Biological, biochemical, and molecular characterization of a new clinical Trichophyton rubrum isolate resistant to terbinafine.
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ABSTRACT:
SUBMITTER: Osborne CS
PROVIDER: S-EPMC1479141 | biostudies-literature | 2006 Jun
REPOSITORIES: biostudies-literature
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Biological, biochemical, and molecular characterization of a new clinical Trichophyton rubrum isolate resistant to terbinafine.
Osborne Colin S CS Leitner Ingrid I Hofbauer Bettina B Fielding Ceri A CA Favre Bertrand B Ryder Neil S NS
Antimicrobial agents and chemotherapy 20060601 6
We have characterized a new clinical strain of Trichophyton rubrum highly resistant to terbinafine but exhibiting normal susceptibility to drugs with other mechanisms of action. Resistance to terbinafine in this strain is caused by a missense mutation in the squalene epoxidase gene leading to the amino acid substitution F397L. ...[more]
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Project description:The multi-antifungal drug-resistant strain (NUBS21012) of Trichophyton rubrum was isolated from a patient with recurrent tinea corporis. The resistant strain encoded Phe at codon 393 instead of Leu (L393F) in the squalene epoxidase (SQLE) gene. The expression of genes encoding ATP-binding cassette transporter proteins increased in the strain compared to that of other strains. This result provides evidence that ATP-binding cassette transporter proteins are closely associated with azole resistance.
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Project description:The diseases caused by dermatophytes are common among several other infections which cause serious threat to human health. It is evident that enzyme squalene epoxidase is responsible for prolonged dermatophyte infection and it is appealing to note that this enzyme is also responsible for fatty acid synthesis in these groups of fungi. In the present study, terbinafine drug which targets enzyme squalene epoxidase has been explored to design its various novel analogues. The present study suggests that many more prominent drug analogues could be constituted which may be crucial towards designing new drug candidates. In the present study, we have designed a series of such analogues viz. [(2E)-6,6-dimethylhept-2-en-4-yn-1-yl](methyl)(naphthalen-1-ylmethyl)amine, N-[8-({[(2E)-6,6-dimethylhept-2-en-4-yn-1-yl](methyl)amino}methyl)naphthalen-1-yl]-2-(sulfoamino) acetamide, {[4-(dihydroxyamino)-8-({[(2E)-6,6-dimethylhept-2-en-4-yn-1-yl](methyl)amino}methyl)naphthalen-1-yl]sulfanyl}methanol and (R)-{[4-({[(2E,6R)-6,7-dimethyloct-2-en-4-yn-1-yl](methyl)amino}methyl)-5-[(hydroxysulfamoyl)amino]naphthalen-1-yl]amino}sulfinic acid. Moreover, further by molecular docking approach the binding between enzyme and designed analogues was further analysed. The present preliminary report suggested a considerably good docking interaction score of -338.75 kcal/mol between terbinafine and squalene epoxidase from Trichophyton rubrum. This preliminary study implies that few designed candidate ligands can be effectual towards the activity of this enzyme and can play crucial role in pathogenesis control of T. rubrum.
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Project description:Two isolates of Candida glabrata, one susceptible and one resistant to azole antifungals, were previously shown to differ in quantity and activity of the cytochrome P-450 14alpha-lanosterol demethylase which is the target for azole antifungals. The resistant isolate also had a lower intracellular level of fluconazole, but not of ketoconazole or itraconazole, than the susceptible isolate. In the present study a 3.7-fold increase in the copy number of the CYP51 gene, encoding the 14alpha-lanosterol demethylase, was found. The amount of CYP51 mRNA transcript in the resistant isolate was eight times greater than it was in the susceptible isolate. Hybridization experiments on chromosomal blots indicated that this increase in copy number was due to duplication of the entire chromosome containing the CYP51 gene. The phenotypic instability of the resistant isolate was demonstrated genotypically: a gradual loss of the duplicated chromosome was seen in successive subcultures of the isolate in fluconazole-free medium and correlated with reversion to susceptibility. The greater abundance of the amplified chromosome induced pronounced differences in the protein patterns of the susceptible and revertant isolates versus that of the resistant isolate, as demonstrated by two-dimensional gel electrophoresis (2D-GE). Densitometry of the 2D-GE product indicated upregulation of at least 25 proteins and downregulation of at least 76 proteins in the resistant isolate.
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Project description:The validity of taxa around Trichophyton rubrum was evaluated by a combination of phenetic and molecular methods. Morphological and physiological features were compared to results of sequencing of the internal transcribed spacer region of the ribosomal operon, PCR fingerprinting, and amplified fragment length polymorphism analysis. The 15 species and varieties investigated (Trichophyton circonvolutum, Trichophyton fischeri, Trichophyton fluviomuniense, Trichophyton glabrum, Trichophyton gourvilii, Trichophyton kanei, Trichophyton kuryangei, Trichophyton megninii, Trichophyton pedis, Trichophyton raubitschekii, Trichophyton rodhaini, Trichophyton rubrum var. nigricans, Trichophyton soudanense, Trichophyton violaceum var. indicum, and Trichophyton yaoundei) were reclassified or synonymized as T. rubrum or T. violaceum.
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Project description:Purpose: Evaluate the effect of terbinafine in T. rubrum gene expression using a co-culture model in conjunction with RNA-seq Methods: T. rubrum and HaCat cells line were co-cultured in RPMI medium supplemented with 5% of fetal bovine serum and treated with 0.0162 µM of terbinafine.The co-culture was incubated for 24 h at 37ºC in a humidified atmosphere containing 5% CO2 , followed RNA by extraction of both organisms, libraries construction and sequence. Results: Our data demonstrated the modulation of several T. rubrum genes involved in the biosynthesis of ergosterol in addition to the target gene of terbinafine that is already known, genes encoding MFS- and ABC-type membrane transporters that are associated with the phenomenon of multidrug resistance, genes that have been discussed in the literature as possible novel targets for antifungal compounds and genes which do not have a known function in T. rubrum yet, but have been modulated in response to the drug. Conclusions: RNA-seq sequencing of the T. rubrum co-culture in the presence of terbinafine showed that several genes of the ergosterol biosynthesis cascade were repressed. We highlight the induction of transmembrane transporters, which may be associated with the efflux of this allylamine. In addition, other genes that could be involved in the pathogenicity of T. rubrum were also modulated in the presence of the drug. In addition, we observed the modulation of hypothetical genes with still unknown functions in T. rubrum but that possess orthologs in other dermatophytes.
2019-11-28 | GSE135095 | GEO
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