Growth inhibitory response and ultrastructural modification of oral-associated candidal reference strains (ATCC) by Piper betle L. extract

Candida species have been associated with the emergence of strains resistant to selected antifungal agents. Plant products have been used traditionally as alternative medicine to ease mucosal fungal infections. This study aimed to investigate the effects of Piper betle extract on the growth profile and the ultrastructure of commonly isolated oral candidal cells. The major component of Po betle was identified using liquid chromatography-mass spectrophotometry （LC-MS/MS）. Seven ATCC control strains of Candida species were cultured in yeast peptone dextrose broth under four different growth environments： （i） in the absence of P. betle extract; and in the presence of P. beUeextract at respective concentrations of （ii） 1 mg.mL-1; （iii） 3 mg.mL-1; and （iv） 6 mg.mL- 1 The growth inhibitory responses of the candidal cells were determined based on changes in the specific growth rates （μ）. Scanning electron microscopy （SEM） was used to observe any ultrastructural alterations in the candida colonies. LC-MS/MS was performed to validate the presence of bioactive compounds in the extract. Following treatment, it was observed that the p-values of the treated cells were significantly different than those of the untreated cells （P〈0.05）, indicating the fungistatic properties of the P. beUe extract. The candidal population was also reduced from an average of 13.44× 10^6 to 1.78×10^6 viable cell counts （CFU）.mL-1, SEM examination exhibited physical damage and considerable morphological alterations of the treated cells. The compound profile from LC-MS/MS indicated the presence of hydroxybenzoic acid, chavibetol and hydroxychavicol in P. betle extract. The effects of P. betle on candida cells could potentiate its antifungal activity.

Bioluminescent fungi from Peninsular Malaysia-a taxonomic and phylogenetic overview

Fifteen bioluminescent fungi recently collected from Peninsular Malaysia are analysed herein.The phylogeny of the Malaysian bioluminescent fungi and closely related taxa were evaluated with molecular data from the nuclear ribosomal large subunit(LSU),RNA polymerase 2 second largest subunit(RPB2)and internal transcribed spacers(ITS)gene regions.DNA sequences data support the circumscription of species based on the morphological species concept,but was unable to fully support the current sectional delimitation of genus Mycena.Of the 15 taxa analysed here,four are novel species described herein,viz.Mycena gombakensis,M.nocticaelum,M.coralliformis and Panellus luxfilamentus;while four taxa of Mycena sect.Calodontes were recently described as new.One species(M.noctilucens)represents a new distribution record to Peninsular Malaysia,and six species(Neonothopanus nambi,Filoboletus manipularis,P.luminescens,Roridomyces pruinosoviscidus,M.chlorophos and M.illuminans)have been previously reported.Roridomyces pruinosoviscidus is accepted as a new combination based on morphological and phylogenetic data.Culture morphology data indicate its potential for taxon delimitation as axenic cultures of each species produced unique and distinguishable characteristics.Comprehensive descriptions,illustrations and photographs are provided on basidiome and culture morphology.A key to aid in species identification,comparisons with allied species and data on basidiome and mycelium luminescence are also provided.This study gives the first report on mycelial luminescence for M.noctilucens,P.luminescens,R.pruinosoviscidus as well as all new species described herein.The reports in this study bring the total known luminescent fungi worldwide to 81 species.