Molecular and antifungal susceptibility study on trichosporonemia and emergence ofTrichosporon mycotoxinivoransas a bloodstream pathogen

Abstract

A total of 21 Trichosporon spp. isolates from blood over a period of 5 years (January 2009 to December 2013) were included in the study. The most common underlying diseases found were pancreatitis (33.3%) and cancer (33.3%). Trichosporon asahii (80.9%) was the commonest species followed by Trichosporon mycotoxinivorans (14.2%) and Trichosporon faecale (4.7%). On IGS1 region sequencing the most predominant T. asahii type in our region was genotype 1 (16/17 isolates; 94.1%) and one isolate belonged to genotype 4. Following the interpretative breakpoints for Candida albicans according to CLSI guidelines amphotericin B minimum inhibitory concentrations (MICs) were ≤1 μg/ml for 38% of isolates. Fluconazole MICs were ≤4 μg/ml for 33.3% of the isolates. Itraconazole MICs were ≤0.5 μg/ml for 52.3% of the isolates. However, the MICs to posaconazole and voriconazole were ≤0.5 μg/ml for all the isolates. The MICs to caspofungin and micafungin were ≤0.5 μg/ml for only 0.09% of the isolates. This study reemphasizes that IGS1 sequencing is the most reliable technique for accurate identification of Trichosporon spp. and also to identify the newer species like T. mycotoxinivorans, which still remains rare. Surveillance of antifungal susceptibility patterns can provide the local drug resistance data to the clinicians which can further aid better management of patients.

Invasive Infections Due to Trichosporon : Species Distribution, Genotyping, and Antifungal Susceptibilities from a Multicenter Study in China

“…A noteworthy finding of our study is that only a limited number of Trichosporon isolates (10.5% [14/133 isolates]) were isolated from patients with hematological malignances, which were earlier reported to be one of the major underlying conditions (4, 5). Dabas et al also found that the incidence rate for Trichosporon bloodstream infections was lower in patients with malignancies than in those with gastrointestinal manifestations (22). In a study conducted by the Invasive Fungal Infection Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group in cancer patients (5,23), involving 30 centers and lasting 2 years, 269 cases of fungemia were reported but only 3 were caused by Trichosporon spp.…”

Evaluating and Improving Vitek MS for Identification of Clinically Relevant Species of Trichosporon and the Closely Related Genera Cutaneotrichosporon and Apiotrichum

“…mycotoxinivorans (formerly Trichosporon mycotoxinivorans) is now considered a relevant pathogen for patients with cystic fibrosis (16). Moreover, this microorganism has been related to deep-seated infections in immunocompromised patients with invasive disposals in India (17). The use of Bruker's MALDI-TOF MS as a reliable tool for A. mycotoxinivorans species identification has helped strengthen the epidemiologic link of T. mycotoxinivorans to cystic fibrosis (18,19).…”

Prevalence and Antifungal Susceptibility of Pathogenic Yeasts in China: A 10-Year Retrospective Study in a Teaching Hospital

“…A growing population of immunocompromised patients has resulted in frequent diagnoses of invasive fungal infections (IFIs), including those caused by unusual yeasts ( Dabas et al, 2017 ). Invasive candidiasis is a growing concern worldwide with high morbidity and mortality; it affects patients of all ages, including patients with malignancies, HIV-negative immunocompromised (IC) patients, and non-immunocompromised (NIC) patients among those who are critically ill, often admitted to an intensive care unit (ICU), or diagnosed with diabetes mellitus or uncontrolled hyperglycemia requiring invasive mechanical ventilation ( Berdal et al, 2014 ; Bitar et al, 2014 ; Epelbaum and Chasan, 2017 ; Alves et al, 2018 ; Ding et al, 2018 ; Mantadakis et al, 2018 ).…”