Emerging Nosocomial Trichosporon asahii in a Tertiary Hospital in Southern Saudi Arabia

Abstract

Background: Trichosporon species are pathogenic yeasts that colonize diverse human body sites and cause superficial in addition to invasive trichosporonosis, especially in immunosuppressed patients. The disease is an emerging health-care problem, as it has shown a noticeable increase in recent years. The leading risk factors are antibiotic use, invasive medical equipment, and chemotherapy. Informed evidence on the disease and its causal agent is needed. Objective: Presentation of clinical cases caused by Trichosporon sp. and identification of isolates recovered from various specimens in Aseer Central Hospital setting. Materials and Methods: The study analyzed fungal cultures (n = 20) from different clinical specimens submitted on a routine basis from hospital wards for general microbiological investigation at Aseer Central Hospital, Abha, Saudi Arabia (2021–2023). Mycologically proven trichosporonosis cases were initially identified by desktop methods, automated Vitek 2, and confirmed by sequence analysis of the ribosomal targets, namely the large-subunit RNA gene (D1–D2 region) and internal transcribed spacers 1 and 2 (ITS1 and ITS2 regions), patients were treated with fluconazole, and treatment outcomes were recorded. Results: Clinical features and culture results confirmed trichosporonosis caused by Trichosporon asahii with different clinical presentations. The majority of the cases were urinary tract (44%), followed by skin (28%) and respiratory tract (12%). All trichosporonosis cases responded to fluconazole. The neighbor-joining phylogenetic tree based on the rRNA regions and ITS and comparative analysis using GenBank reference data showed the association of our strains to the reference T. asahii clade, closely related to T. faecale and T. insectorum but different from other species. Conclusions: The study offered accurate species identification of the Trichosporon isolates by routine phenotypic tests as well as sequence-based techniques. Urinary tract infections were the most common manifestation of the infection, followed by skin and then respiratory tract infections. The cases of trichosporonosis responded well to fluconazole treatment. T. asahii is possibly underreported and should be considered in routine diagnostic investigations, notably in nosocomial infections.