAC species. Across all visits, 60% (18/30) tested positive for C. albicans, 56.7% (17/30) tested positive for NAC, and 16.7% (5/30) tested positive for both a C. albicans and a NAC species. Among all isolated NAC species, 28.6% (6/21) were determined to be C. glabrata, 23.8% (5/21) C. krusei, 23.8% (5/21) C. parapsilosis, and 23.8% (5/21) other Candida species. Conclusion: Approximately 30% of women with recurrent vulvovaginal symptomatology have detectable Candida strains and it appears that NAC species may cause half of all these infections. This is imperative because NAC infections are usually more difficult to diagnose and are resistant to most treatments.

Non-albicans Candida prosthetic joint infections: A systematic review of treatment

BACKGROUND Non-albicans Candida prosthetic joint infections (PJIs) are rare. Optimal treatment involves a two-stage revision surgery in combination with an antifungal agent. However, no clear guidelines have been developed regarding the agent or treatment duration. Hence, a broad range of antifungal and surgical treatments have been reported so far. AIM To clarify treatment of non-albicans Candida PJIs. METHODS A literature review of all existing non-albicans Candida PJIs cases through April 2018 was conducted. Information was extracted about demographics, comorbidities, responsible species, duration and type of antifungal treatment, type of surgical treatment, time between initial arthroplasty and symptom onset, time between symptom onset and definite diagnosis, outcome of the infection and follow-up. RESULTS A total of 83 cases, with a mean age of 66.3 years, were located. The causative yeast isolated in most cases was C. parapsilosis (45 cases;54.2%), followed by C. glabrata (18 cases;21.7%). The mean Charlson comorbidity index was 4.4 ± 1.5. The mean time from arthropalsty to symptom onset was 27.2 ± 43 mo, while the mean time from symptom onset to culture-confirmed diagnosis was 7.5 ± 12.5 mo. A two stage revision arthroplasty (TSRA), when compared to one stage revision arthroplasty, had a higher success rate (96% vs 73%, P = 0.023). Fluconazole was the preferred antifungal agent (59;71%), followed by amphotericin B (41;49.4%). CONCLUSION The combination of TSRA and administration of prolonged antifungal therapy after initial resection arthroplasty is suggested on the basis of limited data.

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.

ERG11 mutations associated with azole resistance in Candida albicans isolates from vulvovaginal candidosis patients

Objective: To investigate the azole susceptibility of Candida albicans(C.albicans)from vulvovaginal candidosis patients and to analyze the relationship between ERG11 gene mutations in these isolates and azole resistance.Methods: Three hundred and two clinical isolates of Candida species were collected.Azole susceptibility was tested in vitro in microdilution studies. The ERG11 genes of 17 isolates of C. albicans(2 susceptibles, 5 dose-dependent resistants and 10 resistants) were amplified and sequenced.Results: Of the 302 isolates collected, 70.2% were C. albicans, of which 8.5%, 3.8% and4.2% were resistant to fluconazole, itraconazole and voriconazole, respectively. In total,27 missense mutations were detected in ERG11 genes from resistant/susceptible dosedependent isolates. Among them, Y132 H, A114 S, and Y257 H substitutions were most prevalent and were known to cause fluconazole resistance. G464 S and F72 S also have been proved to cause fluconazole resistance. Two novel substitutions(T285A, S457P) in hotspot regions were identified.Conclusions: Twenty seven mutations in the ERG11 gene were identified in azoleresistant C. albicans isolates, which indicated a possible relation with the increase in resistance to azole drugs and the recurrence of vulvovaginal candidosis. The relationship of two novel substitutions(T285A, S457P) with fluconazole resistance needs to be further verified by site-directed mutagenesis.