Displaying publications 1 - 20 of 24 in total

  1. Qin J, Yang ZL
    Mycologia, 2016 Jan-Feb;108(1):215-26.
    PMID: 26553778 DOI: 10.3852/15-166
    Three new and one previously described species of Physalacria (Physalacriaceae, Agaricales) are reported from China. Specimens of two additional species described from Malaysia and North America were studied for comparison. Placements of these species were corroborated based on morphological observations and molecular evidence from partial sequences of the nuc rDNA internal transcribed spacer regions (ITS) and the 28S D1-D3 region, and genes for translation elongation factor 1-α (tef1α) and the second largest subunit of RNA polymerase II (rpb2). These new species of Physalacria distributed in subtropical China were found on rotten wood of broadleaf trees or bamboo and possess stipitate-capitate basidiomata with four-spored basidia, clamp connections and smooth, inamyloid basidiospores. To facilitate studies of the genus in Asia, a key is provided for all Physalacria species reported from this region.
    Matched MeSH terms: DNA, Fungal/chemistry
  2. Chutrakul C, Peberdy JF
    FEMS Microbiol. Lett., 2005 Nov 15;252(2):257-65.
    PMID: 16214297
    Many species of Trichoderma have attracted interest as agents for the biological control of soil borne fungal pathogens of a range of crop plants. Research on the biochemical mechanisms associated with this application has focused on the ability of these fungi to produce enzymes which lyse fungal cell walls, and antifungal antibiotics. An important group of the latter are the non-ribosomal peptides called peptaibols. In this study Trichoderma asperellum, a strain used in biological control in Malaysia, was found to produce the peptaibol, trichotoxin. This type of peptide molecule is synthesised by a peptide synthetase (PES) enzyme template encoded by a peptide synthetase (pes) gene. Using nucleotide sequences amplified from adenylation (A-) domains as probes, to hybridise against a lambda FIXII genomic library from T. asperellum, 25 clones were recovered. These were subsequently identified as representative of four groups based on their encoding properties for specific amino acid incorporation modules in a PES. This was based on analysis of their amino acid sequences which showed up to 86% identity to other PESs including TEX 1.
    Matched MeSH terms: DNA, Fungal/chemistry
  3. Chew AL, Tan YS, Desjardin DE, Musa MY, Sabaratnam V
    Mycologia, 2014 Sep-Oct;106(5):976-88.
    PMID: 24891424 DOI: 10.3852/13-274
    Three new species and one new variety of bioluminescent Mycena collected from Peninsular Malaysia are described herein. All new species belong to Mycena sect. Calodontes in what is known as the Mycena pura complex. Comprehensive descriptions, photographs, illustrations and comparisons with phenetically similar species are provided. Molecular sequences data from the nuclear internal transcribed spacers (ITS-1 and ITS-2, including the 5.8S rRNA) were used to infer relationships within sect. Calodontes. Axenic cultures were obtained to provide data on culture morphology. This is the first published photographic documentation of bioluminescent basidiomes of members of Mycena sect. Calodontes. Also, this addition brings the total known bioluminescent fungi to 77 species.
    Matched MeSH terms: DNA, Fungal/chemistry
  4. Déon M, Fumanal B, Gimenez S, Bieysse D, Oliveira RR, Shuib SS, et al.
    Fungal Biol, 2014 Jan;118(1):32-47.
    PMID: 24433675 DOI: 10.1016/j.funbio.2013.10.011
    Corynespora cassiicola is an important plant pathogenic Ascomycete causing the damaging Corynespora Leaf Fall (CLF) disease in rubber tree (Hevea brasiliensis). A small secreted glycoprotein named cassiicolin was previously described as an important effector of C. cassiicola. In this study, the diversity of the cassiicolin-encoding gene was analysed in C. cassiicola isolates sampled from various hosts and geographical origins. A cassiicolin gene was detected in 47 % of the isolates, encoding up to six distinct protein isoforms. In three isolates, two gene variants encoding cassiicolin isoforms Cas2 and Cas6 were found in the same isolate. A phylogenetic tree based on four combined loci and elucidating the diversity of the whole collection was strongly structured by the toxin class, as defined by the cassiicolin isoform. The isolates carrying the Cas1 gene (toxin class Cas1), all grouped in the same highly supported clade, were found the most aggressive on two rubber tree cultivars. Some isolates in which no Cas gene was detected could nevertheless generate moderate symptoms, suggesting the existence of other yet uncharacterized effectors. This study provides a useful base for future studies of C. cassiicola population biology and epidemiological surveys in various host plants.
    Matched MeSH terms: DNA, Fungal/chemistry
  5. López-Quintero CA, Atanasova L, Franco-Molano AE, Gams W, Komon-Zelazowska M, Theelen B, et al.
    Antonie Van Leeuwenhoek, 2013 Nov;104(5):657-74.
    PMID: 23884864 DOI: 10.1007/s10482-013-9975-4
    The diversity of Trichoderma (Hypocreales, Ascomycota) colonizing leaf litter as well as the rhizosphere of Garcinia macrophylla (Clusiaceae) was investigated in primary and secondary rain forests in Colombian Amazonia. DNA barcoding of 107 strains based on the internal transcribed spacers 1 and 2 (ITS1 and 2) of the ribosomal RNA gene cluster and the partial sequence of the translation elongation factor 1 alpha (tef1) gene revealed that the diversity of Trichoderma was dominated (71 %) by three common cosmopolitan species, namely Trichoderma harzianum sensu lato (41 %), Trichoderma spirale (17 %) and Trichoderma koningiopsis (13 %). Four ITS 1 and 2 phylotypes (13 strains) could not be identified with certainty. Multigene phylogenetic analysis and phenotype profiling of four strains with an ITS1 and 2 phylotype similar to Trichoderma strigosum revealed a new sister species of the latter that is described here as Trichoderma strigosellum sp. nov. Sequence similarity searches revealed that this species also occurs in soils of Malaysia and Cameroon, suggesting a pantropical distribution.
    Matched MeSH terms: DNA, Fungal/chemistry
  6. Chew AL, Tan YS, Desjardin DE, Musa MY, Sabaratnam V
    Mycologia, 2013 Sep-Oct;105(5):1325-35.
    PMID: 23709573 DOI: 10.3852/13-009
    Mycena illuminans Henn. is described and re-evaluated based on recently collected material from peninsular Malaysia, providing comprehensive descriptions, illustrations and photographs. In addition to morphological data, axenic monokaryon and dikaryon cultures were established to provide data on culture morphology and the mating system of the species. Molecular sequences data from the nuclear large subunit (LSU) gene also are presented, confirming that M. illuminans is not a synonym of Mycena chlorophos.
    Matched MeSH terms: DNA, Fungal/chemistry
  7. Naumov GI, Lee CF, Naumova ES
    Antonie Van Leeuwenhoek, 2013 Jan;103(1):217-28.
    PMID: 22941248 DOI: 10.1007/s10482-012-9803-2
    Genetic hybridization, sequence and karyotypic analyses of natural Saccharomyces yeasts isolated in different regions of Taiwan revealed three biological species: Saccharomyces arboricola, Saccharomyces cerevisiae and Saccharomyces kudriavzevii. Intraspecies variability of the D1/D2 and ITS1 rDNA sequences was detected among S. cerevisiae and S. kudriavzevii isolates. According to molecular and genetic analyses, the cosmopolitan species S. cerevisiae and S. kudriavzevii contain local divergent populations in Taiwan, Malaysia and Japan. Six of the seven known Saccharomyces species are documented in East Asia: S. arboricola, S. bayanus, S. cerevisiae, S. kudriavzevii, S. mikatae, and S. paradoxus.
    Matched MeSH terms: DNA, Fungal/chemistry
  8. Freeman MA, Sommerville C
    Parasit Vectors, 2011;4:231.
    PMID: 22166354 DOI: 10.1186/1756-3305-4-231
    A microsporidian hyperparasite, Desmozoon lepeophtherii, of the parasitic copepod Lepeophtheirus salmonis (salmon louse), infecting farmed Atlantic salmon (Salmo salar), was first discovered in the west of Scotland in 2000. Heavily infected salmon lice are easily recognised as they have large opaque inclusions distributed throughout the body. The prevalence of salmon lice with visible signs of microsporidiosis can be up to 10% of the population from certain farm sites. The microsporidian was also isolated from the host Atlantic salmon suggesting it may have a two host life cycle. The authors believe that the infection in immunocompetent salmon may be latent, becoming acute during periods of infection with another pathogen or during sexual maturation. Since its first discovery in Scotland, Desmozoon lepeophtherii has been subsequently reported from Norway, and more recently from the Pacific coast of North America.
    Matched MeSH terms: DNA, Fungal/chemistry
  9. Lim SL, Tay ST
    Trop Biomed, 2011 Aug;28(2):438-43.
    PMID: 22041766
    The biodiversity and the killer activity of yeasts isolated from various types of fermented food in Malaysia were investigated in this study. Of 252 yeasts isolated from 48 fermented food samples in this study, 19 yeast species were identified based on sequence analysis of the ITS1-5.8S-ITS2 partial fragments of the yeasts. A total of 29 (11.5%) of the yeast isolates demonstrated killer activity to at least one Candida species tested in this study; including 22 isolates of Trichosporon asahii, 4 isolates of Pichia anomala, and one isolate each of Pichia norvegensis, Pichia fermentans and Issatchenkia orientalis, respectively. The presence of killer yeasts reflects antagonism that occurs during microbial interaction in the fermented food, whereby certain yeasts produce killer toxins and possibly other toxic substances in competition for limited nutrients and space. The anti-Candida activity demonstrated by killer yeasts in this study should be further explored for development of alternative therapy against candidiasis.
    Matched MeSH terms: DNA, Fungal/chemistry
  10. Tan HW, Tay ST
    Trop Biomed, 2011 Apr;28(1):175-80.
    PMID: 21602784
    This study describes the killer phenotypes of tropical environmental yeasts and the inhibition effects of the culture filtrates on the biofilm of Candida albicans. A total of 26 (10.5%) of 258 yeast isolates obtained from an environmental sampling study demonstrated killer activity to Candida species. The killer yeasts were identified as species belonging to the genus Aureobasidium, Pseudozyma, Ustilago and Candida based on sequence analysis of the ITS1-5.8S-ITS2 region of the yeasts. Pseudozyma showed the broadest killing effects against sensitive strains of Candida. New species of Ustilago and Pseudozyma demonstrating killer phenotypes were identified in this study. Interestingly, more than 50% reduction in the metabolic activity of Candida albicans biofilm was noted after exposure to the culture filtrates of the nine killer yeasts. Purification and characterization of toxin and metabolites are essential for understanding the yeast killing effects.
    Matched MeSH terms: DNA, Fungal/chemistry
  11. Sim JH, Khoo CH, Lee LH, Cheah YK
    J. Microbiol. Biotechnol., 2010 Apr;20(4):651-8.
    PMID: 20467234
    Garcinia is commonly found in Malaysia, but limited information is available regarding endophytic fungi associated with this plant. In this study, 24 endophytic fungi were successfully recovered from different parts of two Garcinia species. Characterization of endophytic fungi was performed based on the conserved internal transcribed spacer (ITS) region sequence analysis and the antimicrobial properties. Results revealed that fruits of the plant appeared to be the highest inhabitation site (38 %) as compared with others. Glomerella sp., Guignardia sp., and Phomopsis sp. appeared to be the predominant endophytic fungi group in Garcinia mangostana and Garcinia parvifolia. Phylogenetic relationships of the isolated endophytic fungi were estimated from the sequences of the ITS region. On the other hand, antibacterial screening showed 11 of the isolates possessed positive response towards pathogenic and nonpathogenic bacteria. However, there was no direct association between certain antibacterial properties with the specific genus observed.
    Matched MeSH terms: DNA, Fungal/chemistry
  12. Siddiquee S, Yusof NA, Salleh AB, Abu Bakar F, Heng LY
    Bioelectrochemistry, 2010 Aug;79(1):31-6.
    PMID: 19945357 DOI: 10.1016/j.bioelechem.2009.10.004
    A new electrochemical biosensor is described for voltammetric detection of gene sequence related to Trichoderma harzianum. The sensor involves immobilization of a 20 base single-stranded probe (ssDNA), which is complementary to a specific gene sequence related to T. harzianum on a gold electrode through specific adsorption. The DNA probe was used to determine the amount of target gene in solution using methylene blue (MB) as the electrochemical indicator. The covalently immobilized probe could selectively hybridize with the target DNA to form a hybrid on the surface despite the bases being attached to the electrode. The changes in the peak currents of methylene blue (MB), an electroactive label, were observed upon hybridization of probe with the target. Peak currents were found to increase in the following order: hybrid-modified AuE and the probe-modified AuE which localized to the affinity of MB. Control experiments with the non-complementary oligonucleotides were performed to assess whether the DNA biosensor responds selectively, via hybridization, to the target. DNA biosensor also able to detect microorganism at the species levels without nucleic acid amplification. The redox current was linearly related to the concentration of target oligonucleotide DNA, ranged from 1-20 ppm. Numerous factors, affecting the probe immobilization, target hybridization and indicator binding reactions are optimized to maximize the sensitivity and reduce the assay time.
    Matched MeSH terms: DNA, Fungal/chemistry
  13. Ng KP, Soo-Hoo TS, Na SL, Tay ST, Hamimah H, Lim PC, et al.
    Mycopathologia, 2005 Jun;159(4):495-500.
    PMID: 15983734
    Hortaea werneckii is an environmental dematiaceous fungus found in the halophilic environment. It causes tinea nigra. We report the isolation of H. werneckii from blood and splenic abscess of two patients with acute myelomonocytic leukaemia. H. werneckii grew at room temperature but not at 37 degrees C, it was identified by biochemical tests, growth characteristics and the presence of conspicuous collarette intercalary on dividing yeast cells. The use of specific oligonucleotide primer Hor-F (5'-TGGACACCTTCA TAACTCTTG-3') and Hor-R (5'-TCACAACGCTTAGAGACGG-3') confirmed the two isolates were H. werneckii. The sequence for 281 nucleotide of HW299 and HW403 were 99% identical but differed only in one nucleotide. In vitro anti-fungal susceptibility testing showed that the isolates were resistant to amphotericin B and flucytosine.
    Matched MeSH terms: DNA, Fungal/chemistry
  14. Mohd Tap R, Sabaratnam P, Ahmad NA, Abd Razak MF, Hashim R, Ahmad N
    Mycopathologia, 2015 Aug;180(1-2):137-41.
    PMID: 25894509 DOI: 10.1007/s11046-015-9890-5
    An 11-year-old girl presented with multiple blisters on her the right foot complicated with cellulitis. The conventional and molecular identification were performed on the culture. The internal transcribed spacer (ITS) region in rRNA gene of the isolate was amplified by PCR. The sequence of the amplified ITS region matched 99 % with that of Chaetomium globosum in the GenBank. This is the first report describing C. globosum causing cutaneous infection in Malaysia.
    Matched MeSH terms: DNA, Fungal/chemistry
  15. Yong HY, Bakar FD, Illias RM, Mahadi NM, Murad AM
    Braz J Microbiol, 2013 Dec;44(4):1241-50.
    PMID: 24688518
    The mitogen-activated protein (MAP) kinase pathways has been implicated in the pathogenicity of various pathogenic fungi and plays important roles in regulating pathogenicity-related morphogenesis. This work describes the isolation and characterization of MAP kinase gene, Cgl-SLT2, from Colletotrichum gloeosporioides. A DNA sequence, including 1,633 bp of Cgl-SLT2 open-reading frame and its promoter and terminator regions, was isolated via DNA walking and cloned. To analyze gene function, a gene disruption cassette containing hygromycin-resistant gene was constructed, and Cgl-SLT2 was inactivated via gene deletion. Analysis on Cgl-slt2 mutant revealed a defect in vegetative growth and sporulation as compared to the wild-type strain. When grown under nutrient-limiting conditions, hyperbranched hyphal morphology was observed in the mutant. Conidia induction for germination on rubber wax-coated hard surfaces revealed no differences in the percentage of conidial germination between the wild-type and Cgl-slt2 mutant. However, the percentage of appressorium formation in the mutant was greatly reduced. Bipolar germination in the mutant was higher than in the wild-type at 8-h post-induction. A pathogenicity assay revealed that the mutant was unable to infect either wounded or unwounded mangoes. These results suggest that the Cgl-SLT2 MAP kinase is required for C. gloeosporioides conidiation, polarized growth, appressorium formation and pathogenicity.
    Matched MeSH terms: DNA, Fungal/chemistry
  16. 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: DNA, Fungal/chemistry
  17. Rahim MB, Syed MA, Shukor MY
    J. Basic Microbiol., 2012 Oct;52(5):573-81.
    PMID: 22144174 DOI: 10.1002/jobm.201100116
    As well as for chemical and environmental reasons, acrylamide is widely used in many industrial applications. Due to its carcinogenicity and toxicity, its discharge into the environment causes adverse effects on humans and ecology alike. In this study, a novel acrylamide-degrading yeast has been isolated. The isolate was identified as Rhodotorula sp. strain MBH23 using ITS rRNA analysis. The results showed that the best carbon source for growth was glucose at 1.0% (w/v). The optimum acrylamide concentration, being a nitrogen source for cellular growth, was at 500 mg l(-1). The highest tolerable concentration of acrylamide was 1500 mg l(-1) whereas growth was completely inhibited at 2000 mg l(-1). At 500 mg l(-1), the strain MBH completely degraded acrylamide on day 5. Acrylic acid as a metabolite was detected in the media. Strain MBH23 grew well between pH 6.0 and 8.0 and between 27 and 30 °C. Amides such as 2-chloroacetamide, methacrylamide, nicotinamide, acrylamide, acetamide, and propionamide supported growth. Toxic heavy metals such as mercury, chromium, and cadmium inhibited growth on acrylamide.
    Matched MeSH terms: DNA, Fungal/chemistry
  18. Tay ST, Tan HW, Na SL, Lim SL
    J. Med. Microbiol., 2011 Nov;60(Pt 11):1591-1597.
    PMID: 21700741 DOI: 10.1099/jmm.0.032854-0
    In this study, six clinical isolates (two from blood, two from urine and one each from a bronchoalveolar lavage and a vaginal swab) were identified as Candida rugosa based on carbohydrate assimilation profiles using API 20C AUX and ID32 C kits (bioMérieux). Sequence analysis of the D1/D2 domain of the yeasts differentiated the isolates into two subgroups, A and B (three isolates per subgroup), which were closely related (99.1-99.6 % nucleotide similarity) to C. rugosa strain ATCC 10571. Compared with the C. rugosa type strain, the intergenic transcribed spacer (ITS) nucleotide similarity for subgroup A was only 89.2 % (29 mismatches and one deletion) and for subgroup B was 93.7 % (20 mismatches). All isolates grew green colonies on Oxoid Chromogenic Candida Agar, with darker pigmentation observed for subgroup A. All isolates were able to grow at 25-42 °C but not at 45 °C. The isolates had identical enzymic profiles, as determined by API ZYM (bioMérieux) analysis, and produced proteinase. High amphotericin MICs (≥1 µg ml(-1)) were noted for two isolates from each subgroup. Dose-dependent susceptibility to fluconazole (MIC 32 µg ml(-1)) was noted in a blood isolate. The biofilms of the isolates demonstrated increased resistance to amphotericin and fluconazole. The greater ITS sequence variability of subgroup A isolates is in support of this yeast being recognized as a distinct species; however, further verification using more sophisticated molecular approaches is required. A sequence comparison study suggested the association of subgroup A with environmental sources and subgroup B with clinical sources. Accurate identification and antifungal susceptibility testing of C. rugosa are important in view of its decreased susceptibility to amphotericin and fluconazole. The ITS region has been shown to be a valuable region for differentiation of closely related subgroups of C. rugosa.
    Matched MeSH terms: DNA, Fungal/chemistry
  19. Tap RM, Ramli NY, Sabaratnam P, Hashim R, Bakri AR, Bee LB, et al.
    Mycopathologia, 2016 Aug;181(7-8):531-7.
    PMID: 27010640 DOI: 10.1007/s11046-016-0002-y
    The number of new fungal pathogens is increasing due to growing population of immunocompromised patients and advanced identification techniques. Fereydounia khargensis is a yeast and was first described in 2014 from environmental samples. As far as we know, this is the first report of human infections associated with F. khargensis. The yeasts were isolated from blood of a HIV-positive patient and pleural fluid of chronic renal failure patient. Amplification and sequencing of the internal transcribed spacer and the large subunit regions confirmed the identity of the isolates. Both isolates showed multi-drug resistance to antifungal agents tested.
    Matched MeSH terms: DNA, Fungal/chemistry
  20. Freeman MA, Kasper JM, Kristmundsson Á
    Parasit Vectors, 2013;6:49.
    PMID: 23445616 DOI: 10.1186/1756-3305-6-49
    Commercial fisheries of lumpfish Cyclopterus lumpus have been carried out in Iceland for centuries. Traditionally the most valuable part is the eggs which are harvested for use as a caviar substitute.Previously reported parasitic infections from lumpfish include an undescribed intranuclear microsporidian associated with abnormal kidneys and mortalities in captive lumpfish in Canada. During Icelandic lumpfish fisheries in spring 2011, extensive enlargements to the kidneys were observed in some fish during processing. The aim of this study was to identify the pathogen responsible for these abnormalities.
    Matched MeSH terms: DNA, Fungal/chemistry
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