(.) ITS genotype VIII, also known as , is a new species of the / complex and its first records, albeit under a different species name, are from the Indian subcontinent, Middle Eastern Asia, and West Asia genotype VIII (. ) has spread globally and has now been documented in over 30 countries.
View Article and Find Full Text PDFis an emerging pathogen causing recalcitrant skin infections and exhibiting multiple resistances to azoles and allylamines. Squalene epoxidase mutants often show association with azole resistance. RT-PCR gene expression analysis helps to elucidate the connection between ergosterol biosynthesis regulation and efflux control through the activation of multidrug resistance (MDR) and major facilitator superfamily (MFS1) transporters as well as heat shock proteins (HSP).
View Article and Find Full Text PDFFor more than 30 years, an 82-year-old man has been suffering from tinea corporis generalisata in the sense of Trichophyton rubrum syndrome. The patient received long-term treatment with terbinafine. Fluconazole had no effect.
View Article and Find Full Text PDFDermal fungal infections seem to have increased over recent years. There is further a shift from anthropophilic dermatophytes to a growing prevalence of zoophilic species and the emergence of resistant strains. New antifungals are needed to combat these fungi and their resting spores.
View Article and Find Full Text PDFBackground: The T indotineae population shows a high amount of terbinafine resistant isolates based on different point mutations of squalene epoxidase erg1 (ergosterol) gene. A significant proportion of these isolates also show azole resistance.
Objectives: Elucidation of the molecular mechanism for azole resistance, especially the identification of mutations in the sterol 14-α demethylase Erg11 genes, which encode for enzymes interacting with azoles.
Chronic recalcitrant dermatophytoses, due to (.) Type VIII are on the rise in India and are noteworthy for their predominance. It would not be wrong to assume that travel and migration would be responsible for the spread of .
View Article and Find Full Text PDFBackground: The Indian ITS genotype VIII Trichophyton mentagrophytes population shows a high amount of different erg1 (ergosterol) mutants encoding for squalene epoxidase, which catalyses the first step of ergosterol biosynthesis.
Objectives: Illumination of the implication of point mutations at position Ala448Thr in single and double erg1 T mentagrophytes mutants because mutants of this type were abundantly found within the Indian fungal population.
Methods: Growth in fluconazole or terbinafine containing medium was analysed using a microplate-laser-nephelometry (MLN)-based growth assay.
Background: An alarming increase in recalcitrant dermatophytosis has been witnessed in India over the past decade. Drug resistance may play a major role in this scenario.
Objectives: The aim of the present study was to determine the prevalence of in vitro resistance to terbinafine, itraconazole and voriconazole in dermatophytes, and to identify underlying mutations in the fungal squalene epoxidase (SQLE) gene.
Terbinafine resistant Indian ITS genotype VIII strain was identified by partial sequencing of the squalene epoxidase gene using DNA isolated from infected scales. This method allowed the rapid identification of single point mutations within the squalene epoxidase gene, even before a fungal culture was obtained. Terbinafine resistance was indicated by the amino acid position switch Phe397Leu based on a single point mutation of the codon changing it from TTC to CTC.
View Article and Find Full Text PDFThe disease burden of chronic-relapsing and therapy-refractory superficial dermatophytosis dramatically increased in India within the past 5-6 years. In order to evaluate the prevalence of this trend, 201 skin scrapings were collected from patients from all parts of India and were tested for dermatophytes using both fungal culture and a PCR-ELISA directly performed with native skin scrapings. Fungal culture material was identified by genomic Sanger sequencing of the internal transcribed spacer (ITS) region and the translation elongation factor (TEF)-1α gene.
View Article and Find Full Text PDFAn alarming pan Indian increase in the incidence of superficial dermatophytosis has been noticed over the past 5-6 years. Recent studies have demonstrated emerging predominance of Trichophyton (T.) mentagrophytes as the causative organism in such cases.
View Article and Find Full Text PDFAbsidia glauca and Parasitella parasitica constitute a versatile experimental system for studying horizontal gene transfer between a mucoralean host and its fusion parasite. The A. glauca chondriome has a length of approximately 63 kb and a GC content of 28%.
View Article and Find Full Text PDFSexual communication between complementary mating partners in the fungal group of zygomycetes is mediated by the trisporoid pheromone system. A key enzyme towards biosynthesis of hormonally active trisporoids is 4-dihydromethyltrisporate dehydrogenase (TSP1), an enzyme occurring in all zygomycetous fungi. Trisporic acid and some of its precursor molecules serve as pheromones for recognizing complementary mating partners and for induction of the differentiation program towards sexual spore formation.
View Article and Find Full Text PDFThe mitochondrial DNA (mtDNA) ofAbsidia glaucahas been completely sequenced. It is 63,080 bp long, has a G+C content of 28%, and contains the standard fungal gene set.A.
View Article and Find Full Text PDFRecognition of food and, in consequence, ingestion of digestible particles is a prerequisite for energy metabolism in Tetrahymena pyriformis. Understanding why some particles are ingested and digested, whereas others are not, is important for many fields of research, e.g.
View Article and Find Full Text PDFThe complete mitochondrial DNA sequence of the Mucor-related fungus Parasitella parasitica has been sequenced. It has a G+C content of 30% and a total length of 83,361 bp. All protein-coding genes normally found in fungi are present in the sequence.
View Article and Find Full Text PDFEndosymbiosis in ciliates is a common and highly diverse phenomenon in nature, but its development at the mechanistic level and the origins are not easy to understand, since these associations may have arisen at any time during evolution. Therefore a laboratory model is helpful. It could be provided by the interaction of Tetrahymena pyriformis and Escherichia coli.
View Article and Find Full Text PDFCompared with prokaryotes, where horizontal gene transfer events are frequently found and can be studied in the laboratory at the mechanistic level, few systems are known that allow direct experimental access to parasexual phenomena in eukaryotes. In zygomycetes, a basal lineage of fungi, several mycoparasitic fungi are known that inevitably form a cytoplasmic continuum with their hosts during infection. We provide evidence that, corresponding to the expectation suggested by the morphology of the infection process, gene transfer occurs from the parasite to the host.
View Article and Find Full Text PDFThe putative mating type locus of mucoralean fungi consists of a single high mobility group (HMG)-domain transcription factor gene, sexM or sexP, flanked by genes for an RNA helicase and a triosephosphate transporter. We used degenerate primers derived from the amino acid sequence of the RNA helicase to sequence a fragment of this gene from Mucor mucedo. This fragment was extended by inverse PCR to obtain the complete sequences of the sex loci from both mating types of M.
View Article and Find Full Text PDFTransformation of fungi by complementation of auxotrophs is generally much more reliable than usage of antibiotic resistance markers. In order to establish such a system for the model zygomycete Absidia glauca, a stable methionine auxotrophic mutant was isolated after X-ray mutagenesis of the minus mating type and characterized at the molecular level. The mutant is disrupted in the coding region of the Met2-1 gene, encoding homoserine O-acetyltransferase.
View Article and Find Full Text PDFDermatophytes cause the majority of superficial mycoses in humans and animals. However, little is known about the pathogenicity of this specialized group of filamentous fungi, for which molecular research has been limited thus far. During experimental infection of guinea pigs by the human pathogenic dermatophyte Arthroderma benhamiae, we recently detected the activation of the fungal gene encoding malate synthase AcuE, a key enzyme of the glyoxylate cycle.
View Article and Find Full Text PDFBackground: Millions of humans and animals suffer from superficial infections caused by a group of highly specialized filamentous fungi, the dermatophytes, which exclusively infect keratinized host structures. To provide broad insights into the molecular basis of the pathogenicity-associated traits, we report the first genome sequences of two closely phylogenetically related dermatophytes, Arthroderma benhamiae and Trichophyton verrucosum, both of which induce highly inflammatory infections in humans.
Results: 97% of the 22.
The NADP-dependent 4-dihydrotrisporin-dehydrogenase is a (-) mating-type-specific enzyme in the pathway from beta-carotene to trisporic acid. This substance and its isomers and derivatives represent the general system of sexual communication in zygomycetes. The (-) mating type of Mucor mucedo was stimulated by trisporic acid and the enzyme was purified by ion exchange and affinity chromatography.
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