Rare opportunistic (non-Candida, non-Cryptococcus) yeast bloodstream infections in patients with cancer

Fungemia due to opportunistic fungi in patients with cancer

BACKGROUND

Fungemia due to uncommon fungi and secondary to multiple risk factors has become an emergent health problem, particularly in oncology patients.

AIMS

This study shows the following data collected during an 11-year period in a tertiary care oncologic center from patients with fungemia: demographic data, clinical characteristics, and outcome.

METHODS

A retrospective study was performed at Instituto Nacional de Cancerología, a 135-bed referral cancer center in Mexico City, from July 2012 to June 2023. All episodes of non-Candida fungemia were included.

RESULTS

Sixteen cases with uncommon fungemia were found in the database, representing 0.3% from all the blood cultures positive during the study period, and 8.5% from all the fungi isolated. The most common pathogens identified in our series were Histoplasma capsulatum, Acremonium spp., Trichosporon asahii, and Saccharomyces cerevisiae. Eight patients had hematologic malignancies, and five had severe neutropenia. In eight cases fungemia was considered catheter-related, in four cases was classified as primary, and in the last four it was diagnosed as disseminated fungal diseases. Mortality at 30 days was 43.8%.

CONCLUSIONS

The improved diagnostic tools have led to a better diagnosis of uncommon fungal infections. More aggressive therapeutic approaches, particularly in patients with malignancies, would increase survival rates in these potentially fatal diseases.

Invasive fungal infection caused by Blastobotrys mokoenaii in an immunocompromised patient with acute myeloid leukemia: A case report

Blastobotrys is a genus of rare yeast that is increasingly recognized as a cause of fungal infections in humans. However, there have been no reports of fungal infections in humans caused by Blastobotrys mokoenaii. We describe a case of invasive fungal infection (IFI) caused by B. mokoenaii in an immunocompromised patient with acute myeloid leukemia (AML). A 46-year-old man with relapsed/refractory AML underwent a second allogeneic peripheral blood hematopoietic stem cell transplantation (allo-PBSCT) during remission. The patient had prolonged neutropenia and received systemic steroid therapy for graft-versus-host disease before the second allo-PBSCT. Uncommon yeast was isolated from the blood cultures obtained on day 4. We initially suspected that the uncommon yeast was Trichosporon spp. based on its morphology. However, unlike Trichosporon spp., in vitro antifungal susceptibility tests showed that this yeast isolate was resistant to micafungin, caspofungin, voriconazole, itraconazole, and fluconazole. We performed DNA sequencing and identified it as B. mokoenaii. B. mokoenaii was persistently isolated from blood cultures taken during combination therapy with liposomal amphotericin B and voriconazole. The patient died of multiorgan failure on day 24. B. mokoenaii can cause severe IFI in immunocompromised patients; however, it may not be correctly identified by routine clinical microbiology testing in a hospital laboratory and DNA sequencing is useful for diagnosis.

Comparison of fungemia caused by Candida and non-Candida rare yeasts: a retrospective study from a tertiary care hospital

Although Candida species are the most common cause of fungemia, non-Candida rare yeasts (NCY) have been increasingly reported worldwide. Although the importance of these yeast infections is recognized, current epidemiological information about these pathogens is limited, and they have variable antifungal susceptibility profiles. In this study, we aimed to evaluate the clinical characteristics for fungemia caused by NCY by comparing with candidemia. The episodes of NCY fungemia between January 2011 and August 2023 were retrospectively evaluated in terms of clinical characteristics, predisposing factor, and outcome. In addition, a candidemia group, including patients in the same period was conducted for comparison. Antifungal susceptibility tests were performed according to the reference method. A total of 85 patients with fungemia episodes were included: 25 with NCY fungemia and 60 with candidemia. Fluconazole had high minimal inhibitory concentration (MIC) values against almost all NCY isolates. The MIC values for voriconazole, posaconazole, and amphotericin B were ≤ 2 µg/ml, and for caspofungin and anidulafungin were ≥ 1 µg/ml against most of isolates. Hematological malignancies, immunosuppressive therapy, neutropenia and prolonged neutropenia, polymicrobial bacteremia/fungemia, preexposure to antifungal drugs, and breakthrough fungemia were associated with NCY fungemia, whereas intensive care unit admission, diabetes mellitus, urinary catheters, and total parenteral nutrition were associated with candidemia. In conclusion, the majority of fungemia due to NCY species was the problem, particularly in hematology units and patients with hematological malignancy. Preexposure to antifungal drugs likely causes a change in the epidemiology of fungemia in favor of non-albicans Candida and/or NCY.

Emerging Fungal Pathogen Rhodotorula Species Isolated From a Patient With a Lung Malignancy

Rhodotorula is a genus of ubiquitous pigmented yeast found in the environment and as a commensal of human and animal microbiota. Previously considered nonpathogenic, Rhodotorula has emerged as an important cause of nosocomial and opportunistic infections in susceptible patients. While Rhodotorula spp. are common commensals in healthy individuals, the yeast may overgrow in patients with compromised immune systems causing disease. Herein, we provide a detailed presentation of a rare case involving a 79-year-old Caucasian female with a lung malignancy who developed massive cavitations in her lungs. The patient's lung tissue was cultured and grew an unidentified species of the genus Rhodotorula. The patient's health declined rapidly, and she expired due to hypoxemia. Clinicians must recognize patient groups potentially at risk for infection with Rhodotorula spp. Early identification and initiation of appropriate interventions are crucial in reducing mortality associated with this opportunistic fungal infection.

Differences of clinical characteristics and outcome in proven invasive Trichosporon infections caused by asahii and non-asahii species

BACKGROUND

Trichosporon is an emerging yeast that causes invasive infections in immunocompromised patients experiencing prolonged hospitalisation, indwelling venous catheters and neutropenia.

METHODS

This retrospective observational cohort study analysed invasive Trichosporon infections (ITIs) occurring between January 2005 and December 2022 at three tertiary hospitals and compared the clinical characteristics and prognostic factors of ITIs caused by Trichosporon asahii and non-T. asahii spp. After evaluating 1067 clinical isolates, we identified 46 patients with proven ITIs, defined as cases in which Trichosporon was isolated from blood, cerebrospinal fluid, or sterile tissues.

RESULTS

The patients were separated into T. asahii and non-T. asahii groups containing 25 and 21 patients, respectively, all of which except one were immunocompromised. During this period, both the number of clinical isolates and patients with ITIs (mainly T. asahii) increased; whereas, cases involving non-T. asahii spp. decreased. Compared with the non-T. asahii group, the T. asahii group had more patients with multiple catheters (84% vs. 33%, p = .001) and those receiving renal replacement therapy (48% vs. 14%, p = .005). The all-cause 28-day mortality rate after ITI in the T. asahii group (44%) was significantly higher than in the non-T. asahii group (10%, Log-rank p = .014). The multivariate Cox regression model revealed that T. asahii (reference, non-T. asahii spp.; aHR = 4.3; 95% CI = 1.2-15.2, p = .024) and neutropenia for 5 days or more (aHR = 2.2, 95% CI = 1.5-3.6, p = .035) were independent factors in the 28-day mortality after ITI.

CONCLUSION

The proven ITIs due to T. asahii produced more unfavourable outcomes compared with ITIs caused by non-T. asahii spp.

Geotrichosis: fungemia in a patient with acute lymphoblastic leukemia

Fungemia caused by Geotrichum spp. is rare and highly lethal. The Instituto Nacional de Cancerología in Bogotá reported just two cases: one in the period 2001-2007 and the other in 2012-2018. This type of infection is more common in any kind of immunocompromised patients, so it can occur in those with hematological malignancies. Here we present the case of a 27-year-old man, diagnosed with acute lymphoblastic leukemia in relapse and admitted with polyarthralgia for five days, febrile neutropenia, nonabscessed cellulitis, and bacteremia due to methicillin-sensitive Staphylococcus aureus. The patient received therapy with oxacillin and cefepime, but the febrile neutropenia persisted. A new set of blood cultures was taken, and antifungal treatment was started because of the suspicion of invasive fungal infection. Arthroconidia were identified in blood cultures and Geotrichum spp. was confirmed using matrix-assisted laser desorption-ionization mass spectrometry. The antifungal treatment was adjusted with amphotericin B deoxycholate for 14 days and voriconazole for four weeks, and after a prolonged stay, the patient was discharged. Although the incidence of fungemia caused by Geotrichum spp. is low, it must be considered in patients with hematological malignancies and persistent febrile neutropenia despite the broadspectrum antimicrobial treatment. The confirmation of fungemia causing agents, with proteomic tools such as the mentioned mass spectrometry, allows treatment adjustment and decreases complications, hospital stay, and mortality.

Fungemia due to rare non-Candida yeasts between 2018 and 2021 in a Greek tertiary care university hospital

INTRODUCTION

Non-Candida yeasts, although rare, are increasingly encountered and recognized as a growing threat.

METHODS

Cases of bloodstream infections (BSIs) due to non-Candida yeasts (NCYs) during the last four years (2018-2021) are presented.

RESULTS

During the study period, 16 cases caused by non-Candida yeasts out of 400 cases of yeast BSIs were recorded, corresponding to an incidence of 4%. Yeasts that were isolated included Cryptococcus spp (4 isolates-25%), Rhodotorula mucilaginosa (2 isolates-12.5%), Trichosporon asahii (7 isolates-43.75%) and Saccharomyces cerevisiae (3 isolates-18.75%). Predisposing factors involved mostly hematological malignancies, long term hospitalization or major surgical interventions. Most isolates, 15 out of 16 were susceptible to amphotericin B. Voriconazole was the most active azole in vitro. All isolates, except Saccharomyces spp., were resistant to echinocandins.

DISCUSSION

Early recognition of rare yeasts as causative agents of BSIs and prompt initiation of appropriate treatment based on current guidelines and expertise remain crucial in efficient patient management.

Rare Yeasts in Latin America: Uncommon Yet Meaningful

Systemic infections caused by rare yeasts are increasing given the rise in immunocompromised or seriously ill patients. Even though globally, the clinical significance of these emerging opportunistic yeasts is increasingly being recognized, less is known about the epidemiology of rare yeasts in Latin America. This review collects, analyzes, and contributes demographic and clinical data from 495 cases of infection caused by rare yeasts in the region. Among all cases, 32 species of rare yeasts, distributed in 12 genera, have been reported in 8 Latin American countries, with Trichosporon asahii (49.5%), Rhodotorula mucilaginosa (11.1%), and Saccharomyces cerevisiae (7.8%) the most common species found. Patients were mostly male (58.3%), from neonates to 84 years of age. Statistically, surgery and antibiotic use were associated with higher rates of Trichosporon infections, while central venous catheter, leukemia, and cancer were associated with higher rates of Rhodotorula infections. From all cases, fungemia was the predominant diagnosis (50.3%). Patients were mostly treated with amphotericin B (58.7%). Crude mortality was 40.8%, with a higher risk of death from fungemia and T. asahii infections. Culture was the main diagnostic methodology. Antifungal resistance to one or more drugs was reported in various species of rare yeasts.

Uncovering the Biotechnological Importance of Geotrichum candidum

Fungi make a fundamental contribution to several biotechnological processes, including brewing, winemaking, and the production of enzymes, organic acids, alcohols, antibiotics, and pharmaceuticals. The present review explores the biotechnological importance of the filamentous yeast-like fungus Geotrichum candidum, a ubiquitous species known for its use as a starter in the dairy industry. To uncover G. candidum's biotechnological role, we performed a search for related work through the scientific indexing internet services, Web of Science and Google Scholar. The following query was used: Geotrichum candidum, producing about 6500 scientific papers from 2017 to 2022. From these, approximately 150 that were associated with industrial applications of G. candidum were selected. Our analysis revealed that apart from its role as a starter in the dairy and brewing industries, this species has been administered as a probiotic nutritional supplement in fish, indicating improvements in developmental and immunological parameters. Strains of this species produce a plethora of biotechnologically important enzymes, including cellulases, β-glucanases, xylanases, lipases, proteases, and α-amylases. Moreover, strains that produce antimicrobial compounds and that are capable of bioremediation were identified. The findings of the present review demonstrate the importance of G. candidum for agrifood- and bio-industries and provide further insights into its potential future biotechnological roles.

Antifungal Activity of Plant Secondary Metabolites on Candida albicans: An Updated Review

Fungal infections have been increasing continuously worldwide, especially in immunocompromised individuals. Fungi, regarded as eukaryotic pathogens, have many similarities to the host cells, which inhibit anti-fungal drug development progress. Various fungal model systems have been studied, and it was concluded that Candida spp. is the most common disease-causing fungus. Candida species are well known to cause infections not only in our mouth, skin, and vagina, but they are also a frequent cause of life-threatening hospital bloodstream infections. The morphological and developmental pathways of Candida have been studied extensively, providing insight into the fungus development. Candida albicans is known to be the most pathogenic species responsible for a variety of infections in humans. Conventional anti-fungal drugs, mainly azoles drugs available in the market, have been used for years developing resistance in C. albicans. Hence, the production of new anti-fungal drugs, which require detailed molecular knowledge of fungal pathogenesis, needs to be encouraged. Therefore, this review targets the new approach of "Green Medicines" or the phytochemicals and their secondary metabolites as a source of novel anti-fungal agents to overcome the drug resistance of C. albicans, their mechanism of action, and their combined effects with the available anti-fungal drugs.

Clinical Challenges of Emerging and Re-Emerging Yeast Infections in the Context of the COVID-19 Pandemic

During the geological eras, some fungi, through adaptation and/or environmental/ecological pressure, interacted directly and indirectly with humans, through occasionally harmful interaction interdependent on the individual’s immunological condition. Infections caused by yeasts are underreported, subjugated, and underdiagnosed, and treatment is restricted to a few drugs, even after the significant progress of medicine and pharmacology. In the last centuries, antagonistically, there has been an exponential increase of immunocompromised individuals due to the use of immunosuppressive drugs such as corticosteroids, increased cases of transplants, chemotherapeutics, autoimmune diseases, neoplasms, and, more recently, coronavirus disease 2019 (COVID-19). This review aims to survey emerging and re-emerging yeast infections in the current clinical context. Currently, there is an immense clinical challenge for the rapid and correct diagnosis and treatment of systemic mycoses caused by yeasts due to the terrible increase in cases in the current context of COVID-19.

Asymptomatic Fungemia Due to Rhodotorula spp. Caused by a Subcutaneously Implanted Central Venous Port Catheter

A 66-year-old man was admitted to our hospital for gastrointestinal perforation. He had a history of surgery and chemotherapy for colorectal cancer and had a subcutaneously implanted central venous port catheter. After surgery for gastrointestinal tract perforation, he developed an intra-abdominal abscess, which was treated with broad-spectrum antimicrobial agents and improved. Following this improvement, Rhodotorula spp. was detected in a blood culture and at the catheter tip. He was asymptomatic despite having fungemia. His condition improved after the removal of the catheter and the administration of antifungal drugs. Fungemia due to Rhodotorula spp. is rare, and asymptomatic fungemia is even rarer.

Rhodotorula mucilaginosa Fungemia, a Rare Opportunistic Infection without Central Venous Catheter Implantation, Successfully Treated by Liposomal Amphotericin B

Background. Fungemia due to Rhodotorula mucilaginosa is rare and highly resistance to antifungal therapy. Since most cases of R. mucilaginosa fungemia are attributed to medical devices, limited information is currently available on infection without central venous catheter (CVC) implantation. We herein report a case of R. mucilaginosa fungemia without implantation of CVC, successfully treated by liposomal amphotericin B (L-AMB). Case Presentation. An 81-year-old man with a history of chronic obstructive lung disease and rheumatoid arthritis was admitted with dyspnea and fever. The present case had no previous history of CVC implantation. Candidemia was suspected based on yeast and salmon-pink colonies in blood cultures, and thus, micafungin (MCFG) was administered. The isolated yeast was identified as R. mucilaginosa, which exhibited resistance to MCFG. Therefore, antifungal therapy was changed to L-AMB. The sterile blood culture and defervescence were observed from the initiation of L-AMB. Conclusion. Although the obvious entry point was unclear, long-term immunosuppressive therapy for RA may have damaged the gastrointestinal tract, which leading to the bacterial translocation of R. mucilaginosa. An early class switch to L-AMB was effective. Physicians need to consider the administration of L-AMB in cases suspected of R. mucilaginosa fungemia following the detection of salmon-pink colonies in blood cultures.

Heme Oxygenase-1 (HMX1) Loss of Function Increases the In-Host Fitness of the Saccharomyces 'boulardii' Probiotic Yeast in a Mouse Fungemia Model

The use of yeast-containing probiotics is on the rise; however, these products occasionally cause fungal infections and possibly even fungemia among susceptible probiotic-treated patients. The incidence of such cases is probably underestimated, which is why it is important to delve deeper into the pathomechanism and the adaptive features of S. ‘boulardii’. Here in this study, the potential role of the gene heme oxygenase-1 (HMX1) in probiotic yeast bloodstream-derived infections was studied by generating marker-free HMX1 deletion mutants with CRISPR/Cas9 technology from both commercial and clinical S. ‘boulardii’ isolates. The six commercial and clinical yeasts used here represented closely related but different genetic backgrounds as revealed by comparative genomic analysis. We compared the wild-type isolates against deletion mutants for their tolerance of iron starvation, hemolytic activity, as well as kidney burden in immunosuppressed BALB/c mice after lateral tail vein injection. Our results reveal that the lack of HMX1 in S. ‘boulardii’ significantly (p < 0.0001) increases the kidney burden of the mice in most genetic backgrounds, while at the same time causes decreased growth in iron-deprived media in vitro. These findings indicate that even a single-gene loss-of-function mutation can, surprisingly, cause elevated fitness in the host during an opportunistic systemic infection. Our findings indicate that the safety assessment of S. ‘boulardii’ strains should not only take strain-to-strain variation into account, but also avoid extrapolating in vitro results to in vivo virulence factor determination.

Multiplex size marker (YEAST PLEX) for rapid and accurate identification of pathogenic yeasts

Background

Multiple yeast species can cause human disease, involving superficial to deep‐seated infections. Treatment of these infections depends on the accurate identification of causative agents; however, reliable methods are not available in many laboratories, especially not in resource‐limited settings. Here, a new multiplex assay for rapid and low‐cost identification of pathogenic yeasts is described.

Methods

A two‐step multiplex assay named YEAST PLEX that comprises of four tubes and identifies 17 clinically important common to rare yeasts was designed and evaluated. The set also provides PCR amplicon of unidentified species for direct sequencing. The specificity of YEAST PLEX was tested using 28 reference strains belonging to 17 species and 101 DNA samples of clinically important non‐target bacteria, parasites, and fungi as well as human genomic DNA. The method was further analyzed using 203 previously identified and 89 unknown clinical yeast isolates. Moreover, the method was tested for its ability to identify mixed yeast colonies by using 18 mixed suspensions of two or three species.

Results

YEAST PLEX was able to identify all the target species without any non‐specific PCR products. When compared to PCR‐sequencing/MALDI‐TOF, the results of YEAST PLEX were in 100% agreement. Regarding the 89 unknown clinical isolates, random isolates were selected and subjected to PCR‐sequencing. The results of sequencing were in agreement with those of YEAST PLEX. Furthermore, this method was able to correctly identify all yeasts in mixed suspensions.

Conclusion

YEAST PLEX is an accurate, low‐cost, and rapid method for identification of yeasts, with applicability, especially in developing countries.

Invasive Trichosporonosis in Neonates and Pediatric Patients with Malignancies or Hematologic Disorders

(1) Background: Trichosporon species have emerged as important opportunistic fungal pathogens, with Trichosporon asahii being the leading and most frequent cause of invasive disease. (2) Methods: We performed a global review focused on invasive trichosporonosis in neonates and pediatric patients with malignancies or hematologic disorders. We reviewed case reports and case series of trichosporonosis due to T. asahii published since 1994, the year of the revised taxonomic classification. (3) Results: Twenty-four cases of invasive trichosporonosis were identified in neonates with the presence of central venous catheter and use of broad-spectrum antibiotics recognized as the main predisposing factors. Thirty-two cases were identified in children with malignancies or hematologic disorders, predominantly with severe neutropenia. Trichosporon asahii was isolated from blood in 24/32 (75%) pediatric cases. Cutaneous involvement was frequently observed in invasive trichosporonosis. Micafungin was the most commonly used prophylactic agent (9/22; 41%). Ten patients receiving prophylactic echinocandins were identified with breakthrough infections. A favorable outcome was reported in 12/16 (75%) pediatric patients receiving targeted monotherapy with voriconazole or combined with liposomal amphotericin B. Overall mortality in neonates and children with malignancy was 67% and 60%, respectively. (4) Conclusions: Voriconazole is advocated for the treatment of invasive trichosporonosis given the intrinsic resistance to echinocandins and poor susceptibility to polyenes.

Factors associated with breakthrough fungemia caused by Candida, Trichosporon, or Fusarium species when the breakthrough fungemia developed in patients with hematological disorders

Limited data are available on breakthrough fungemia, defined as fungemia that develops on administration of antifungal agents, in patients with hematological disorders. We reviewed the medical and microbiological records of adult patients with hematological diseases who had breakthrough fungemia between January 2008 and July 2019 at Toranomon Hospital and Toranomon Hospital Kajigaya in Japan. A total of 121 cases of breakthrough fungemia were identified. Of the 121 cases, 83, 11, 5, and 22 were receiving micafungin, voriconazole, itraconazole, and liposomal amphotericin B, respectively, when the breakthrough occurred. Of the 121 causative breakthrough fungal strains, 96 were Candida species, and the rest were 13 cases of Trichosporon species, 7 of Fusarium species, 2 of Rhodotorula mucilaginosa, and 1 each of Cryptococcus neoformans, Exophiala dermatitidis, and Magnusiomyces capitatus. The crude 14-day mortality rate of breakthrough fungemia was 36%. Significant independent factors associated with the crude 14-day mortality were age ≥60 years (P=0.011), chronic renal failure (P=0.0087), septic shock (P<0.0001), steroid administration (P=0.0085), and liposomal amphotericin B breakthrough fungemia (P=0.0011). An absolute neutrophil count >500/μL was significantly more common in candidemia in the multivariate analysis(P＝0.0065), neutropenia and non-allogeneic hematopoietic stem cell transplant recipients were significantly more common in Trichosporon fungemia (P=0.036 and P=0.033, respectively), and voriconazole breakthrough fungemia and neutropenia were significantly more common in Fusarium fungemia (P=0.016 and P=0.016, respectively). The epidemiological and clinical characteristics of breakthrough fungemia of patients with hematological disorders were demonstrated. Some useful factors to predict candidemia, Trichosporon fungemia, and Fusarium fungemia were identified.

Bloodstream infections caused by Magnusiomyces capitatus and Magnusiomyces clavatus: epidemiological, clinical and microbiological features of two emerging yeast species

BACKGROUND

Magnusiomyces clavatus and Magnusiomyces capitatus are emerging yeasts with intrinsic resistance to many commonly used antifungal agents. Identification is difficult, and determination of susceptibility patterns with commercial and reference methods is equally challenging. For this reason, few data on invasive infections by Magnusiomyces spp. are available.

OBJECTIVES

To determine the epidemiology and susceptibility of Magnusiomyces isolates from bloodstream infections (BSI) isolated in Germany and Austria from 2001-2020.

METHODS

In seven institutions a total of 34 Magnusiomyces BSI were identified. Identification was done by ITS sequencing and MALDI-TOF MS. Antifungal susceptibility was determined by EUCAST broth microdilution and gradient tests.

RESULTS

Of the 34 isolates, M. clavatus was more common (N=24) compared to M. capitatus (N=10). BSI by Magnusiomyces spp. were more common in men (62%) and mostly occurred in patients with haemato-oncological malignancies (79%). The highest in vitro antifungal activity against M. clavatus/M. capitatus was observed for voriconazole (MIC₅₀ 0.03/0.125 mg/L), followed by posaconazole (MIC₅₀ 0.125/0.25 mg/L). M. clavatus isolates showed overall lower MICs compared to M. capitatus. With the exception of amphotericin B, low essential agreement between gradient test and microdilution was recorded for all antifungals (0-70%). Both species showed distinct morphologic traits on ChromAgar Orientation and Columbia blood agar, which can be used for differentiation if no MALDI-TOF or molecular identification is available.

CONCLUSION

Most BSI were caused by M. clavatus. The lowest MICs were recorded for voriconazole. Gradient tests demonstrated unacceptably low agreement and should preferably not be used for susceptibility testing of Magnusiomyces spp.

Global guideline for the diagnosis and management of rare yeast infections: an initiative of the ECMM in cooperation with ISHAM and ASM

Uncommon, or rare, yeast infections are on the rise given increasing numbers of patients who are immunocompromised or seriously ill. The major pathogens include those of the genera Geotrichum, Saprochaete, Magnusiomyces, and Trichosporon (ie, basidiomycetes) and Kodamaea, Malassezia, Pseudozyma (ie, now Moesziomyces or Dirkmeia), Rhodotorula, Saccharomyces, and Sporobolomyces (ie, ascomycetes). A considered approach to the complex, multidisciplinary management of infections that are caused by these pathogens is essential to optimising patient outcomes; however, management guidelines are either region-specific or require updating. In alignment with the One World-One Guideline initiative to incorporate regional differences, experts from diverse geographical regions analysed publications describing the epidemiology and management of the previously mentioned rare yeasts. This guideline summarises the consensus recommendations with regards to the diagnostic and therapeutic options for patients with these rare yeast infections, with the intent of providing practical assistance in clinical decision making. Because there is less clinical experience of patients with rare yeast infections and studies on these patients were not randomised, nor were groups compared, most recommendations are not robust in their validation but represent insights by use of expert opinions and in-vitro susceptibility results. In this Review, we report the key features of the epidemiology, diagnosis, antifungal susceptibility, and treatment outcomes of patients with Geotrichum, Saprochaete, Magnusiomyces, and Trichosporon spp infections.

Changing Epidemiology of Invasive Fungal Disease in Allogeneic Hematopoietic Stem Cell Transplantation

Invasive fungal disease (IFD) is a common cause of morbidity and mortality in patients with hematologic malignancies, especially among those undergoing allogeneic hematopoietic stem cell transplantation (HSCT). The epidemiology of IFD in HSCT patients has been evolving over the last decades, mainly in relation to changes in HSCT therapies such as antifungal prophylaxis. A progressive decrease in Candida albicans infection has been documented, alongside a progressive increase in infections caused by non-albicans Candida species, filamentous fungi, and/or multidrug-resistant fungi. Currently, the most frequent IFD is invasive aspergillosis. In some parts of the world, especially in north Central Europe, a high percentage of Aspergillus fumigatus isolates are azole-resistant. New diagnostic techniques have documented the existence of cryptic Aspergillus species with specific characteristics. An increase in mucormycosis and fusariosis diagnoses, as well as diagnoses of other rare fungi, have also been described. IFD epidemiology is likely to continue changing further due to both an increased use of mold-active antifungals and a lengthened survival of patients with HSCT that may result in hosts with weaker immune systems. Improvements in microbiology laboratories and the widespread use of molecular diagnostic tools will facilitate more precise descriptions of current IFD epidemiology. Additionally, rising resistance to antifungal drugs poses a major threat. In this scenario, knowledge of current epidemiology and accurate IFD diagnoses are mandatory in order to establish correct prophylaxis guidelines and appropriate early treatments.

Saprochaete clavata (Geotrichum clavatum) septicemia in a patient with multiple myeloma; An emerging case from Southeastern Turkey

Background and Purpose

Invasive fungal infections (IFI) are life-threatening and can be seen in immuno-compromised patients with malignancy, those who undergo chemotherapy, or transplant recipients. The Candida and Aspergillus species are the most common IFI agents; however, infections can also be caused by rare fungal species. This case report is about a bloodstream infection due to Saprochaete clavata (formerly known as Geotrichum clavatum) in a woman with multiple myeloma.

Case report

A 59-years-old woman suffered from fever, widespread rashes, and diarrhea after an autologous bone marrow transplantation. Peripheral blood cultures were taken from the patient and sent to the microbiology laboratory. Cultures grew white to cream-colored cottony colonies. Moreover, septate and branched hyphae and arthroconidia were seen under a microscope by lactophenol blue staining. The fungi colonies were identified by Maldi Biotyper 3. 1. (manufactured by Bruker Daltonics, USA) as S. clavata (G. clavatum) with a reliable score. Antifungal susceptibility test was carried out by the concentration gradient strip Etest method. Minimal inhibitory concentrations of Amphotericin B, fluconazole, voriconazole, posaconazole, and anidulafungin were determined as 4, 3, 0.125, 0.125, and &gt; 32 mg/dL, respectively. Despite amphotericin B treatment, the patient died three days after the identification of the fungi.

Conclusion

The IFIs are serious conditions that have high mortality rates. In the current case report, we aimed to draw attention to S. clavata which is a rare fungal agent.

Risk factors and biofilm formation analyses of hospital-acquired infection of Candida pelliculosa in a neonatal intensive care unit

Background

Candida pelliculosa is an ecological fungal species that can cause infections in immunocompromised individuals. Numerous studies globally have shown that C. pelliculosa infects neonates. An outbreak recently occurred in our neonatal intensive care unit; therefore, we aimed to evaluate the risk factors in this hospital-acquired fungal infection.

Methods

We performed a case-control study, analysing the potential risk factors for neonatal infections of C. pelliculosa so that infection prevention and control could be implemented in our units. Isolated strains were tested for drug resistance and biofilm formation, important factors for fungal transmission that give rise to hospital-acquired infections.

Results

The use of three or more broad-spectrum antimicrobials or long hospital stays were associated with higher likelihoods of infection with C. pelliculosa. The fungus was not identified on the hands of healthcare workers or in the environment. All fungal isolates were susceptible to anti-fungal medications, and after anti-fungal treatment, all infected patients recovered. Strict infection prevention and control procedures efficiently suppressed infection transmission. Intact adhesin-encoding genes, shown by genome analysis, indicated possible routes for fungal transmission.

Conclusions

The use of three or more broad-spectrum antimicrobials or a lengthy hospital stay is theoretically associated with the risk of infection with C. pelliculosa. Strains that we isolated are susceptible to anti-fungal medications, and these were eliminated by treating all patients with an antifungal. Transmission is likely via adhesion to the cell surface and biofilm formation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06295-1.

Infrared Spectroscopy of Blood

The magnitude of infectious diseases in the twenty-first century created an urgent need for point-of-care diagnostics. Critical shortages in reagents and testing kits have had a large impact on the ability to test patients with a suspected parasitic, bacteria, fungal, and viral infections. New point-of-care tests need to be highly sensitive, specific, and easy to use and provide results in rapid time. Infrared spectroscopy, coupled to multivariate and machine learning algorithms, has the potential to meet this unmet demand requiring minimal sample preparation to detect both pathogenic infectious agents and chronic disease markers in blood. This focal point article will highlight the application of Fourier transform infrared spectroscopy to detect disease markers in blood focusing principally on parasites, bacteria, viruses, cancer markers, and important analytes indicative of disease. Methodologies and state-of-the-art approaches will be reported and potential confounding variables in blood analysis identified. The article provides an up to date review of the literature on blood diagnosis using infrared spectroscopy highlighting the recent advances in this burgeoning field.

Clinical Characteristics and Outcomes of Breakthrough Candidemia in 71 Hematologic Malignancy Patients and/or Allogeneic Hematopoietic Stem Cell Transplant Recipients: A Single-center Retrospective Study From China, 2011-2018

BACKGROUND

Antifungal prophylaxis may result in breakthrough infections in hematology patients with severe agranulocytosis, with few studies assessing risk factors and clinical outcomes of breakthrough candidemia. We described the distribution of Candida species, assessed risk factors for mortality in such patients, and determined differences in the incidence and mortality of breakthrough candidemia between patients who did or did not receive an allogeneic hematopoietic stem cell transplant.

METHODS

We collected clinical and microbiological data of patients with hematologic malignancies and breakthrough candidemia from a single center. Seven-day and 30-day follow-up outcomes were recorded; the incidence and mortality of breakthrough candidemia between patients who did or did not undergo an allogeneic transplant were compared. Kaplan-Meier survival estimates were used to generate survival curves, and predictors were identified using Cox regression analyses.

RESULTS

Of 71 enrolled patients, 17 received allogeneic transplants. Incidences of breakthrough candidemia were 17 of 2924 (0.58%) and 54 of 12 015 (0.45%) in the transplant and nontransplant groups, respectively (P = .35). The most common isolate was Candida tropicalis, and antifungal agent combinations were the most common first-line treatment. Cumulative mortality rates of patients were 21.1% and 31.0% at days 7 and 30, respectively, and they significantly differed between both groups. Septic shock, central venous catheter removal, and granulocyte recovery were significantly associated with 7-day mortality; the latter 2 remained independent predictors of 30-day mortality.

CONCLUSIONS

Breakthrough candidemia-related mortality was higher in the allogeneic transplant group, although the incidence was not significantly different between the groups. Prompt and adequate antifungal treatment with catheter removal may reduce mortality.

How I perform hematopoietic stem cell transplantation on patients with a history of invasive fungal disease

Hematopoietic transplantation is the preferred treatment for many patients with hematologic malignancies. Some patients may develop invasive fungal diseases (IFDs) during initial chemotherapy, which need to be considered when assessing patients for transplantation and treatment posttransplantation. Given the associated high risk of relapse and mortality in the post-hematopoietic stem cell transplantation (HSCT) period, IFDs, especially invasive mold diseases, were historically considered a contraindication for HSCT. Over the last 3 decades, advances in antifungal drugs and early diagnosis have improved IFD outcomes, and HSCT in patients with a recent IFD has become increasingly common. However, an organized approach for performing transplantation in patients with a prior IFD is scarce, and decisions are highly individualized. Patient-, malignancy-, transplantation procedure-, antifungal treatment-, and fungus-specific issues affect the risk of IFD relapse. Effective surveillance to detect IFD relapse post-HSCT and careful drug selection for antifungal prophylaxis are of paramount importance. Antifungal drugs have their own toxicities and interact with immunosuppressive drugs such as calcineurin inhibitors. Immune adjunct cytokine or cellular therapy and surgery can be considered in selected cases. In this review, we critically evaluate these factors and provide guidance for the complex decision making involved in the peri-HSCT management of these patients.

Histopathological study on the prevalence of trichosporonosis in formalin-fixed and paraffin-embedded tissue autopsy sections by in situ hybridization with peptide nucleic acid probe

Trichosporon species are some of the most common pathogenic yeasts in Asia, and many are resistant to echinocandin antifungal drugs. Effective treatment of fungal infections requires the selection of appropriate antifungals and the accurate identification of the causal organism. However, in histopathological specimens Trichosporon spp. are often misidentified as Candida species due to morphological similarities. In situ hybridization (ISH) is a useful technique for identifying fungal species in formalin-fixed and paraffin-embedded (FFPE) tissue sections. Although many novel probes for ISH are available, the practical use of ISH for identification of fungi remains limited, in part due to the lack of adequate verifications. We conducted a two-center retrospective observational study in which the ISH technique was used to differentiate Trichosporon spp. and C. albicans in FFPE tissue from autopsy specimens. The study included 88 cases with blood stream yeast infection without Cryptococci extracted from 459 autopsy files of cases with proven invasive fungal infection (IFI). Positive signals for the Trichosporon spp. protein nucleic acid (PNA) probe and C. albicans PNA probe were seen for 7 and 35 cases, respectively, whereas the remaining 46 were negative for both. For the Trichosporon spp.- positive specimens, 5/7 were reported as candidiasis in autopsy records. Our results suggested that accurate histological identification of fungal infections remains challenging, but ISH may be a suitable approach to support histological findings. In addition, this retrospective study suggested that trichosporonosis may have high prevalence among cases of bloodstream yeast infections in Japan.

Wickerhamomyces anomalous: A Rare Cause of Fungemia Causing Febrile Neutropenia in Acute Lymphoblastic Leukemia

Candida bloodstream infection is the major cause of increased morbidity and mortality (20-49%) in hospitalized patients in both paediatric and adult age groups. Due to the increase in the number of immunocompromised patients, other important species such as Trichosporon asahii and Debaryomyces hansenii are emerging. One such organism, Wickerhamomyces anomalous, previously known as Pichia anomala (teleomorph stages of several Candida species), is increasingly being reported as a cause of fungemia in neonatal intensive care units and is now increasingly being reported in a lot of immunosuppressive conditions such as interstitial lung disease, endocarditis, enteritis, corticosteroids, and chemotherapy uptake. Though this yeast is ubiquitous in nature, systemic infections from isolated cases and sporadic outbreaks with high mortality have been reported in ICUs, which emphasize the importance to consider this fungus within the diagnostic possibilities. Here, we report a case of catheter-related bloodstream infection (CRBSI) caused by W. anomalus in a leukemic immunosuppressed patient who was successfully treated by early detection and treatment of this emerging fungus.

Fatal Case of Fungemia by Wickerhamomyces anomalus in a Pediatric Patient Diagnosed in a Teaching Hospital from Brazil

In recent decades, emerging fungal infections have changed the clinical mycology scenario as a consequence of the advances in medical diagnostics and therapeutic procedures, long hospitalization times, and the growing number of individuals with debilitating chronic diseases and impaired immune systems. This report presents a 19 months old Brazilian female patient who developed a severe fungal sepsis by an uncommon yeast. She was admitted at the intensive care unit with severe pneumonia, bronchopulmonary dysplasia, and weight-for-age z score of less than −2. She remained more than 30 days in the intensive care unit where she had a femoral venous catheter placement, enteral nutrition, broad-spectrum antibiotic therapy, and prophylaxis with fluconazole. Moreover, pericardiocentesis was performed due to cardiac tamponade. She had a previous history of prematurity, cardiac surgery due to patent ductus arteriosus, and a long period of hospital stay. Despite the antifungal prophylaxis, two yeast isolates were recovered from blood and then identified by classical mycological methods and internal transcribed spacer (ITS) sequencing as Wickerhamomyces anomalus. Both isolates exhibited susceptibility to amphotericin B, ketoconazole, itraconazole, voriconazole, and fluconazole. Her clinical state worsened, presenting anasarca, epistaxis, and hemorrhagic suffusions in the mouth, sclera, oliguria, and bradycardia. Two days after the first positive culture, she presented a gradual reduction of the white blood cells count, with severe leukopenia and neutropenia. She died five days after.

Make Sure You Have a Safety Net: Updates in the Prevention and Management of Infectious Complications in Stem Cell Transplant Recipients

Hematopoietic stem cell transplant recipients are at increased risk of infection and immune dysregulation due to reception of cytotoxic chemotherapy; development of graft versus host disease, which necessitates treatment with immunosuppressive medications; and placement of invasive catheters. The prevention and management of infections in these vulnerable hosts is of utmost importance and a key “safety net” in stem cell transplantation. In this review, we provide updates on the prevention and management of CMV infection; invasive fungal infections; bacterial infections; Clostridium difficile infection; and EBV, HHV-6, adenovirus and BK infections. We discuss novel drugs, such as letermovir, isavuconazole, meropenem-vaborbactam and bezlotoxumab; weigh the pros and cons of using fluoroquinolone prophylaxis during neutropenia after stem cell transplantation; and provide updates on important viral infections after hematopoietic stem cell transplant (HSCT). Optimizing the prevention and management of infectious diseases by using the best available evidence will contribute to better outcomes for stem cell transplant recipients, and provide the best possible “safety net” for these immunocompromised hosts.

Fungaemia due to rare yeasts in a tertiary care university centre within 18 years

BACKGROUND

Fungaemia due to rare yeasts has been recognised as an emerging, clinically relevant, but less investigated condition. Intrinsic resistance or reduced susceptibility of these species to echinocandins or fluconazole remains as a challenge in empirical treatment.

OBJECTIVES

To describe the clinical characteristics, administered antifungal agents, outcomes of patients with rare yeasts other than Candida (RY-OTC) fungaemia and determine the antifungal susceptibility profiles of the isolates.

PATIENTS AND METHODS

RY-OTC fungaemia between January-2001 and December-2018 were retrospectively evaluated. Antifungal susceptibility tests were performed according to CLSI M27-A3.

RESULTS

We identified 19 patients with fungaemia due to 20 RY-OTC (8 Trichosporon asahii, 4 Cryptococcus neoformans, 4 Saprochaete capitata, 3 Rhodotorula mucilaginosa, 1 Trichosporon mucoides) with an incidence of 2.2% among 859 fungaemia episodes. Haematological malignancy was the most common (42%) underlying disorder. In 6 patients, RY-OTC fungaemia developed as breakthrough infection while receiving echinocandins, amphotericin B or fluconazole. Amphotericin B, fluconazole or voriconazole were the drugs of choice for the initial treatment of breakthrough fungaemia. Among patients without previous exposure to antifungals, the most common empirical treatment was an echinocandin (50%), followed by fluconazole (42%) and amphotericin B (8%). Overall mortality was 47%. Worse outcome was most common among patients receiving echinocandins (83% vs 25%, P < .05). Voriconazole and posaconazole showed the highest in vitro activity against all the isolates tested. Amphotericin B MICs were relatively higher and the degree of activity of fluconazole and itraconazole was variable.

CONCLUSIONS

Early recognition of RY-OTC and knowledge about their susceptibility patterns remain crucial in initial treatment pending susceptibility data of isolates.

Saprochaete clavata infections in patients undergoing treatment for haematological malignancies: A report of a monocentric outbreak and review of the literature

Saprochaete clavata is a rare cause of fungaemia with deep organ involvement in patients with haematological malignancies with reported mortality rates of 60%-80%. We describe four cases of S clavata infection in a haematology unit over several months that were treated with voriconazole-based regimens. We also review the literature on factors that could contribute to earlier recognition and effective treatment of S clavata. We included all cases of culture-positive S clavata from sterile sites with associated signs of infection in patients undergoing treatment for a haematological malignancy. Isolates were identified by MALDI-TOF MS, and spectrum profiles were used to prepare clustering analysis of isolates. Susceptibility testing was performed using a commercial microtitre methods. Saprochaete clavata was isolated from the bloodstream in three cases and bronchial alveolar lavage (BAL) fluid in one case. Clustering analysis suggested strains of S clavata were clonal without evidence of divergence although a common source was not identified. Susceptibility testing yielded elevated MICs to fluconazole (8 mg/L) and echinocandins (>1-8 mg/L). All patients were treated with voriconazole-based regimens resulting in survival of 3/4 patients, who continued chemotherapy for their underlying malignancy without evidence of relapse. Saprochaete clavata is a rare but aggressive cause of breakthrough yeast infection in patients undergoing treatment for haematological malignancies, particularly patients with a prior history of echinocandin treatment. Timely initiation of appropriate treatment, aided by more rapid identification in microbiology laboratory, can reduce the risk of deep organ dissemination and patient death.

Ctt1 catalase activity potentiates antifungal azoles in the emerging opportunistic pathogen Saccharomyces cerevisiae

Fungi respond to antifungal drugs by increasing their antioxidant stress response. How this impacts antifungal efficacy remains controversial and not well understood. Here we examine the role of catalase activity in the resistance of Saccharomyces cerevisiae to the common antifungals, fluconazole and miconazole, for which we report minimum inhibitory concentrations (MICs) of 104 and 19 μM, respectively. At sub-MIC concentrations, fluconazole and miconazole stimulate catalase activity 2-3-fold but, unexpectedly, deletion of cytosolic catalase (ctt1) makes cells more resistant to these azoles and to clotrimazole, itraconazole and posaconazole. On the other hand, upregulating Ctt1 activity by preconditioning with 0.2 mM H₂O₂ potentiates miconazole 32-fold and fluconazole 4-fold. Since H₂O₂ preconditioning does not alter the resistance of ctt1Δ cells, which possess negligible catalase activity, we link azole potentiation with Ctt1 upregulation. In contrast, sod2Δ cells deleted for mitochondrial superoxide dismutase are 4–8-fold more azole sensitive than wild-type cells, revealing that Sod2 activity protects cells against azole toxicity. In fact, the ctt1Δ mutant has double the Sod2 activity of wild-type cells so ctt1 deletion increases azole resistance in part by Sod2 upregulation. Notably, deletion of peroxisomal/mitochondrial cta1 or cytosolic sod1 does not alter fluconazole or miconazole potency.

In vitro virulence determinants, comparative pathogenicity of Diutina (Candida) mesorugosa clinical isolates and literature review of the D. rugosa complex

Opportunistic mycoses by yeasts have increased considerably in the last three decades. Although Candida albicans is considered one of the most important causes of nosocomial infections, there is a recent shift to non-albicans Candida species as the most frequently isolated yeasts in particular risk groups. Diutina rugosa (formerly Candida rugosa) is a complex that includes four species: D. rugosa sensu stricto, D. neorugosa, D. pseudorugosa, and D. mesorugosa, and they are estimated to represent 0.2% of all Candida clinical isolates. In this study, we analyze nine clinical isolates of D. mesorugosa with focus on the virulence determinants and pathogenicity of the species by means of a Galleria mellonella survival model. Overall, we detected very strong aspartyl-protease and esterase activities. In contrast, both DNase and hemolysin activities were evident in only two of the isolates. None of the isolates was positive for phospholipase activity. All isolates studied were able to form biofilm after 72 h of incubation in a robust manner when compared with the C. albicans strain used as control. Susceptibility testing showed minimum inhibitory concentrations (MICs) ≤1 µg/mL for amphotericin B in all isolates tested. Eight out of nine of the isolates had MICs ≤2 µg/mL for fluconazole. All isolates were resistant to both anidulafungin and caspofungin (MICs ≥1 µg/mL). We found a significant difference (P < 0.0001) amongst the survival curves for the different D. mesorugosa isolates in the Galleria mellonella survival model. Strains HPM309 and H259 produced an acute infection and exhibited the highest virulence, whereas the D. mesorugosa isolates 99-480 and DM17 proved to be the less virulent strains.

Impacts and Challenges of Advanced Diagnostic Assays for Transplant Infectious Diseases

The advanced technologies described in this chapter should allow for full inventories to be made of bacterial genes, their time- and place-dependent expression, and the resulting proteins as well as their outcome metabolites. The evolution of these molecular technologies will continue, not only in the microbial pathogens but also in the context of host-pathogen interactions targeting human genomics and transcriptomics. Their performance characteristics and limitations must be clearly understood by both laboratory personnel and clinicians to ensure proper utilization and interpretation.

Risk factors and clinical outcomes of breakthrough yeast bloodstream infections in patients with hematological malignancies in the era of newer antifungal agents

Although yeast bloodstream infections (BSIs) are increasingly being reported in patients with hematological malignancies undergoing antifungal therapy, clinical information regarding breakthrough infections is scarce. The aim of this study was to determine the risk factors for and clinical outcomes of breakthrough yeast BSIs in patients with hematological malignancies in the era of newer antifungal agents. Between 2011 and 2014, all consecutive patients with hematological malignancies who developed yeast BSIs were included in a case-control study wherein breakthrough infections (cases) and de novo infections (controls) were compared. Of 49 patients with yeast BSIs, 21 (43%) met the criteria for breakthrough infections. The proportions of Candida krusei and Candida tropicalis in the cases and controls were significantly different (32% [7/22] vs. 3% [1/29], P = .015; 5% [1/22] vs. 38% [11/29], P = .007, respectively). Acute leukemia, presence of a central venous catheter and neutropenia in the 3 days prior to BSI were significant risk factors for breakthrough infections. Six-week mortality rates was 33% [7/21] in the cases and 43% [12/28] in the controls (P = .564). Refractory neutropenia and the Pitt bacteremia score were independent predictors of 6-week mortality. In conclusion, breakthrough infections accounted for a significant proportion of yeast BSIs in patients with hematological malignancies. However, these infections did not increase the risk of death by themselves. Our results suggest that current clinical management of breakthrough yeast BSIs, which includes switching to a different antifungal class and prompt catheter removal is reasonable.

The epidemiology of non-Candida yeast isolated from blood: The Asia Surveillance Study

Background

Current guidelines recommend echinocandins as first‐line therapy for candidemia. However, several non‐Candida yeast are non‐susceptible to echinocandins (echinocandin non‐susceptible yeast, ENSY), including Cryptococcus, Geotrichum, Malassezia, Pseudozyma, Rhodotorula, Saprochaete, Sporobolomyces and Trichosporon. In laboratories that are not equipped with rapid diagnostic tools, it often takes several days to identify yeast, and this may lead to inappropriate presumptive use of echinocandins in patients with ENSY fungemia. The aim of this study was to determine the distribution of ENSY species during a 1‐year, laboratory surveillance programme in Asia.

Methods

Non‐duplicate yeast isolated from blood or bone marrow cultures at 25 hospitals in China, Hong Kong, India, Singapore, Taiwan and Thailand were analysed. Isolates were considered to be duplicative if they were obtained within 7 days from the same patient.

Results

Of 2155 yeast isolates evaluated, 175 (8.1%) were non‐Candida yeast. The majority of non‐Candida yeast were ENSY (146/175, 83.4%). These included Cryptococcus (109 isolates), Trichosporon (23), Rhodotorula (10) and Malassezia (4). The proportion of ENSY isolates (146/2155, 6.7%) differed between tropical (India, Thailand and Singapore; 51/593, 8.6%) and non‐tropical countries/regions (China, Hong Kong and Taiwan; 95/1562, 6.1%, P = 0.038). ENSY was common in outpatient clinics (25.0%) and emergency departments (17.8%) but rare in intensive care units (4.7%) and in haematology‐oncology units (2.9%). Cryptococcus accounted for the majority of the non‐Candida species in emergency departments (21/24, 87.5%) and outpatient clinics (4/5, 80.0%).

Conclusions

Isolation of non‐Candida yeast from blood cultures was not rare, and the frequency varied among medical units and countries.

Yeasts and filamentous fungi in psittacidae and birds of prey droppings in midwest region of Brazil: a potential hazard to human health

Birds of prey and from Psittacidae family are host to fungal microbiota and play an important role in the epidemiology of zoonoses. Few studies in the literature have characterized mycelial and yeast fungi in the droppings of these birds and correlated the isolates with the zoonotic potential of the microorganisms. Droppings from 149 birds were evaluated and divided into two groups: captive: Rhea americana araneipes, Primolius maracana, Ara ararauna, Ara chloropterus, Anodorhynchus hyacinthinus, Amazona aestiva, Ara macao macao, Ramphastos toco, Sarcoramphus papa, Busarellus nigricollis, Bubo virginianus nacurutu, Buteogallus coronatus, Buteogallus urubitinga urubitinga, Spizaetus melanoleucus, Spizaetus ornatus ornatus, Buteo albonotatus, Geranoaetus albicaudatus albicaudatus, Rupornis magnirostris magnirostris and Harpia harpyja, and quarantined birds: Amazona aestiva and Eupsitulla aurea. The fungal isolates were identified according to macroscopic (gross colony appearance), micromorphological and biochemical characteristics. Among birds displayed in enclosures, Aspergillus niger (41.1%) and Candida kefyr (63.8%) were the fungi most frequently isolated in Harpia harpyja and Ramphastos toco, respectively. For quarantined birds, the following percentages were observed in Eupsittula aurea , (76.6%) C. krusei, (84.4%) C. kefyr and (15.2%) C. famata, while in Amazona aestiva, (76.2%) C. krusei was observed. These findings indicate potentially pathogenic species in the bird droppings assessed, which constitute a risk of exposure for keepers and individuals who visit the zoo. Birds of the Cerrado and Pantanal of Mato Grosso (Central Western region of Brazil) could act in the epidemiological chain of important zoonoses.

Tracing the De Novo Origin of Protein-Coding Genes in Yeast

De novo genes are very important for evolutionary innovation. However, how these genes originate and spread remains largely unknown. To better understand this, we rigorously searched for de novo genes in Saccharomyces cerevisiae S288C and examined their spread and fixation in the population. Here, we identified 84 de novo genes in S. cerevisiae S288C since the divergence with their sister groups. Transcriptome and ribosome profiling data revealed at least 8 (10%) and 28 (33%) de novo genes being expressed and translated only under specific conditions, respectively. DNA microarray data, based on 2-fold change, showed that 87% of the de novo genes are regulated during various biological processes, such as nutrient utilization and sporulation. Our comparative and evolutionary analyses further revealed that some factors, including single nucleotide polymorphism (SNP)/indel mutation, high GC content, and DNA shuffling, contribute to the birth of de novo genes, while domestication and natural selection drive the spread and fixation of these genes. Finally, we also provide evidence suggesting the possible parallel origin of a de novo gene between S. cerevisiae and Saccharomyces paradoxus. Together, our study provides several new insights into the origin and spread of de novo genes.

Emergence of de novo genes has occurred in many lineages during evolution, but the birth, spread, and function of these genes remain unresolved. Here we have searched for de novo genes from Saccharomyces cerevisiae S288C using rigorous methods, which reduced the effects of bad annotation and genomic gaps on the identification of de novo genes. Through this analysis, we have found 84 new genes originating de novo from previously noncoding regions, 87% of which are very likely involved in various biological processes. We noticed that 10% and 33% of de novo genes were only expressed and translated under specific conditions, therefore, verification of de novo genes through transcriptome and ribosome profiling, especially from limited expression data, may underestimate the number of bona fide new genes. We further show that SNP/indel mutation, high GC content, and DNA shuffling could be involved in the birth of de novo genes, while domestication and natural selection drive the spread and fixation of these genes. Finally, we provide evidence suggesting the possible parallel origin of a new gene.

Micafungin Breakthrough Fungemia in Patients with Hematological Disorders

Limited data are available on micafungin breakthrough fungemia (MBF), fungemia that develops on administration of micafungin, in patients with hematological disorders. We reviewed medical and microbiological records of patients with hematological disorders who developed MBF between January 2008 and June 2015. A total of 39 patients with MBF were identified, and Candida (30 strains) and non-Candida (9 strains) fungal species were recognized as causative strains. Among 35 stored strains, Candida parapsilosis (14 strains), Trichosporon asahii (7 strains), Candida glabrata (5 strains), and other fungal species (9 strains) were identified by sequencing. Neutropenia was identified as an independent predictor of non-Candida fungemia (P = 0.023). T. asahii was the most common causative strain (7/19) during neutropenia. The 14-day crude mortality rate of patients treated with early micafungin change (EMC) to other antifungal agents was lower than that of the patients not treated with EMC (14% versus 43%, P = 0.044). Most of the stored causative Candida strains were susceptible (80%) or showed wild-type susceptibility (72%) to micafungin. The MICs of voriconazole for T. asahii were low (range, 0.015 to 0.12 μg/ml), whereas the MICs of amphotericin B for T. asahii were high (range, 2 to 4 μg/ml). MBF caused by non-Candida fungus should be considered, especially in patients with neutropenia. EMC could improve early mortality. Based on epidemiology and drug susceptibility profiling, empirical voriconazole-containing therapy might be suitable for treating MBF during neutropenia to cover for T. asahii.

Performance of VITEK mass spectrometry V3.0 for rapid identification of clinical Aspergillus fumigatus in different culture conditions based on ribosomal proteins

Fast and accurate discrimination of Aspergillus fumigatus is significant, since misidentification may lead to inappropriate clinical therapy. This study assessed VITEK mass spectrometry (MS) V3.0 for A. fumigatus identification using extracted fungal ribosomal proteins. A total of 52 isolates preliminarily identified as A. fumigatus by traditional morphological methods were inoculated in three different culture media and cultured at two different temperatures. The specific spectral fingerprints of different culture time points (48, 72, 96, and 120 h) were obtained. Of all strains, 88.5% (46/52) were discriminated as A. fumigatus, while the remaining 11.5% (6/52) produced results inconsistent with morphological analysis. Molecular sequencing, as a reference method for species identification, was used to validate the morphological analysis and matrix-assisted laser desorption/ionization time of flight MS. Chi-square tests (χ² test, P=0.05) demonstrated that the culture medium and incubation temperature had no effects on identification accuracy; however, identification accuracy of the strains in the 48-h group was lower than that in other groups. In addition, we found that ribosomal proteins extracted from A. fumigatus can be stored in different environments for at least 1 week, with their profiles remaining stable and strain identification results showing no change. This is beneficial for medical institutions with no mass spectrometer at hand. Overall, this study showed the powerful ability of VITEK MS V 3.0 in identifying A. fumigatus.

Blastoschizomyces capitatus pulmonary infections in immunocompetent patients: case report, case series and literature review

Blastoschizomyces capitatus is an uncommon opportunistic yeast associated with infections in neutropaenic patients secondary to haematological malignancies, with a special predilection for the lungs. Globalisation and population migration impact on the epidemiology of infection with this organism but its effect on the immunocompetent population has rarely been described. We present here a case report, an overview of 11 other cases published between 2000 and 2016, and a comprehensive literature review of Blastoschizomyces pneumonia in the non-immunocompromised. The median age at diagnosis was 68 years (range 40-86 years) and more than half the cases reported a positive history of either current or past tobacco smoking. Six cases had either clinical or radiological evidence of chronic obstructive pulmonary disease and three had a history of prior treated tuberculosis. Fluconazole and itraconazole, alone or in combination, was the most utilised treatment. We conclude that unlike most other invasive yeast species, B. capitatus poses an infectious risk for immunocompetent patients, usually of middle to older age with risk factors for distorted lung architecture. Further research is warranted into the pathophysiology of Blastoschizomyces infections in the immunocompetent, including standardised treatment options.

Use of 1,3-β-D-glucan in invasive fungal diseases in hematology patients

INTRODUCTION

Invasive fungal diseases (IFD) remain a leading cause of morbidity and mortality in hematology patients. Within a diagnostic-driven approach, the use of the serum (1,3)-ß-D-glucan (BDG) test represents a valid tool for the early diagnosis and treatment of IFD. Areas covered: The available literature on the use of BDG in hematology patients was systematically retrieved. Then, it was reviewed and discussed, to identify key issues pertaining to a clinically-oriented narrative presentation of the topic. Expert commentary: The use of BDG in hematology patients at risk for invasive aspergillosis (IA) is secondary to the use of galactomannan. However, since BDG is not specific for IA, it offers an advantage of diagnosing also other IFD, such as candidiasis and pneumocystosis. The limitations of BDG include high costs and lower sensitivity in hematology patients compared to other cohorts. The risk of false positive results is possibly lower in real life than in theory, since glucan-free equipment is available and modern dialysis membranes and blood products usually do not release BDG. Thus, in experienced hands and selected clinical situations, BDG is a useful diagnostic tool, particularly due to short turnover time to results and versatility in diagnosing different IFD.