Trichosporon asahii among intensive care unit patients at a medical center in Jamaica

A novel report on the emerging and zoonotic neurotropic fungus Trichosporon japonicum in the brain tissue of the endangered Brazilian guitarfish (Pseudobatos horkelii) off the southeastern coast of Brazil

Yeast infections have gained significant attention in the field of marine biology in recent years. Among the broad diversity of marine organisms affected by these infections, elasmobranchs (sharks and rays) have emerged as highly susceptible, due to climate change effects, such as increasing water temperatures and pollution, which can alter the composition and abundance of fungal communities. Additionally, injuries, or compromised immune systems resulting from pollution or disease may increase the likelihood of fungal infections in elasmobranchs. Studies are, however, still lacking for this taxonomic group. In this context, this study aimed to screen yeast species in cell cultures obtained from the brain of artisanally captured Pseudobatos horkelii, a cartilaginous fish that, although endangered, is highly captured and consumed worldwide. Fungi were isolated during an attempt to establish primary cultures of elasmobranch neural cells. Culture flasks were swabbed and investigated using morphological, phenotypic, and molecular techniques. Two isolates of the emerging opportunistic pathogen Trichosporon japonicum were identified, with high scores (1.80 and 1.85, respectively) by the MALDI-ToF technique. This is the first report of the basidiomycetous yeast T. japonicum in Pseudobatos horkelii in Brazil. This finding highlights the need for further research to determine the potential impact on elasmobranch health, ecology, as well as on commercial fisheries.

Case report: Diagnostic and therapeutic challenges of fungal endocarditis by Trichosporon asahii in a child with congenital heart defects

Background

patients with congenital cardiopathies are the main group at risk for infective endocarditis (IE) in the pediatric population. Fungal etiology is responsible for 2%-4% of all IEs, and the Trichosporon genus is an increasingly prevalent cause of infections in human beings.

Case presentation

We describe a 9-year-old male with multiple surgical procedures to correct congenital cardiopathy defects, including insertion of RV-PA conduit, who was admitted due to suspicion of pneumonia and needed a surgical approach after being diagnosed with a mycotic pseudoaneurysm in the right ventricle's outflow tract, with dilation of the RV-PA conduit. The conduit was removed and antifungal treatment was started with Voriconazole after the agent was identified (T. asahii), with satisfactory therapeutic response. Approximately 4 years later, the patient was readmitted, presenting with intermittent fever, associated with nocturnal diaphoresis, dry cough, anxiety and chest pain. Vegetations consistent with T. asahii were evidenced in the RV-PA conduit, and a surgical approach was once again necessary.

Discussion

diagnostic methods and treatment of T. asahii endocarditis aren't yet standardized, and recurrent surgical approaches are needed due to the inefficacy of antifungal treatment.

Epidemiology, clinical aspects, outcomes and prognostic factors associated with Trichosporon fungaemia: results of an international multicentre study carried out at 23 medical centres

BACKGROUND

Trichosporon fungaemia (TF) episodes have increased in recent years and mortality rates remain high despite the advances in the management of sepsis. New concepts about its clinical course, treatment and microbiology need to be investigated for the better management of this infection.

OBJECTIVES

To describe the aetiology, natural history, clinical management and prognostic factors of TF.

METHODS

TF episodes documented between 2005 and 2018 in 23 South American centres were retrospectively investigated by using a standard clinical form. Molecular identification, antifungal susceptibility testing and biofilm production were also performed.

RESULTS

Eighty-eight TF episodes were studied. Patients had several underlying conditions, including haematological diseases (47.7%), post-operative status (34%), solid organ transplants (n = 7, 7.9%), among others. Seventy-three (82.9%) patients had a central venous catheter (CVC) at TF diagnosis. The 30 day mortality rate was 51.1%. Voriconazole-based therapy was given to 34 patients (38.6%), with a 30 day mortality rate of 38.2%. Multivariate predictors of 30 day mortality were age (OR 1.036), mechanical ventilation (OR 8.25) and persistent neutropenia (OR 9.299). CVC removal was associated with over 75% decreased risk of 30 day mortality (OR 0.241). Microbiological analyses revealed that 77.7% of the strains were identified as Trichosporon asahii, and voriconazole showed the strongest in vitro activity against Trichosporon spp. Most of the strains (63%) were considered medium or high biofilm producers.

CONCLUSIONS

Older age, mechanical ventilation and persistent neutropenia were associated with poor prognosis. CVC may play a role in the pathogenicity of TF and its removal was associated with a better prognosis.

Trichosporon asahii superinfections in critically ill COVID-19 patients overexposed to antimicrobials and corticosteroids

Objectives

To investigate the occurrence of Trichosporon asahii fungemia among critically ill COVID‐19 patients.

Methods

From 1 July to 30 September 2020, cases of T asahii fungemia (TAF) in a Brazilian COVID‐19 referral centre were investigated. The epidemiology and clinical courses were detailed, along with a mycological investigation that included molecular species identification, haplotype diversity analysis and antifungal susceptibility testing.

Results

Five critically ill COVID‐19 patients developed TAF in the period. All five patients had common risk conditions for TAF: central venous catheter at fungemia, previous exposure to broad‐spectrum antibiotics, prior echinocandin therapy and previous prolonged corticosteroid therapy. The average time of intensive care unit hospitalisation previous to the TAF episode was 23 days. All but one patient had voriconazole therapy, and TAF 30‐day mortality was 80%. The five T asahii strains from the COVID‐19 patients belonged to 4 different haplotypes, mitigating the possibility of skin origin and cross‐transmission linking the 5 reported episodes. The antifungal susceptibility testing revealed low minimal inhibitory concentrations for azole derivatives.

Conclusions

Judicious prescription of antibiotics, corticosteroids and antifungals needs to be discussed in critically ill COVID‐19 patients to prevent infections by hard‐to‐treat fungi like T asahii.

Multidrug-resistant Trichosporon species: underestimated fungal pathogens posing imminent threats in clinical settings

Species of Trichosporon and related genera are widely used in biotechnology and, hence, many species have their genome sequenced. Importantly, yeasts of the genus Trichosporon have been increasingly identified as a cause of life-threatening invasive trichosporonosis (IT) in humans and are associated with an exceptionally high mortality rate. Trichosporon spp. are intrinsically resistant to frontline antifungal agents, which accounts for numerous reports of therapeutic failure when echinocandins are used to treat IT. Moreover, these fungi have low sensitivity to polyenes and azoles and, therefore, are potentially regarded as multidrug-resistant pathogens. However, despite the clinical importance of Trichosporon spp., our understanding of their antifungal resistance mechanisms is quite limited. Furthermore, antifungal susceptibility testing is not standardized, and there is a lack of interpretive epidemiological cut-off values for minimal inhibitory concentrations to distinguish non-wild type Trichosporon isolates. The route of infection remains obscure and detailed clinical and environmental studies are required to determine whether the Trichosporon infections are endogenous or exogenous in nature. Although our knowledge on effective IT treatments is rather limited and future randomized clinical trials are required to identify the best antifungal agent, the current paradigm advocates the use of voriconazole, removal of central venous catheters and recovery from neutropenia.

Emerging issues, challenges, and changing epidemiology of fungal disease outbreaks

Several high-profile outbreaks have drawn attention to invasive fungal infections (IFIs) as an increasingly important public health problem. IFI outbreaks are caused by many different fungal pathogens and are associated with numerous settings and sources. In the community, IFI outbreaks often occur among people without predisposing medical conditions and are frequently precipitated by environmental disruption. Health-care-associated IFI outbreaks have been linked to suboptimal hospital environmental conditions, transmission via health-care workers' hands, contaminated medical products, and transplantation of infected organs. Outbreak investigations provide important insights into the epidemiology of IFIs, uncover risk factors for infection, and identify opportunities for preventing similar events in the future. Well recognised challenges with IFI outbreak recognition, response, and prevention include the need for improved rapid diagnostic methods, the absence of routine surveillance for most IFIs, adherence to infection control practices, and health-care provider awareness. Additionally, IFI outbreak investigations have revealed several emerging issues, including new populations at risk because of travel or relocation, occupation, or immunosuppression; fungal pathogens appearing in geographical areas in which they have not been previously recognised; and contaminated compounded medications. This report highlights notable IFI outbreaks in the past decade, with an emphasis on these emerging challenges in the USA.

Pigeons and their droppings as reservoirs of Candida and other zoonotic yeasts

BACKGROUND

The importance of pigeons as reservoirs and carriers of Cryptococcus neoformans and other species of this genus is well-known; however, less is known about their role as reservoirs and carriers of other yeasts that impact public health.

AIMS

The present study was performed on Gran Canaria Island to define yeasts other than Cryptococcus spp. that have been reported to impact public health and which could be carried by pigeons.

METHODS

Samples were obtained from 83 pigeon lofts (Columba livia); moreover, 331 crop samples, 331 cloacal samples and 174 dropping samples were collected. In addition, 17 dropping samples were taken from a total of 17 public squares. Samples were inoculated on Sabouraud dextrose agar with chloramphenicol.

RESULTS

Different yeast species, i.e. Candida guilliermondii (24.36%), Candida kefyr (1.21%), Saccharomyces cerevisiae (2.43%), and Trichosporon asahii (1.21%) were isolated for the first time from the cloaca. The most frequently isolated yeast from the crop, cloaca and dropping samples from lofts was C. guilliermondii (30.46%, 24.36% and 49.37%, respectively). In addition, for the first time, C. kefyr (3.65%), Candida pelliculosa (2.43%), Candida rugosa (1.21%), T. asahii (3.65%), Trichosporon mucoides (3.65%) and Prototheca wickerhamii (1.21%) were obtained from crop samples; Candida pelliculosa (1.20%), T. asahii (9.63%) and T. mucoides (7.22%) were isolated from dropping samples in the lofts. Candida albicans was the most frequently isolated yeast in dropping samples collected in public squares.

CONCLUSIONS

It can be assumed that pigeons and their droppings act as carriers and reservoirs of Candida spp. and other zoonotic yeasts.

Invasive Trichosporon Infection: a Systematic Review on a Re-emerging Fungal Pathogen

Objectives: This review aimed to better depict the clinical features and address the issue of therapeutic management of Trichosporon deep-seated infections.

Methods: We comprehensively reviewed the cases of invasive Trichosporon infection reported in the literature from 1994 (date of taxonomic modification) to 2015. Data from antifungal susceptibility testing (AST) studies were also analyzed.

Results: Two hundred and three cases were retained and split into four groups: homeopathy (n = 79), other immunodeficiency conditions (n = 41), miscellaneous (n = 58) and newborns (n = 25). Trichosporon asahii was the main causative species (46.7%) and may exhibit cross-resistance to different antifungal classes. The unfavorable outcome rate was at 44.3%. By multivariate analysis, breakthrough infection (OR 2.45) was associated with unfavorable outcome, whilst the use of an azole-based therapy improved the prognosis (OR 0.16). Voriconazole-based treatment was associated with favorable outcome in hematological patients (73.6 vs. 41.8%; p = 0.016). Compiled data from AST demonstrated that (i) T. asahii exhibits the highest MICs to amphotericin B and (ii) voriconazole has the best in vitro efficacy against clinical isolates of Trichosporon spp.

Conclusions:Trichosporon infection is not only restricted to hematological patients. Analysis of compiled data from AST and clinical outcome support the use of voriconazole as first line therapy.

Estimated Burden of Serious Fungal Infections in Jamaica by Literature Review and Modelling

OBJECTIVE

Jamaica is one of the largest countries in the Caribbean with a population of 2 706 500. Prevalence of human immunodificency virus (HIV) in Jamaica is high, while that of tuberculosis (TB) is recorded to be low. In this study, we have estimated the burden of serious fungal infections and some other mycoses in Jamaica.

METHODS

All published papers reporting on rates of fungal infections in Jamaica and the Caribbean were identified through extensive search of the literature. We also extracted data from published papers on epidemiology and from the World Health Organization (WHO) TB Programme and UNAIDS. Chronic pulmonary aspergillosis (CPA), allergic bronchopulmonary aspergillosis (ABPA) and severe asthma with fungal sensitization (SAFS) rates were derived from asthma and TB rates. Where there were no available data on some mycoses, we used specific populations at risk and frequencies of fungal infection of each to estimate national prevalence.

RESULTS

Over 57 600 people in Jamaica probably suffer from serious fungal infections each year, most related to 'fungal asthma' (ABPA and SAFS), recurrent vulvovaginal candidiasis and AIDS-related opportunistic infections. Histoplasmosis is endemic in Jamaica, though only a few clinical cases are known. Pneumocystis pneumonia is frequent while cryptococcosis and aspergillosis are rarely recorded. Tinea capitis is common in children. Recurrent vulvovaginal candidiasis is very common (3154/100 000) and candidaemia occurs. Subcutaneous mycoses such as chromoblastomycosis and mycetoma also seem to be relatively common.

CONCLUSION

Local epidemiological studies are urgently required to validate or modify these estimates of serious fungal infections in Jamaica.