Detection of terbinafine-resistant Trichophyton indotineae isolates within the Trichophyton mentagrophytes species complex isolated from patients in Hue City, Vietnam: A comprehensive analysis.

The Trichophyton mentagrophytes complex comprises a group of dermatophyte fungi responsible for various dermatological infections. The increasing drug resistance of this species complex, especially terbinafine resistance of Trichophyton indotineae, is a major concern in dermatologist practice. This study provides a comprehensive analysis of T. mentagrophytes complex strains isolated from patients in Hue City, Vietnam, focusing on their phenotypic and genetic characteristics, antifungal susceptibility profiles, and molecular epidemiology. Keratinophilic fungi from dermatophytosis culture samples were identified morphologically and phenotypically, with species and genotypes confirmed by internal transcribed spacer sequencing and phylogenetic analysis. Antifungal susceptibility testing was carried out to evaluate their susceptibility to itraconazole, voriconazole, and terbinafine. The 24% (n = 27/114) of superficial mycoses were phenotypically attributed to T. mentagrophytes complex isolates. Trichophyton interdigitale, mainly genotype II*, was predominant (44.4%), followed by T. mentagrophytes genotype III* (22.2%), T. indotineae (14.8%), T. tonsurans (11.2%), and T. mentagrophytes (7.4%). While all isolates were susceptible to itraconazole and voriconazole, half of T. indotineae isolates exhibited resistance to terbinafine, linked to the Phe397Leu mutation in the SQLE protein. This study highlighted the presence of terbinafine-resistant T. indotineae isolates in Vietnam, emphasizing the need to investigate dermatophyte drug resistance and implement effective measures in clinical practice.

Species diversity within the Trichophyton mentagrophytes complex isolated from dermatophytosis in Hue City, Vietnam, was observed. Terbinafine-resistant T. indotineae isolates were detected for the first time in Vietnam, emphasizing the importance of implementing antifungal susceptibility testing to effectively manage and prevent the spread of resistant isolates.

Phylogeny and morphology of Ophiocordyceps puluongensis sp. nov. (Ophiocordycipitaceae, Hypocreales), a new fungal pathogen on termites from Vietnam.

Termites are serious pests in agriculture and forestry, causing significant economic losses to property and the construction industry. However, only a few entomopathogenic fungi attack termites that are dominant members of most terrestrial biomes. This study contributes to the taxonomic knowledge of entomopathogenic fungi with the description of a new pathogen on termites collected from the Pu Luong Nature Reserve in Vietnam. The new termite pathogen, Ophiocordyceps puluongensis, is introduced on the basis of morphological and multigene phylogenetic evidence. Based on the combined dataset of five genes including the nuclear ribosomal small and large subunits (nrSSU and nrLSU), the elongation factor 1α (tef-1α), and the largest and the second largest subunits of RNA polymerase II (rpb1 and rpb2), phylogenetic analyses were performed by Maximum Likelihood and Bayesian inference methods to determine the phylogenetic position of O. puluongensis. Three samples of O. puluongensis are clustered in the Hirsutella thompsonii subclade of Hirsutella lineages in Ophiocordyceps, and clustered together with O. asiatica to form a separate clade from other Ophiocordyceps species. Morphologically, O. puluongensis differs from O. asiatica by its smaller and shorter perithecia, asci and ascospores, pink to reddish-orange stipes of stromata, as well as smaller fusiform or citriform conidia. The distinctiveness of this termite pathogen is strongly supported by both molecular phylogeny and morphology. The entomopathogenic fungus O. puluongensis could have the potential to be used as bioinsecticides to control termites.