Displaying publications 1 - 20 of 32 in total

Abstract:
Sort:
  1. Increased expression and hotspot mutations of the multidrug efflux transporter, CDR1 in azole-resistant Candida albicans isolates from vaginitis patients
    Looi CY, D' Silva EC, Seow HF, Rosli R, Ng KP, Chong PP
    FEMS Microbiol Lett, 2005 Aug 15;249(2):283-9.
    PMID: 16006060
    The aims of our research were to investigate the gene expression of the multidrug efflux transporter, CDR1 and the major drug facilitator superfamily transporter, MDR1 gene in azole drug-resistant Candida albicans and Candida glabrata clinical isolates recovered from vaginitis patients; and to identify hotspot mutations that may be present in the C. albicans CaCDR1 gene that could be associated with drug-resistance. The relative expression of the CDR1 and MDR1 transcripts in ketoconazole and clotrimazole-resistant isolates and drug-susceptible ATCC strains were determined by semi-quantitative reverse transcription-polymerase chain reaction. Expression of CaCDR1 transcript was upregulated to varying extents in all three azole-resistant C. albicans isolates studied (1.6-, 3.7- and 3.9-fold) and all three C. glabrata isolates tested (at 1.9-, 2.3- and 2.7-fold). The overexpression level of CaCDR1 in the isolates correlated with the degree of resistance as reflected by the minimum inhibitory concentration (MIC) of the drugs. The messenger RNA for another efflux pump, MDR1, was also overexpressed in one of the azole-resistant C. albicans isolates that overexpressed CDR1. This finding suggests that drug-resistance may involve synergy between energy-dependent drug efflux pumps CDR1p and MDR1p in some but not all isolates. Interestingly, DNA sequence analysis of the promoter region of the CaCDR1 gene revealed several point mutations in the resistant clinical isolates compared to the susceptible isolates at 39, 49 and 151 nucleotides upstream from the ATG start codon. This finding provides new information on point mutations in the promoter region which may be responsible for the overexpression of CDR1 in drug-resistant isolates.
    Matched MeSH terms: Candidiasis/microbiology*
  2. Molecular differentiation and antifungal susceptibilities of Candida parapsilosis isolated from patients with bloodstream infections
    Tay ST, Na SL, Chong J
    J Med Microbiol, 2009 Feb;58(Pt 2):185-191.
    PMID: 19141735 DOI: 10.1099/jmm.0.004242-0
    The genetic heterogeneity and antifungal susceptibility patterns of Candida parapsilosis isolated from blood cultures of patients were investigated in this study. Randomly amplified polymorphic DNA (RAPD) analysis generated 5 unique profiles from 42 isolates. Based on the major DNA fragments of the RAPD profiles, the isolates were identified as RAPD type P1 (29 isolates), P2 (6 isolates), P3 (4 isolates), P4 (2 isolates) and P5 (1 isolate). Sequence analysis of the internal transcribed spacer (ITS) gene of the isolates identified RAPD type P1 as C. parapsilosis, P2 and P3 as Candida orthopsilosis, P4 as Candida metapsilosis, and P5 as Lodderomyces elongisporus. Nucleotide variations in ITS gene sequences of C. orthopsilosis and C. metapsilosis were detected. Antifungal susceptibility testing using Etests showed that all isolates tested in this study were susceptible to amphotericin B, fluconazole, ketoconazole, itraconazole and voriconazole. C. parapsilosis isolates exhibited higher MIC(50) values than those of C. orthopsilosis for all of the drugs tested in this study; however, no significant difference in the MICs for these two Candida species was observed. The fact that C. orthopsilosis and C. metapsilosis were responsible for 23.8 and 4.8 % of the cases attributed to C. parapsilosis bloodstream infections, respectively, indicates the clinical relevance of these newly described yeasts. Further investigations of the ecological niche, mode of transmission and virulence of these species are thus essential.
    Matched MeSH terms: Candidiasis/microbiology*
  3. Fulltext The Antimicrobial efficacy of Elaeis guineensis: characterization, in vitro and in vivo studies
    Vijayarathna S, Zakaria Z, Chen Y, Latha LY, Kanwar JR, Sasidharan S
    Molecules, 2012 Apr 26;17(5):4860-77.
    PMID: 22538489 DOI: 10.3390/molecules17054860
    The urgent need to treat multi-drug resistant pathogenic microorganisms in chronically infected patients has given rise to the development of new antimicrobials from natural resources. We have tested Elaeis guineensis Jacq (Arecaceae) methanol extract against a variety of bacterial, fungal and yeast strains associated with infections. Our studies have demonstrated that E. guineensis exhibits excellent antimicrobial activity in vitro and in vivo against the bacterial and fungal strains tested. A marked inhibitory effect of the E. guineensis extracts was observed against C. albicans whereby E. guineensis extract at ½, 1, or 2 times the MIC significantly inhibited C. albicans growth with a noticeable drop in optical density (OD) of the bacterial culture. This finding confirmed the anticandidal activity of the extract on C. albicans. Imaging using scanning (SEM) and transmission (TEM) electron microscopy was done to determine the major alterations in the microstructure of the extract-treated C. albicans. The main abnormalities noted via SEM and TEM studies were the alteration in morphology of the yeast cells. In vivo antimicrobial activity was studies in mice that had been inoculated with C. albicans and exhibited good anticandidal activity. The authors conclude that the extract may be used as a candidate for the development of anticandidal agent.
    Matched MeSH terms: Candidiasis/microbiology
  4. Occurrence and characterization of Candida nivariensis from a culture collection of Candida glabrata clinical isolates in Malaysia
    Tay ST, Lotfalikhani A, Sabet NS, Ponnampalavanar S, Sulaiman S, Na SL, et al.
    Mycopathologia, 2014 Oct;178(3-4):307-14.
    PMID: 25022264 DOI: 10.1007/s11046-014-9778-9
    BACKGROUND: Candida nivariensis and C. bracarensis have been recently identified as emerging yeast pathogens which are phenotypically indistinguishable from C. glabrata. However, there is little data on the prevalence and antifungal susceptibilities of these species.

    OBJECTIVE: This study investigated the occurrence of C. nivariensis and C. bracarensis in a culture collection of 185 C. glabrata isolates at a Malaysian teaching hospital.

    METHODS: C. nivariensis was discriminated from C. glabrata using a PCR assay as described by Enache-Angoulvant et al. (J Clin Microbiol 49:3375-9, 2011). The identity of the isolates was confirmed by sequence analysis of the D1D2 domain and internal transcribed spacer region of the yeasts. The isolates were cultured on Chromogenic CHROMagar Candida (®) agar (Difco, USA), and their biochemical and enzymic profiles were determined. Antifungal susceptibilities of the isolates against amphotericin B, fluconazole, voriconazole and caspofungin were determined using E tests. Clotrimazole MICs were determined using a microbroth dilution method.

    RESULTS: There was a low prevalence (1.1 %) of C. nivariensis in our culture collection of C. glabrata. C. nivariensis was isolated from a blood culture and vaginal swab of two patients. C. nivariensis grew as white colonies on Chromogenic agar and demonstrated few positive reactions using biochemical tests. Enzymatic profiles of the C. nivariensis isolates were similar to that of C. glabrata. The isolates were susceptible to amphotericin B, fluconazole, voriconazole and caspofungin. Clotrimazole resistance is suspected in one isolate.

    CONCLUSION: This study reports for the first time the emergence of C. nivariensis in our clinical setting.

    Matched MeSH terms: Candidiasis/microbiology*
  5. Purification and comparison of intracellular proteinase A in Candida spp. isolates from Malaysian and Iranian patients and infected mice
    Amri Saroukolaei S, Pei Pei C, Shokri H, Asadi F
    J Mycol Med, 2012 Jun;22(2):149-59.
    PMID: 23518017 DOI: 10.1016/j.mycmed.2012.01.002
    To compare the specific intracellular proteinase A activity in clinical isolates of Candida species isolated from Iranian and Malaysian patients, the blood and kidneys of mice infected by Candida cells isolated from these human patients.
    Matched MeSH terms: Candidiasis/microbiology*
  6. Onychomycosis in Malaysia
    Ng KP, Saw TL, Madasamy M, Soo Hoo T
    Mycopathologia, 1999;147(1):29-32.
    PMID: 10872513
    The common etiological agents of onychomycosis are dermatophytes, molds and yeasts. A mycological nail investigation of onychomycosis using direct microscopy and culture was conducted by the Mycology Unit, Department of Medical Microbiology, University of Malaya from March 1996 to November 1998. The study involved 878 nail clippings or subungal scrapings from subjects with onychomycosis. On direct microscopy examination, 50% of the specimens were negative for fungal elements. On culture, 373 specimens had no growth; bacteria were isolated from 15 nail specimens. Among the 490 specimens with positive fungal cultures, 177 (36.1%) were dermatophytes, 173 (35.5%) were molds and 130 (26.5%) were Candida. There were 2% (10/490) mixed infections of molds, yeasts and dermatophytes. Trichophyton rubrum (115/177) and Trichophyton mentagrophytes (59/177) were the main dermatophytes isolated. The molds isolated were predominantly Aspergillus niger (61/173), Aspergillus nidulans (30/173), Hendersonula toruloidea (26/173) and Fusarium species (16/173). 96.9% of the Candida species identified were Candida albicans.
    Matched MeSH terms: Candidiasis/microbiology*
  7. Severe infections in systemic lupus erythematosus: disease pattern and predictors of infection-related mortality
    Teh CL, Wan SA, Ling GR
    Clin Rheumatol, 2018 Aug;37(8):2081-2086.
    PMID: 29667100 DOI: 10.1007/s10067-018-4102-6
    Infection is a major cause of morbidity and mortality among patients with systemic lupus erythematosus (SLE). To describe the pattern of serious infections in patients with SLE and to identify the predictors of infection-related mortality among SLE patients with serious infections, we prospectively studied all SLE patients who were hospitalized with infections in Sarawak General Hospital during 2011-2015. Demographic data, clinical features, and outcomes were collected. Cox regression analysis was carried out to determine the independent predictors of infection-related mortality. There were a total of 125 patients with 187 episodes of serious infections. Our patients were of multiethnic origins with female predominance (89.6%). Their mean age was 33.4 ± 14.2 years. The patients had a mean disease duration of 66.8 ± 74.0 months. The most common site of infection was pulmonary (37.9%), followed by septicemia (22.5%). Gram-negative organisms (38.2%) were the predominant isolates within the cohort. There were 21 deaths (11.2%) during the study period. Independent predictors of infection-related mortality among our cohort of SLE patients were flare of SLE (HR 3.98, CI 1.30-12.21) and the presence of bacteremia (HR 2.54, CI 0.98-6.59). Hydroxychloroquine was protective of mortality from serious infections (HR 9.26, CI 3.40-25.64). Pneumonia and Gram-negative organisms were the predominant pattern of infection in our SLE cohort. The presence of flare of SLE and bacteremia were independent prognostic predictors of infection-related mortality, whereas hydroxychloroquine was protective of infection-related mortality among SLE patients with serious infections.
    Matched MeSH terms: Candidiasis/microbiology
  8. Fulltext Endophytic Diaporthe sp. ED2 Produces a Novel Anti-Candidal Ketone Derivative
    Tong WY, Leong CR, Tan WN, Khairuddean M, Zakaria L, Ibrahim D
    J Microbiol Biotechnol, 2017 Jun 28;27(6):1065-1070.
    PMID: 28297749 DOI: 10.4014/jmb.1612.12009
    This study aimed to examine the anti-candidal efficacy of a novel ketone derivative isolated from Diaporthe sp. ED2, an endophytic fungus residing in medicinal herb Orthosiphon stamieus Benth. The ethyl acetate extract of the fungal culture was separated by open column and reverse phase high-performance liquid chromatography (HPLC). The eluent at retention time 5.64 min in the HPLC system was the only compound that exhibited anti-candidal activity on Kirby-Bauer assay. The structure of the compound was also elucidated by nuclear magnetic resonance and spectroscopy techniques. The purified anti-candidal compound was obtainedas a colorless solid and characterized as 3-hydroxy-5-methoxyhex-5-ene-2,4-dione. On broth microdilution assay, the compound also exhibited fungicidal activity on a clinical strain of Candida albicans at a minimal inhibitory concentration of 3.1 μg/ml. The killing kinetic analysis also revealed that the compound was fungicidal against C. albicans in a concentration- and time-dependent manner. The compound was heat-stable up to 70°C, but its anti-candidal activity was affected at pH 2.
    Matched MeSH terms: Candidiasis/microbiology
  9. A modified in situ RT-PCR method for localizing fungal-specific gene expression in Candida-infected mice renal cells
    Yong VC, Ong KW, Sidik SM, Rosli R, Chong PP
    J Microbiol Methods, 2009 Nov;79(2):242-5.
    PMID: 19737582 DOI: 10.1016/j.mimet.2009.08.019
    In situ Reverse Transcriptase PCR (in situ RT-PCR) can amplify mRNA and localize gene expression in cells. However, this method is not feasible in fungi as the thick fungal cell wall constitutes a barrier to this procedure. We developed a two step in situ RT-PCR procedure which enabled the detection and localization of Candida tropicalis mRNA expression in formalin-fixed, paraffin-embedded (FFPE) mouse kidney sections. This in situ hybridization study revealed the first direct evidence for deposition of Candida tropicalis secreted aspartic proteinase 2 (CtSAP2) in the tip of pseudohyphae and its involvement in acute systemic candidiasis. We conclude that in situ RT-PCR can be successfully applied to FFPE tissues and will offer new perspectives in studying gene expression in Candida species.
    Matched MeSH terms: Candidiasis/microbiology*
  10. 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: Candidiasis/microbiology
  11. Purification and comparison of heat shock protein 90 (Hsp90) in Candida albicans isolates from Malaysian and Iranian patients and infected mice
    Khalili V, Shokri H, Khosravi AR, Akim A, Amri Saroukolaei S
    J Mycol Med, 2016 Jun;26(2):94-102.
    PMID: 26869383 DOI: 10.1016/j.mycmed.2015.12.007
    OBJECTIVE: The purposes of this study were to purify and compare the concentration ratios of heat shock protein 90 (Hsp90) in clinical isolates of Candida albicans (C. albicans) obtained from Malaysian and Iranian patients and infected mice.

    MATERIALS AND METHODS: Hsp90 was extracted using glass beads and ultracentrifugation from yeast cells and purified by ion exchange chromatography (DEAE-cellulose) and followed by affinity chromatography (hydroxyapatite). Purity of Hsp90 was controlled by SDS-PAGE and its identification was realized by immunoblotting test.

    RESULTS: The graphs of ion exchange and affinity chromatography showed one peak in all C. albicans isolates obtained from both Malaysian and Iranian samples, infected mice and under high-thermal (42°C) and low-thermal (25°C) shock. In immunoblotting, the location of Hsp90 fragments was obtained around 47, 75 and 82kDa. The least average concentration ratios of Hsp90 were 0.350 and 0.240mg/g for Malaysian and Iranian isolates at 25°C, respectively, while the highest average concentration ratios of Hsp90 were 3.05 and 2.600mg/g for Malaysian and Iranian isolates at 42°C, respectively. There were differences in the ratio amount of Hsp90 between Malaysian isolates (1.01±0.07mg/g) and mice kidneys (1.23±0.28mg/g) as well as between Iranian isolates (0.70±0.19mg/g) and mice kidneys (1.00±0.28mg/g) (P<0.05).

    CONCLUSION: The results showed differences in all situations tested including Iranian and Malaysian isolates, samples treated with temperatures (25°C or 42°C) and before and after infecting the mice (37°C), indicating higher virulent nature of this yeast species in high temperature in human and animal models.

    Matched MeSH terms: Candidiasis/microbiology*
  12. Prevalence of albicans and non-albicans candiduria in a Malaysian medical centre
    Ding CH, Wahab AA, Muttaqillah NA, Tzar MN
    J Pak Med Assoc, 2014 Dec;64(12):1375-9.
    PMID: 25842581
    To determine the proportion of albicans and non-albicans candiduria in a hospital setting and to ascertain if fluconazole is still suitable as empirical antifungal therapy based on antifungal susceptibility patterns of Candida species.
    Matched MeSH terms: Candidiasis/microbiology*
  13. 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: Candidiasis/microbiology*
  14. Isolates of the emerging pathogen Candida auris present in the UK have several geographic origins
    Borman AM, Szekely A, Johnson EM
    Med Mycol, 2017 Jul 01;55(5):563-567.
    PMID: 28204557 DOI: 10.1093/mmy/myw147
    Candida auris has recently emerged as a serious nosocomial health risk, with widespread outbreaks in numerous hospitals worldwide and the existence of geographic region-specific discrete clonal lineages. Here we have compared the rDNA sequences of 24 isolates of Candida auris from 14 different hospital centers in the United Kingdom with those of strains from different international origins present in the public sequence databases. Here we show that UK isolates of C. auris fall into three well-supported clades corresponding to lineages that have previously been reported from India, Malaysia and Kuwait, Japan and Korea, and South Africa, respectively.
    Matched MeSH terms: Candidiasis/microbiology*
  15. The assimilation of different carbon sources in Candida albicans: Fitness and pathogenicity
    Lok B, Adam MAA, Kamal LZM, Chukwudi NA, Sandai R, Sandai D
    Med Mycol, 2021 Feb 04;59(2):115-125.
    PMID: 32944760 DOI: 10.1093/mmy/myaa080
    Candida albicans is a commensal yeast commonly found on the skin and in the body. However, in immunocompromised individuals, the fungi could cause local and systemic infections. The carbon source available plays an important role in the establishment of C. albicans infections. The fungi's ability to assimilate a variety of carbon sources plays a vital role in its colonization, and by extension, its fitness and pathogenicity, as it often inhabits niches that are glucose-limited but rich in alternative carbon sources. A difference in carbon sources affect the growth and mating of C. albicans, which contributes to its pathogenicity as proliferation helps the fungi colonize its environment. The carbon source also affects its metabolism and signaling pathways, which are integral parts of the fungi's fitness and pathogenicity. As a big percentage of the carbon assimilated by C. albicans goes to cell wall biogenesis, the availability of different carbon sources will result in cell walls with variations in rigidity, adhesion, and surface hydrophobicity. In addition to the biofilm formation of the fungi, the carbon source also influences whether the fungi grow in yeast- or mycelial-form. Both forms play different roles in C. albicans's infection process. A better understanding of the role of the carbon sources in C. albicans's pathogenicity would contribute to more effective treatment solutions for fungal infections.
    Matched MeSH terms: Candidiasis/microbiology
  16. 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: Candidiasis/microbiology*
  17. Fulltext Efficacy and safety of posaconazole for the prevention of invasive fungal infections in immunocompromised patients: a systematic review with meta-analysis and trial sequential analysis
    Wong TY, Loo YS, Veettil SK, Wong PS, Divya G, Ching SM, et al.
    Sci Rep, 2020 09 03;10(1):14575.
    PMID: 32884060 DOI: 10.1038/s41598-020-71571-0
    Invasive fungal infections are a potentially life-threatening complication in immunocompromised patients. The aim of this study was to assess the efficacy and safety of posaconazole as compared with other antifungal agents for preventing invasive fungal infections in immunocompromised patients. Embase, CENTRAL, and MEDLINE were searched for randomized conweekmonthtrolled trials (RCTs) up to June 2020. A systematic review with meta-analysis of RCTs was performed using random-effects model. Trial sequential analysis (TSA) was conducted for the primary outcome to assess random errors. A total of five RCTs with 1,617 participants were included. Posaconazole prophylaxis was associated with a significantly lower risk of IFIs (RR, 0.43 [95% CI 0.28 to 0.66, p = 0.0001]) as compared to other antifungal agents. No heterogeneity was identified between studies (I2 = 0%). No significant associations were observed for the secondary outcomes measured, including risk reduction of invasive aspergillosis and candidiasis, clinical failure, all-cause mortality, and treatment-related adverse events, except for infection-related mortality (RR, 0.31 [95% CI 0.15 to 0.64, p = 0.0001]). Subgroup analysis favoured posaconazole over fluconazole for the prevention of IFIs (RR, 0.44 [95% CI 0.28 to 0.70, p = 0.0004]). TSA confirmed the prophylactic benefit of posaconazole against IFIs. Posaconazole is effective in preventing IFIs among immunocompromised patients, particularly those with hematologic malignancies and recipients of allogenic hematopoietic stem cell transplantation.
    Matched MeSH terms: Candidiasis/microbiology
  18. Comparative Study of the Effects of Fluconazole and Voriconazole on Candida glabrata, Candida parapsilosis and Candida rugosa Biofilms
    Madhavan P, Jamal F, Pei CP, Othman F, Karunanidhi A, Ng KP
    Mycopathologia, 2018 Jun;183(3):499-511.
    PMID: 29380188 DOI: 10.1007/s11046-018-0243-z
    Infections by non-albicans Candida species are a life-threatening condition, and formation of biofilms can lead to treatment failure in a clinical setting. This study was aimed to demonstrate the in vitro antibiofilm activity of fluconazole (FLU) and voriconazole (VOR) against C. glabrata, C. parapsilosis and C. rugosa with diverse antifungal susceptibilities to FLU and VOR. The antibiofilm activities of FLU and VOR in the form of suspension as well as pre-coatings were assessed by XTT [2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction assay. Morphological and intracellular changes exerted by the antifungal drugs on Candida cells were examined by scanning electron microscope (SEM) and transmission electron microscope (TEM). The results of the antibiofilm activities showed that FLU drug suspension was capable of killing C. parapsilosis and C. rugosa at minimum inhibitory concentrations (MICs) of 4× MIC FLU and 256× MIC FLU, respectively. While VOR MICs ranging from 2× to 32× were capable of killing the biofilms of all Candida spp tested. The antibiofilm activities of pre-coated FLU were able to kill the biofilms at ¼× MIC FLU and ½× MIC FLU for C. parapsilosis and C. rugosa strains, respectively. While pre-coated VOR was able to kill the biofilms, all three Candida sp at ½× MIC VOR. SEM and TEM examinations showed that FLU and VOR treatments exerted significant impact on Candida cell with various degrees of morphological changes. In conclusion, a fourfold reduction in MIC50 of FLU and VOR towards ATCC strains of C. glabrata, C. rugosa and C. rugosa clinical strain was observed in this study.
    Matched MeSH terms: Candidiasis/microbiology
  19. The inhibitory effects of aureobasidin A on Candida planktonic and biofilm cells
    Tan HW, Tay ST
    Mycoses, 2013 Mar;56(2):150-6.
    PMID: 22882276 DOI: 10.1111/j.1439-0507.2012.02225.x
    Aureobasidin A (AbA) is a cyclic depsipeptide antifungal compound that inhibits a wide range of pathogenic fungi. In this study, the in vitro susceptibility of 92 clinical isolates of various Candida species against AbA was assessed by determining the planktonic and biofilm MICs of the isolates. The MIC(50) and MIC(90) of the planktonic Candida yeast were 1 and 1 μg ml(-1), respectively, whereas the biofilm MIC(50) and MIC(90) of the isolates were 8 and ≥64 μg ml(-1) respectively. This study demonstrates AbA inhibition on filamentation and biofilm development of C. albicans. The production of short hyphae and a lack of filamentation might have impaired biofilm development of AbA-treated cells. The AbA resistance of mature Candidia biofilms (24 h adherent population) was demonstrated in this study.
    Matched MeSH terms: Candidiasis/microbiology*
  20. Fulltext Glyoxylate cycle gene ICL1 is essential for the metabolic flexibility and virulence of Candida glabrata
    Chew SY, Ho KL, Cheah YK, Ng TS, Sandai D, Brown AJP, et al.
    Sci Rep, 2019 02 26;9(1):2843.
    PMID: 30808979 DOI: 10.1038/s41598-019-39117-1
    The human fungal pathogen Candida glabrata appears to utilise unique stealth, evasion and persistence strategies in subverting the onslaught of host immune response during systemic infection. However, macrophages actively deprive the intracellular fungal pathogen of glucose, and therefore alternative carbon sources probably support the growth and survival of engulfed C. glabrata. The present study aimed to investigate the role of the glyoxylate cycle gene ICL1 in alternative carbon utilisation and its importance for the virulence of C. glabrata. The data showed that disruption of ICL1 rendered C. glabrata unable to utilise acetate, ethanol or oleic acid. In addition, C. glabrata icl1∆ cells displayed significantly reduced biofilm growth in the presence of several alternative carbon sources. It was also found that ICL1 is crucial for the survival of C. glabrata in response to macrophage engulfment. Disruption of ICL1 also conferred a severe attenuation in the virulence of C. glabrata in the mouse model of invasive candidiasis. In conclusion, a functional glyoxylate cycle is essential for C. glabrata to utilise certain alternative carbon sources in vitro and to display full virulence in vivo. This reinforces the view that antifungal drugs that target fungal Icl1 have potential for future therapeutic intervention.
    Matched MeSH terms: Candidiasis/microbiology*
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links