Displaying publications 61 - 80 of 273 in total

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  1. Enhanced toluene removal using granular activated carbon and a yeast strain Candida tropicalis in bubble-column bioreactors
    Ahmed Z, Hwang SJ, Shin SK, Song J
    J Hazard Mater, 2010 Apr 15;176(1-3):849-55.
    PMID: 20031312 DOI: 10.1016/j.jhazmat.2009.11.114
    The yeast strain Candida tropicalis was used for the biodegradation of gaseous toluene. Toluene was effectively treated by a liquid culture of C. tropicalis in a bubble-column bioreactor, and the toluene removal efficiency increased with decreasing gas flow rate. However, toluene mass transfer from the gas-to-liquid phase was a major limitation for the uptake of toluene by C. tropicalis. The toluene removal efficiency was enhanced when granular activated carbon (GAC) was added as a fluidized material. The GAC fluidized bioreactor demonstrated toluene removal efficiencies ranging from 50 to 82% when the inlet toluene loading was varied between 13.1 and 26.9 g/m(3)/h. The yield value of C. tropicalis ranged from 0.11 to 0.21 g-biomass/g-toluene, which was substantially lower than yield values for bacteria reported in the literature. The maximum elimination capacity determined in the GAC fluidized bioreactor was 172 g/m(3)/h at a toluene loading of 291 g/m(3)/h. Transient loading experiments revealed that approximately 50% of the toluene introduced was initially adsorbed onto the GAC during an increased loading period, and then slowly desorbed and became available to the yeast culture. Hence, the fluidized GAC mediated in improving the gas-to-liquid mass transfer of toluene, resulting in a high toluene removal capacity. Consequently, the GAC bubble-column bioreactor using the culture of C. tropicalis can be successfully applied for the removal of gaseous toluene.
    Matched MeSH terms: Candida tropicalis/metabolism*
  2. Immobilization of lipase from Candida rugosa on layered double hydroxides for esterification reaction
    Rahman MB, Basri M, Hussein MZ, Rahman RN, Zainol DH, Salleh AB
    Appl Biochem Biotechnol, 2004 8 12;118(1-3):313-20.
    PMID: 15304759
    Synthesis of layered double hydroxides (LDHs) of Zn/Al-NO3- hydrotalcite (HIZAN) and Zn/Al-diocytyl sodium sulfosuccinate (DSS) nanocomposite (NAZAD) with a molar ratio of Zn/Al of 4:1 were carried out by coprecipitation through continuous agitation. Their structures were determined using X-ray diffractometer spectra, which showed that basal spacing for LDH synthesized by both methods was about 8.89 A. An expansion of layered structure of about 27.9 A was observed to accommodate the surfactant anion between the interlayer. This phenomenon showed that the intercalation process took place between the LDH interlayer. Lipase from Candida rugosa was immobilized onto these materials by physical adsorption method. It was found that the protein loading onto NAZAD is higher than HIZAN. The activity of immobilized lipase was investigated through esterification of oleic acid and 1-butanol in hexane. The effects of pore size, surface area, reaction temperature, thermostability of the immobilized lipases, storage stability in organic solvent, and leaching studies were investigated. Stability was found to be the highest in the nanocomposite NAZAD.
    Matched MeSH terms: Candida/enzymology*
  3. Pathogenic microbes of the oral environment
    Park AW, Yaacob HB
    J Nihon Univ Sch Dent, 1994 Mar;36(1):1-33.
    PMID: 8207501
    Matched MeSH terms: Candida/pathogenicity
  4. The effect of water activity on modified lipase during esterification
    Salleh AB, Taib M, Basri M, Ampon K, Yunus WM, Razak CN
    Ann N Y Acad Sci, 1996 Oct 12;799:328-31.
    PMID: 8958097
    Matched MeSH terms: Candida/enzymology*
  5. Water activity effect on lipase immobilized onto different compositions of poly(HEMA-MMA)
    Esa NM, Yunus WM, Ahmad MB, Basri M, Razak CN, Salleh AB
    Ann N Y Acad Sci, 1998 Dec 13;864:489-92.
    PMID: 9928130
    Matched MeSH terms: Candida/enzymology
  6. Reductive alkylation of lipase: experimental and molecular modeling approaches
    Rahman RN, Tejo BA, Basri M, Rahman MB, Khan F, Zain SM, et al.
    Appl Biochem Biotechnol, 2004 8 12;118(1-3):11-20.
    PMID: 15304735
    Candida rugosa lipase was modified via reductive alkylation to increase its hydrophobicity to work better in organic solvents. The free amino group of lysines was alkylated using propionaldehyde with different degrees of modification obtained (49 and 86%). Far-ultraviolet circular dichroism (CD) spectroscopy of the lipase in aqueous solvent showed that such chemical modifications at the enzyme surface caused a loss in secondary and tertiary structure that is attributed to the enzyme unfolding. Using molecular modeling, we propose that in an aqueous environment the loss in protein structure of the modified lipase is owing to disruption of stabilizing salt bridges, particularly of surface lysines. Indeed, molecular modeling and simulation of a salt bridge formed by Lys-75 to Asp-79, in a nonpolar environment, suggests the adoption of a more flexible alkylated lysine that may explain higher lipase activity in organic solvents on alkylation.
    Matched MeSH terms: Candida/enzymology
  7. Fulltext Epidemiology and outcomes of candidaemia among adult patients admitted at Hospital Universiti Sains Malaysia (HUSM): a 5-year review
    Haydar, A.
    International Medical Journal Malaysia, 2018;17(1):3-12.
    MyJurnal
    Candida organisms are opportunistic fungal pathogens that have become a major cause of nosocomial infections worldwide. We investigated the clinical characteristics and outcomes of hospitalized patients with candidaemia caused by Candida albicans and non-albicans Candida spp at HUSM. Materials and Methods: We retrospectively evaluated all hospitalized patients with candidaemia from January 2010 till December 2014 based on inpatient hospital records and laboratory data. Results: A total of 134 patients with candidaemia were enrolled. Candida albicans and non-albicans Candida spp were responsible for 20% (27/134) and 80% (107/134) of candidaemia cases, respectively. Hospitalized patients with diabetes mellitus, surgical conditions, or concomitant septicaemia and those who received instrumentations such as CVC or CBD, and those admitted under medical settings were prone to develop candidaemia caused by either C. albicans or non-albicans Candida spp. All isolates were susceptible to Fluconazole except for C. krusei isolates. All-cause mortality within 30 days post diagnosis of candidaemia was 59%. Factors associated with mortality were solid tumor (p =0.014), surgical illness (p=0.128), central venous catheterization (p= 0.096) and leucocytosis (p=0.116). Only solid tumor was an independent contributory factor for mortality among patients with C. albicans candidaemia in the multivariate analyses (OR 5.09, 95% CI 1.38,18.74, p=0.014). Conclusions: The patients’ clinical characteristics were fairly comparable between Candida albicans and non-albicans candidaemia. The changing epidemiology of candidaemia at this centre was in fact alarming. The outcome associated with candidaemia was poor.
    Matched MeSH terms: Candida; Candida albicans
  8. Quantitative structure-activity relationship model for classifying the diverse series of antifungal agents using ratio weighted penalized logistic regression
    Alharthi AM, Lee MH, Algamal ZY, Al-Fakih AM
    SAR QSAR Environ Res, 2020 Aug;31(8):571-583.
    PMID: 32628042 DOI: 10.1080/1062936X.2020.1782467
    One of the most challenging issues when facing a Quantitative structure-activity relationship (QSAR) classification model is to deal with the descriptor selection. Penalized methods have been adapted and have gained popularity as a key for simultaneously performing descriptor selection and QSAR classification model estimation. However, penalized methods have drawbacks such as having biases and inconsistencies that make they lack the oracle properties. This paper proposes an adaptive penalized logistic regression (APLR) to overcome these drawbacks. This is done by employing a ratio (BWR) of the descriptors between-groups sum of squares (BSS) to the within-groups sum of squares (WSS) for each descriptor as a weight inside the L1-norm. The proposed method was applied to one dataset that consists of a diverse series of antimicrobial agents with their respective bioactivities against Candida albicans. By experimental study, it has been shown that the proposed method (APLR) was more efficient in the selection of descriptors and classification accuracy than the other competitive methods that could be used in developing QSAR classification models. Another dataset was also successfully experienced. Therefore, it can be concluded that the APLR method had significant impact on QSAR analysis and studies.
    Matched MeSH terms: Candida albicans/drug effects*
  9. Therapeutic efficacy of adjunctive photodynamic therapy in the treatment of denture stomatitis
    Al-Ghamdi ARS, Khanam HK, Qamar Z, Abdul NS, Reddy N, Vempalli S, et al.
    Photodiagnosis Photodyn Ther, 2023 Jun;42:103326.
    PMID: 36773753 DOI: 10.1016/j.pdpdt.2023.103326
    BACKGROUND: The present report assessed the efficacy of curcumin-mediated photodynamic therapy (CUR-mediated PDT) as an adjunct to antifungal gel treatment by evaluating the salivary interleukin-6 (IL-6) and matrix metalloproteinases-8 (MMP-8) levels together with Candida species counts in denture stomatitis (DS) patients.

    METHODS: In total, 50 DS subjects were randomly categorized into 2 groups: Group-1: subjects who received the antifungal gel treatment and Group-2: participants who received CUR-mediated PDT. The Sabourad Dextrose Agar and CHROMAgar were utilized for evaluating Candida species counts, while the Enzyme-Linked Immunosorbent Assay was employed to estimate the salivary levels of IL-6 and MMP-8. All clinical evaluations were performed at the baseline, 1 month, and 2 months.

    RESULTS: In total, group-2 subjects showed a significant decrease in Candida albicans (C. albicans) counts on both follow-ups (i.e., 1-month and 2-month) than group-1 participants. C. krusei count also reduced in group-2 subejcts than group-1 participants at the 2nd follow-up as compared to the baseline, nevertheless, a slight increase in C. krusei count was noticed in group-2 subjects at the 2nd follow-up than the 1st follow-up. The salivary IL-6 and MMP-8 levels in both groups reduced significantly at both follow-ups than the baseline. According to the stepwise logistic regression analysis, no statistically significant correlation was observed between Candida species count and other parameters such as age and gender of the patient, duration of DS, and frequency of treatment(s).

    CONCLUSION: CUR-mediated PDT is an efficaciousness therapeutic modality for alleviating Candida species counts on the surface of denture and the palatal mucosa, as well as improving the salivary IL-6 and MMP-8 levels in DS patients.

    Matched MeSH terms: Candida; Candida albicans
  10. Fulltext Transcriptomic and proteomic profiling revealed reprogramming of carbon metabolism in acetate-grown human pathogen Candida glabrata
    Chew SY, Brown AJP, Lau BYC, Cheah YK, Ho KL, Sandai D, et al.
    J Biomed Sci, 2021 Jan 02;28(1):1.
    PMID: 33388061 DOI: 10.1186/s12929-020-00700-8
    BACKGROUND: Emergence of Candida glabrata, which causes potential life-threatening invasive candidiasis, has been widely associated with high morbidity and mortality. In order to cause disease in vivo, a robust and highly efficient metabolic adaptation is crucial for the survival of this fungal pathogen in human host. In fact, reprogramming of the carbon metabolism is believed to be indispensable for phagocytosed C. glabrata within glucose deprivation condition during infection.

    METHODS: In this study, the metabolic responses of C. glabrata under acetate growth condition was explored using high-throughput transcriptomic and proteomic approaches.

    RESULTS: Collectively, a total of 1482 transcripts (26.96%) and 242 proteins (24.69%) were significantly up- or down-regulated. Both transcriptome and proteome data revealed that the regulation of alternative carbon metabolism in C. glabrata resembled other fungal pathogens such as Candida albicans and Cryptococcus neoformans, with up-regulation of many proteins and transcripts from the glyoxylate cycle and gluconeogenesis, namely isocitrate lyase (ICL1), malate synthase (MLS1), phosphoenolpyruvate carboxykinase (PCK1) and fructose 1,6-biphosphatase (FBP1). In the absence of glucose, C. glabrata shifted its metabolism from glucose catabolism to anabolism of glucose intermediates from the available carbon source. This observation essentially suggests that the glyoxylate cycle and gluconeogenesis are potentially critical for the survival of phagocytosed C. glabrata within the glucose-deficient macrophages.

    CONCLUSION: Here, we presented the first global metabolic responses of C. glabrata to alternative carbon source using transcriptomic and proteomic approaches. These findings implicated that reprogramming of the alternative carbon metabolism during glucose deprivation could enhance the survival and persistence of C. glabrata within the host.

    Matched MeSH terms: Candida glabrata/metabolism*
  11. Bibliometric analysis and thematic review of Candida pathogenesis: Fundamental omics to applications as potential antifungal drugs and vaccines
    Lim SJ, Muhd Noor ND, Sabri S, Mohamad Ali MS, Salleh AB, Oslan SN
    Med Mycol, 2024 Jan 09;62(1).
    PMID: 38061839 DOI: 10.1093/mmy/myad126
    Invasive candidiasis caused by the pathogenic Candida yeast species has resulted in elevating global mortality. The pathogenicity of Candida spp. is not only originated from its primary invasive yeast-to-hyphal transition; virulence factors (transcription factors, adhesins, invasins, and enzymes), biofilm, antifungal drug resistance, stress tolerance, and metabolic adaptation have also contributed to a greater clinical burden. However, the current research theme in fungal pathogenicity could hardly be delineated with the increasing research output. Therefore, our study analysed the research trends in Candida pathogenesis over the past 37 years via a bibliometric approach against the Scopus and Web of Science databases. Based on the 3993 unique documents retrieved, significant international collaborations among researchers were observed, especially between Germany (Bernhard Hube) and the UK (Julian Naglik), whose focuses are on Candida proteinases, adhesins, and candidalysin. The prominent researchers (Neils Gow, Alistair Brown, and Frank Odds) at the University of Exeter and the University of Aberdeen (second top performing affiliation) UK contribute significantly to the mechanisms of Candida adaptation, tolerance, and stress response. However, the science mapping of co-citation analysis performed herein could not identify a hub representative of subsequent work since the clusters were semi-redundant. The co-word analysis that was otherwise adopted, revealed three research clusters; the cluster-based thematic analyses indicated the severeness of Candida biofilm and antifungal resistance as well as the elevating trend on molecular mechanism elucidation for drug screening and repurposing. Importantly, the in vivo pathogen adaptation and interactions with hosts are crucial for potential vaccine development.
    Matched MeSH terms: Candida/genetics
  12. Fulltext Assessment of Antifungal Activity of Bakuchiol on Oral-Associated Candida spp
    Nordin MA, Abdul Razak F, Himratul-Aznita WH
    Evid Based Complement Alternat Med, 2015;2015:918624.
    PMID: 26633986 DOI: 10.1155/2015/918624
    Bakuchiol is an active component of Psoralea glandulosa and Psoralea corylifolia, used in traditional Chinese medicine. The study aimed at investigating the antifungal activity of bakuchiol on planktonic and biofilm forms of orally associated Candida species. The antifungal susceptibility testing was determined by the broth micro dilution technique. Growth kinetics and cell surface hydrophobicity (CSH) of Candida were measured to assess the inhibitory effect of bakuchiol on Candida planktonic cells. Biofilm biomass and cellular metabolic activity were quantitatively estimated by the crystal violet (CV) and the 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide (XTT) assays. All Candida strains have been shown to be susceptible to bakuchiol with the MIC ranges from 12.5 to 100 μg/mL. Significant decrease in specific growth rates and viable counts demonstrates the inhibitory effect of bakuchiol on Candida planktonic cells. A brief exposure to bakuchiol also reduced CSH of Candida (P < 0.05), indicating altered surface properties of yeast cells towards hydrophobic interfaces. Biofilm biomass and cell metabolic activity were mostly decreased, except for C. glabrata (P = 0.29). The antifungal properties of bakuchiol on Candida species in this in vitro study may give insights into the application in therapeutic strategy against Candida infections.
    Matched MeSH terms: Candida; Candida glabrata
  13. In vitro expression of Candida albicans alcohol dehydrogenase genes involved in acetaldehyde metabolism
    Bakri MM, Rich AM, Cannon RD, Holmes AR
    Mol Oral Microbiol, 2015 Feb;30(1):27-38.
    PMID: 24975985 DOI: 10.1111/omi.12064
    Alcohol consumption is a risk factor for oral cancer, possibly via its conversion to acetaldehyde, a known carcinogen. The oral commensal yeast Candida albicans may be one of the agents responsible for this conversion intra-orally. The alcohol dehydrogenase (Adh) family of enzymes are involved in acetaldehyde metabolism in yeast but, for C. albicans it is not known which family member is responsible for the conversion of ethanol to acetaldehyde. In this study we determined the expression of mRNAs from three C. albicans Adh genes (CaADH1, CaADH2 and CaCDH3) for cells grown in different culture media at different growth phases by Northern blot analysis and quantitative reverse transcription polymerase chain reaction. CaADH1 was constitutively expressed under all growth conditions but there was differential expression of CaADH2. CaADH3 expression was not detected. To investigate whether CaAdh1p or CaAdh2p can contribute to alcohol catabolism in C. albicans, each gene from the reference strain C. albicans SC5314 was expressed in Saccharomyces cerevisiae. Cell extracts from an CaAdh1p-expressing S. cerevisiae recombinant, but not an CaAdh2p-expressing recombinant, or an empty vector control strain, possessed ethanol-utilizing Adh activity above endogenous S. cerevisiae activity. Furthermore, expression of C. albicans Adh1p in a recombinant S. cerevisiae strain in which the endogenous ScADH2 gene (known to convert ethanol to acetaldehyde in this yeast) had been deleted, conferred an NAD-dependent ethanol-utilizing, and so acetaldehyde-producing, Adh activity. We conclude that CaAdh1p is the enzyme responsible for ethanol use under in vitro growth conditions, and may contribute to the intra-oral production of acetaldehyde.
    Matched MeSH terms: Candida albicans/enzymology; Candida albicans/genetics*; Candida albicans/growth & development
  14. In vitro and in situ antiyeast activity of Gracilaria changii methanol extract against Candida albicans
    Sasidharan S, Darah I, Jain K
    Eur Rev Med Pharmacol Sci, 2011 Sep;15(9):1020-6.
    PMID: 22013724
    The Gracilaria (G.) sp are widely used in the traditional medicine in Malaysia. The methanol extract of Gracilaria changii B.M. Xia & I.A. Abbott (Gracilariaciae) was evaluated for antiyeast activity against Candida albicans (Berkhout).
    Matched MeSH terms: Candida albicans/drug effects*; Candida albicans/growth & development; Candida albicans/ultrastructure
  15. Molecular identification of Candida orthopsilosis isolated from blood culture
    Yong PV, Chong PP, Lau LY, Yeoh RS, Jamal F
    Mycopathologia, 2008 Feb;165(2):81-7.
    PMID: 18266075 DOI: 10.1007/s11046-007-9086-8
    The incidence of candidemia and invasive candidiasis have increased markedly due to the increasing number of immunocompromised patients. There are five major medically important species of Candida with their frequency of isolation in the diminishing order namely Candida albicans, Candida parapsilosis, Candida tropicalis, Candida glabrata and Candida krusei. In addition, there are numerous other species of Candida which differ in their genetic makeup, virulence properties, drug susceptibilities and sugar assimilation capabilities. In this report, an unusual Candida species was isolated from the blood of two leukaemic patients. Conventional culture and biochemical tests identified the Candida species as C. parapsilosis. Using fungal-specific oligonucleotide primers ITS1 and ITS4, we managed to amplify the ribosomal RNA gene and its internal transcribed spacer region from the genomic DNA of these isolates. The PCR products were then purified and subjected to automated DNA sequencing using BLAST and CLUSTAL sequence analysis identified these isolates to be Candida orthopsilosis. Candida orthopsilosis is a new species recently identified in 2005, being morphologically indistinguishable from C. parapsilosis and was previously classified as a subspecies of C. parapsilosis. This report highlights the importance of complementing traditional culture and biochemical-based identification methods with DNA-based molecular assays such as PCR as the latter is more superior in terms of its discriminatory power and speed.
    Matched MeSH terms: Candida/classification; Candida/genetics*; Candida/isolation & purification*
  16. Genotyping and drug resistance profile of Candida spp. in recurrent and one-off vaginitis, and high association of non-albicans species with non-pregnant status
    Chong PP, Abdul Hadi SR, Lee YL, Phan CL, Tan BC, Ng KP, et al.
    Infect Genet Evol, 2007 Jul;7(4):449-56.
    PMID: 17324639
    Recurrent vulvovaginal candidiasis affects women worldwide and the resistance to azole drugs may be an important factor. The extent of strain-to-strain variation within a species and its relationship to the ability of the organism to colonize the vulvovaginal mucosa is not well established. The aims of this study were to compare: (i) the genotypes of Candida strains in sequential infections in patients with recurrent vaginitis, (ii) the genotypes of strains in patients with only one episode of infection in a period of 1 year and (iii) determine the in vitro antifungal susceptibilities of strains that cause recurrent vaginitis. Fifty-one cultured specimens from six distinct Candida species were genotyped via random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) method using the ERIC1 and ERIC2 primers (ERIC, enterobacterial repetitive intergenic consensus). Statistical analyses allowed three different scenarios to be discerned for recurrent cases: (i) strain maintenance without genetic variation, (ii) strain maintenance with minor genetic variation and (iii) outright strain replacement. The genetic relatedness between strains from patients with recurrent vaginitis and patients with single episode of vaginitis were demonstrated by the dendogramme and the mean pairwise similarity coefficient S(AB) for the intergroup comparison was 0.223. However, intragroup genetic relatedness was slightly higher than intergroup comparison, with mean S(AB) of 0.261 and 0.331 for Groups I and II, respectively. A high proportion of Group I isolates (87.5%) causing recurrent infections were resistant to ketoconazole, whereas 41.7% of these isolates were cross-resistant to both clotrimazole and ketoconazole as shown by the in vitro antifungal susceptibility test, especially for C. glabrata isolates. Pregnancy status of patients displayed a highly significant association with C. albicans species whereas non-albicans species had a markedly higher prevalence in non-pregnant patients (p<0.001). These results may have a profound impact on the management of vaginal candidiasis, especially in recurrent cases.
    Matched MeSH terms: Candida/drug effects; Candida/genetics*; Candida/isolation & purification
  17. Growth, biofilm formation, antifungal susceptibility and oxidative stress resistance of Candida glabrata are affected by different glucose concentrations
    Ng TS, Desa MNM, Sandai D, Chong PP, Than LTL
    Infect Genet Evol, 2016 06;40:331-338.
    PMID: 26358577 DOI: 10.1016/j.meegid.2015.09.004
    Glucose is an important fuel source to support many living organisms. Its importance in the physiological fitness and pathogenicity of Candida glabrata, an emerging human fungal pathogen has not been extensively studied. The present study aimed to investigate the effects of glucose on the growth, biofilm formation, antifungal susceptibility and oxidative stress resistance of C. glabrata. In addition, its effect on the expression of a putative high affinity glucose sensor gene, SNF3 was also investigated. Glucose concentrations were found to exert effects on the physiological responses of C. glabrata. The growth rate of the species correlated positively to the amount of glucose. In addition, low glucose environments were found to induce C. glabrata to form biofilm and resist amphotericin B. Conversely, high glucose environments promoted oxidative stress resistance of C. glabrata. The expression of CgSNF3 was found to be significantly up-regulated in low glucose environments. The expression of SNF3 gene in clinical isolates was found to be higher compared to ATCC laboratory strains in low glucose concentrations, which may explain the better survivability of clinical isolates in the low glucose environment. These observations demonstrated the impact of glucose in directing the physiology and virulence fitness of C. glabrata through the possible modulation by SNF3 as a glucose sensor, which in turn aids the species to adapt, survive and thrive in hostile host environment.
    Matched MeSH terms: Candida glabrata/drug effects*; Candida glabrata/isolation & purification; Candida glabrata/physiology*
  18. Systemic Candida infection in University hospital 1997-1999: the distribution of Candida biotypes and antifungal susceptibility patterns
    Ng KP, Saw TL, Na SL, Soo-Hoo TS
    Mycopathologia, 2001;149(3):141-6.
    PMID: 11307597
    A total of 102 Candida species were isolated from blood cultures from January 1997 to October 1999. Using assimilation of carbohydrate test, 52 (51.0%) of the Candida sp. were identified as C. parapsilosis, 25.5% (26) were C. tropicalis. C. albicans made up 11.8% (12), 6.9% (7) were C. rugosa, 3.8% (4) C. glabrata and 1% (1) C. guilliermondii. No C. dubliniensis was found in the study. In vitro antifungal susceptibility tests showed that all Candida species were sensitive to nystatin, amphotericin B and ketoconazole. Although all isolates remained sensitive to fluconazole, intermediate susceptibility was found in 3 C. rugosa isolates. Antifungal agents with high frequency of resistance were econazole, clotrimazole, miconazole and 5-fluorocytosine. Candida species found to have resistance to these antifungal agents were non-C. albicans.
    Matched MeSH terms: Candida/classification*; Candida/drug effects; Candida/metabolism
  19. Fulltext Physiologically Relevant Alternative Carbon Sources Modulate Biofilm Formation, Cell Wall Architecture, and the Stress and Antifungal Resistance of Candida glabrata
    Chew SY, Ho KL, Cheah YK, Sandai D, Brown AJP, Than LTL
    Int J Mol Sci, 2019 Jun 28;20(13).
    PMID: 31261727 DOI: 10.3390/ijms20133172
    Flexibility in carbon metabolism is pivotal for the survival and propagation of many human fungal pathogens within host niches. Indeed, flexible carbon assimilation enhances pathogenicity and affects the immunogenicity of Candida albicans. Over the last decade, Candida glabrata has emerged as one of the most common and problematic causes of invasive candidiasis. Despite this, the links between carbon metabolism, fitness, and pathogenicity in C. glabrata are largely unexplored. Therefore, this study has investigated the impact of alternative carbon metabolism on the fitness and pathogenic attributes of C. glabrata. We confirm our previous observation that growth on carbon sources other than glucose, namely acetate, lactate, ethanol, or oleate, attenuates both the planktonic and biofilm growth of C. glabrata, but that biofilms are not significantly affected by growth on glycerol. We extend this by showing that C. glabrata cells grown on these alternative carbon sources undergo cell wall remodeling, which reduces the thickness of their β-glucan and chitin inner layer while increasing their outer mannan layer. Furthermore, alternative carbon sources modulated the oxidative stress resistance of C. glabrata as well as the resistance of C. glabrata to an antifungal drug. In short, key fitness and pathogenic attributes of C. glabrata are shown to be dependent on carbon source. This reaffirms the perspective that the nature of the carbon sources available within specific host niches is crucial for C. glabrata pathogenicity during infection.
    Matched MeSH terms: Candida glabrata/drug effects; Candida glabrata/metabolism*; Candida glabrata/physiology
  20. Recurrent candidaemia in a neonate with Hirschsprung's disease: fluconazole resistance and genetic relatedness of eight Candida tropicalis isolates
    Chong PP, Chieng DC, Low LY, Hafeez A, Shamsudin MN, Seow HF, et al.
    J Med Microbiol, 2006 Apr;55(Pt 4):423-428.
    PMID: 16533990 DOI: 10.1099/jmm.0.46045-0
    The incidence of candidaemia among immunocompromised patients in Malaysia is increasing at an alarming rate. Isolation of clinical strains that are resistant to fluconazole has also risen markedly. We report here the repeated isolation of Candida tropicalis from the blood of a neonatal patient with Hirschsprung's disease. In vitro fluconazole susceptibility tests of the eight isolates obtained at different time points showed that seven of the isolates were resistant and one isolate was scored as susceptible dose-dependent. Random amplification of polymorphic DNA fingerprinting of the isolates using three primers and subsequent phylogenetic analysis revealed that these isolates were highly similar strains having minor genetic divergence, with a mean pairwise similarity coefficient of 0.893+/-0.041. The source of the infectious agent was thought to be the central venous catheter, as culture of its tip produced fluconazole-resistant C. tropicalis. This study demonstrates the utility of applying molecular epidemiology techniques to complement traditional mycological culture and drug susceptibility tests for accurate and appropriate management of recurrent candidaemia and highlights the need for newer antifungals that can combat the emergence of fluconazole-resistant C. tropicalis strains.
    Matched MeSH terms: Candida tropicalis/drug effects; Candida tropicalis/genetics*; Candida tropicalis/isolation & purification
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