Biological, biochemical, and molecular characterization of a new clinical Trichophyton rubrum isolate resistant to terbinafine.
Ontology highlight
ABSTRACT:
SUBMITTER: Osborne CS
PROVIDER: S-EPMC1479141 | biostudies-literature | 2006 Jun
REPOSITORIES: biostudies-literature
Publications
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]
Similar Datasets
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.
| S-EPMC4456508 | biostudies-literature
Project description:There has only been one clinically confirmed case of terbinafine resistance in dermatophytes, where six sequential Trichophyton rubrum isolates from the same patient were found to be resistant to terbinafine and cross-resistant to other squalene epoxidase (SE) inhibitors. Microsomal SE activity from these resistant isolates was insensitive to terbinafine, suggesting a target-based mechanism of resistance (B. Favre, M. Ghannoum, and N. S. Ryder, Med. Mycol. 42:525-529, 2004). In this study, we have characterized at the molecular level the cause of the resistant phenotype of these clinical isolates. Cloning and sequencing of the SE gene and cDNA from T. rubrum revealed the presence of an intron in the gene and an open reading frame encoding a protein of 489 residues, with an equivalent similarity (57%) to both yeast and mammalian SEs. The nucleotide sequences of SE from two terbinafine-susceptible strains were identical whereas those of terbinafine-resistant strains, serially isolated from the same patient, each contained the same single missense introducing the amino acid substitution L393F. Introduction of the corresponding substitution in the Candida albicans SE gene (L398F) and expression of this gene in Saccharomyces cerevisiae conferred a resistant phenotype to the transformants when compared to those expressing the wild-type sequence. Terbinafine resistance in these T. rubrum clinical isolates appears to be due to a single amino acid substitution in SE.
| S-EPMC1168638 | biostudies-literature
Project description:The dermatophyte Trichophyton rubrum is the main causative agent of dermatophytoses worldwide. Although a superficial mycosis, its incidence has been increasing especially among diabetic and immunocompromised patients. Terbinafine is commonly used for the treatment of infections caused by dermatophytes. However, cases of resistance of T. rubrum to this allylamine were reported even with the efficacy of this drug. The present study is the first to evaluate the effect of terbinafine using a co-culture model of T. rubrum and human keratinocytes, mimicking a fungus-host interaction, in conjunction with RNA-seq technique. Our data showed the repression of several genes involved in the ergosterol biosynthesis cascade and the induction of genes encoding major facilitator superfamily (MFS)- and ATP-binding cassette superfamily (ABC)-type membrane transporter which may be involved in T. rubrum mechanisms of resistance to this drug. We observed that some genes reported in the scientific literature as candidates of new antifungal targets were also modulated. In addition, we found the modulation of several genes that are hypothetical in T. rubrum but that possess known orthologs in other dermatophytes. Taken together, the results indicate that terbinafine can act on various targets related to the physiology of T. rubrum other than its main target of ergosterol biosynthetic pathway.
| S-EPMC6963840 | biostudies-literature
Project description:Extensive dermatophytosis caused by terbinafine-resistant Trichophyton indotineae harboring Phe397Leu and Leu393Ser substitutions in the squalene epoxidase enzyme was diagnosed in France. Analysis of internal transcribed spacer sequences revealed the wide spread of this species in Asia and Europe. Detection of T. indotineae in animals suggests their possible role as reservoirs.
| S-EPMC8714191 | biostudies-literature
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.
| S-EPMC164098 | biostudies-other
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.
| S-EPMC87382 | biostudies-literature
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
Project description:Several prolonged and significant outbreaks of dermatophytosis caused by Trichophyton indotineae, a new emerging terbinafine-resistant species, have been ongoing in India in recent years, and have since spread to various countries outside Asia. Miltefosine, an alkylphosphocholine, is the most recently approved drug for the treatment of both visceral and cutaneous leishmaniasis. Miltefosine in vitro activity against terbinafine-resistant and susceptible T. mentagrophytes/T. interdigitale species complex, including T. indotineae, is limited. The current study aimed to assess miltefosine's in vitro activity against dermatophyte isolates, which are the most common causes of dermatophytosis. Miltefosine, terbinafine, butenafine, tolnaftate, and itraconazole susceptibility testing was performed using Clinical and Laboratory Standards Institute broth microdilution methods (CLSI M38-A3) against 40 terbinafine-resistant T. indotineae isolates and 40 terbinafine-susceptible T. mentagrophytes/T. interdigitale species complex isolates. Miltefosine had MIC ranges of 0.063-0.5 µg/mL and 0.125-0.25 µg/mL against both terbinafine-resistant and susceptible isolates. In terbinafine-resistant isolates, the MIC50 and MIC90 were 0.125 µg/mL and 0.25 µg/mL, respectively, and 0.25 µg/mL in susceptible isolates. Miltefosine had statistically significant differences in MIC results when compared to other antifungal agents (p-value 0.05) in terbinafine-resistant strains. Accordingly, the findings suggest that miltefosine has a potential activity for treating infections caused by terbinafine-resistant T. indotineae. However, further studies are needed to determine how well this in vitro activity translates into in vivo efficacy.
| S-EPMC10146699 | biostudies-literature
Project description:Dermatophytes are common causes of skin, hair, and nail infections in humans. The most common species causing infections in humans are Trichophyton rubrum, Trichophyton mentagrophytes, and Trichophyton interdigitale. Outbreaks of recalcitrant dermatophytosis have been reported in parts of South Asia, including those caused by a hypervirulent and resistant species, Trichophyton indotineae. We evaluated the antifungal susceptibility profiles of dermatophytes received by our laboratory from institutions across North America between 2021 and 2022 and performed species identification for isolates deemed to demonstrate in vitro resistance. Susceptibility testing was performed by CLSI broth microdilution methods, and species identification was performed by DNA sequence analysis. During this 2-year period, 271 dermatophyte isolates were included, the majority of which demonstrated low MIC values for terbinafine (geometric mean [GM] and modal MIC, 0.031 μg/mL and 0.008 μg/mL, respectively) and the azoles itraconazole, posaconazole, and voriconazole (0.035 to 0.049 μg/mL and ≤0.03 μg/mL). However, 18.6% of the isolates tested were resistant to terbinafine (MIC ≥ 0.5 μg/mL), including 21 T. rubrum and 21 T. indotineae isolates. These isolates were received from several different states in the United States and two provinces in Canada. In contrast, resistance to itraconazole was relatively rare. We also searched our laboratory database for earlier isolates that were resistant to terbinafine and identified 3 additional T. indotineae isolates, the earliest of which was from 2017. These results demonstrate that terbinafine resistance in dermatophytes was relatively common over this 2-year period and that T. indotineae is present in multiple areas in North America. Continued surveillance is warranted.
| S-EPMC10446870 | biostudies-literature
Project description:A 26-year-old male patient referred to our center with a history of extremely itchy crusted skin lesions in his groins for one year. Moreover, his friend, a 25-year-old male, also developed similar lesions in the groin after using the shared pool, whose condition also did not improve with similar treatment. A regular mycology test (direct and culture test) was performed, as well as molecular examination. The antifungal susceptibility assay to terbinafine, itraconazole, posaconazole, fluconazole, and voriconazole was conducted according to the Clinical and Laboratory Standards Institute M38 third ed. The sequencing study identified T. tonsurans as the causative organism in both patients. The abovementioned organism isolated from both patients displayed resistance against terbinafine and fluconazole (MIC ≥ 4 µg/ml and MIC ≥ 8 µg/ml, respectively). Moreover, the susceptibility of both subjects to posaconazole (0.313 µg/ml), voriconazole (0.25-0.0625 µg/ml), and (1 µg/ml) itraconazole increased. The present report aimed to emphasize the increase in antifungal resistance and a demand for antifungal stewardship, to control this public health threat.
| S-EPMC8677411 | biostudies-literature