Three cases of vulvovaginal candidiasis due to Candida nivariensis.

Candida nivariensis is emerging as a highly resistant species of the Candida glabrata complex causing invasive and mucocutaneous infections. In this study, three cases of vulvovaginal candidiasis caused by C. nivariensis are described and identified by Internal Transcribed Spacer 1-2 sequencing. All isolates were susceptible in vitro to anidulafungin, micafungin, caspofungin, 5-flucytosine, posaconazole, voriconazole, itraconazole, amphotericin B, and showed dose-dependent susceptibility to fluconazole. In two patients, three doses of oral fluconazole were effective, while one patient developed clinical fluconazole resistance with a new relapse after 6 months. Increasing the weekly dose of fluconazole showed to be effective in this patient.

Azole non-susceptible C. tropicalis and polyclonal spread of C. albicans in Central Vietnam hospitals.

INTRODUCTION: Candida spp. are responsible for infections ranging from local to systemic, and resistance to antifungal first-line therapy is increasing in non-albicans Candida species. We aimed to determine the etiology of candidiasis and the antifungal resistance of Candida spp. isolated in Hue hospitals, Central-Vietnam. METHODS: Species identification was performed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry supported by fungal internal-transcribed-spacer amplification and sequencing. Antifungal susceptibility testing was performed by disk diffusion method and minimum inhibitory concentrations of azoles, caspofungin, and amphotericin B against C. tropicalis were determined by broth microdilution. Polymorphism of erg11 gene associated with fluconazole resistance was carried out by polymerase chain reaction and sequencing. Multilocus sequence typing (MLST) was used for typing selected C. albicans isolates. RESULTS: Overall, 196 Candida isolates were detected, mostly C. albicans (48%), followed by C. tropicalis (16%), C. parapsilosis (11%), C. glabrata (9%), C. orthopsilosis (6%) and to a lesser extent another eight species. High rates of resistance to fluconazole and voriconazole (18.8%) were observed in C. tropicalis with five isolates co-resistant to both agents. Y132F and S154F missense mutations in the ERG11 protein were associated with fluconazole-resistance in C. tropicalis (67.7%). Resistance to caspofungin was found in one isolate of C. albicans. MLST identified a polyclonal population of C. albicans with multiple diploid sequence types, and with few lineages showing potential nosocomial spread. CONCLUSIONS: Resistance to triazole agents should be considered in C. tropicalis infections in the studied hospitals, and surveillance measures taken to avoid Candida diffusion.

First detection of Trichophyton indotineae causing tinea corporis in Central Vietnam.

Trichophyton indotineae, a new species of dermatophytes, has become a significant concern in treating dermatophytosis due to the high level of terbinafine resistance reported in this organism. This is the first report of Trichophyton indotineae infection in Central Vietnam. Antifungal susceptibility testing showed that this isolate was susceptible to itraconazole, voriconazole, and terbinafine. Therefore, the patient was successfully treated with oral itraconazole and ketoconazole topical cream.

Nannizzia incurvata in Hue city - Viet Nam: Molecular identification and antifungal susceptibility testing.

BACKGROUND: Nannizzia incurvata, a species belonging to the Nannizzia gypsea complex, is considered a neglected pathogen. OBJECTIVE: To detected N. incurvata isolates from dermatophytosis patients in Hue city - Viet Nam, and test the antifungal susceptibility of this species. Moreover, fungal capability to produce hydrolytic enzymes was evaluated. METHODS: Patients' samples were collected and cultured on Sabouraud-chloramphenicol-cycloheximide medium. Dermatophytes isolates were initially macroscopically and microscopically identified. ITS PCR-RFLP and ITS rDNA sequences were performed to determine and confirm species. An ITS Neighbor-Joining phylogenetic tree evaluated the genetic relationship among isolates. Fungal hydrolytic enzymes were examined, including lipase, phospholipase and protease. Antifungal susceptibility testing was carried out by the disk diffusion method. MICs of itraconazole, voriconazole, and terbinafine against these isolates were determined by the broth microdilution method. RESULTS: Twelve isolates of N. gypsea complex were preliminary morphologically identified. PCR-RFLP and ITS-rDNA sequencing identified and confirmed dermatophytes as N. incurvata strains, respectively. An evident polymorphism among isolates was highlighted in the phylogenetic tree. All isolates showed the activity of lipase, phospholipase, and protease production. Overall, all N. incurvata isolates were susceptible to itraconazole, voriconazole, clotrimazole, miconazole, and terbinafine. Few isolates were susceptible to griseofulvin, and none of them were susceptible to fluconazole. CONCLUSIONS: There was a presence of polyclonal N. incurvata isolates in dermatophytosis patients from Hue city, identified by PCR-RLFP and confirmed by ITS sequencing. We confirmed PCR-RLFP as a reliable technique to identify this species. Azole and terbinafine are the optimal choices for N. incurvata treatment except for fluconazole.

A case of onychomycosis caused by a terbinafine-susceptible Fusarium solani in Vietnam.

Fusarium spp. are the common onychomycosis pathogens in non-dermatophyte molds, and are considered resistant to many antifungal agents. We reported onychomycosis of the fingernail caused by Fusarium solani in Vietnam. The minimum inhibitory concentration of terbinafine against the tested isolate was 1µg/ml, which was the lowest of all antimycotic agents. The patient was successfully treated with a daily dose of 250mg terbinafine for two months, and no recurrence occurred after a one-year follow-up. Antifungal susceptibility testing is recommended in Fusarium onychomycosis.