Saprochaete capitata as an emerging fungus among patients with haematological malignencies

An unexpected opportunist: Magnusiomyces capitatus infection in an immunocompetent patient

Magnusiomyces capitatus is an uncommon opportunistic fungal pathogen primarily affecting immunocompromised individuals. While rare, cases have been reported in immunocompetent patients. We present a documented case of Magnusiomyces capitatus invasive infection in an immunocompetent patient with no previous medical history. This case shows that invasive fungal infections by Magnusiomyces capitatus might affect even the immunocompetent patients.

A case of Magnusiomyces capitatus isolated during monitoring in an antimicrobial diagnostic stewardship context

Magnusiomyces capitatus (M. capitatus) is an emerging opportunistic yeast in the Mediterranean region typically isolated from immunocompromised patients, usually affected by blood malignancies. We reported a rare case of M. capitatus infection, isolated from a drainage fluid in a patient affected by lung cancer recovered in the University Hospital of Campania "Luigi Vanvitelli", Naples, Italy. The isolate was identified by phenotypic methods, i.e., Gram and Lactophenol cotton blue (LCB) staining, and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis. We identified M. capitatus on the third day from Sabouraud Dextrose Agar supplemented with chloramphenicol and gentamicin. Antifungal susceptibility test revealed that 5-fluorocytosine was the most active drug against M. capitatus, followed by itraconazole and voriconazole, micafungin, amphotericin B and fluconazole, posaconazole, anidulafungin, and caspofungin. Our data showed the importance of an early cultural and fast microbiology diagnosis based on the characteristic morphologic features observed in Gram-stained smears of blood culture positive bottles, and the validation via MALDI-TOF MS. This dual approach has significant impact in the clinical management of infectious diseases and antibiotic stewardship, by integrating sample processing, fluid handling, and detection for rapid bacterial diagnosis.

Infection With Saprochaete Clavata in Children After Hematopoietic Cell Transplantation

Septic shock is a very rare manifestation of invasive fungal disease (IFD) in children after allogeneic hematopoietic cell transplantation (allo-HCT). The objective of this paper is analysis of two cases of pediatric patients with IFD caused by Saprochaete clavata after allo-HCT. Literature data on this infection in children and its outcome were also summarized. Infection with Saprochaete clavate presenting with symptoms of septic shock was being reported in 4 children, and 2 of them survived the infection. In conclusion, with quick diagnosis and quick treatment, the outcome of therapy of infection with Saprochaete clavata was successful.

A case of Saprochaete capitata pulmonary infection in a neutropenic HIV-infected patient

Introduction.

Saprochaete capitata is an emerging opportunistic fungus that is responsible for an uncommon mycosis known as geotrichosis, mainly reported in patients with haematological malignancies. It is a life-threatening condition associated with a high mortality rate of over 52 %. S. capitata may affect any organ, with a predilection for the lungs.

Case presentation.

Here we report a case of pulmonary geotrichosis in a neutropenic HIV-infected patient with a prior history of treated tuberculosis. The main risk factor for pulmonary geotrichosis is profound and prolonged neutropenia. To our knowledge, this is the first reported case of S. capitata infection occurring on top of probable active miliary tuberculosis.

Conclusion.

The clinical and radiological features are non-specific and similar to those of other pulmonary fungal diseases, hence the importance of mycological examination to confirm the diagnosis. Through this report, we urge clinicians to vigilantly consider S. capitata as an aetiological agent in the differential diagnosis of fungal infections in HIV-infected individuals and to routinely screen for associated infections.

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.

Critically ill patients with severe infections related to Geotrichum species: A French retrospective multicentre study

OBJECTIVES

Geotrichum spp can be responsible for severe infections in immunocompromised patients. We aim to describe Geotrichum-related infections in the ICU and to assess risk factors of mortality.

METHODS

Retrospective multicentre study, conducted in 14 French ICUs between 2002 and 2018, including critically ill adult patients with proven or probable infection related to Geotrichum species. Data were obtained from the medical charts.

RESULTS

Thirty-six patients, median age 60 years IQR [53; 66] were included. Most of the patients had haematological malignancies (78%). The reason for ICU admission was shock in half of the patients (n = 19, 53%) and respiratory failure in thirteen patients (36%). Median SOFA score was 8.5 IQR [7; 15]. Time between ICU admission and fungal diagnosis was 2.5 days [-1; 4]. Infection was disseminated in 27 (75%) patients with positive blood cultures in 25 patients (69%). Thirty patients (83%) received curative antifungal treatment in the ICU, in a median time of 1 day [0;1] after ICU admission. Twenty-four patients (67%) died in the ICU and hospital mortality rate was 69%. The number and extent of organ failures, as represented by SOFA score, were associated with mortality.

CONCLUSIONS

This study demonstrates poor outcome in critically ill patients with Geotrichum-related infections, which encourages a high level of suspicion.

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.

Management of Invasive Infections due to a Rare Arthroconidial Yeast, Saprochaete capitata, in Two Patients with Acute Hematological Malignancies

Saprochaete capitata is an arthroconidial yeast, found principally in the environment, even if it belongs also to the normal microbial flora that colonize human subjects. This yeast is increasingly associated with invasive infections in hematological patients, in particular in those affected by acute leukemia. An important risk factor that predisposes to this infection is the profound neutropenia present in such immunocompromised patients. Saprochaete spp. were found resistant to both echinocandins and fluconazole so the treatment is often difficult. Here, we report two cases of sepsis in two patients with acute leukemia. All of them had fatal events, due to the worsening of their clinical condition. An early diagnosis and appropriate management of these pathogens is important in consideration of the poor prognosis associated to these fungal invasive infections.

Epidemiological Characterization of Clinical Fungal Isolates from Pauls Stradinš Clinical University Hospital, Latvia: A 4-Year Surveillance Report

Nosocomial fungal infections are an emerging global public health threat that requires urgent attention and proper management. With the limited availability of treatment options, it has become necessary to understand the emerging epidemiological trends, mechanisms, and risk factors. However, very limited surveillance reports are available in the Latvian and broader European context. We therefore conducted a retrospective analysis of laboratory data (2017-2020) from Pauls Stradinš Clinical University Hospital (PSCUH), Riga, Latvia, which is one of the largest public multispecialty hospitals in Latvia. A total of 2278 fungal isolates were analyzed during the study period, with Candida spp. comprising 95% of the isolates, followed by Aspergillus spp. and Geotrichum spp. Amongst the Candida spp., C. albicans and C. glabrata made up about 75% of the isolates. The Department of Lung Diseases and Thoracic Surgery had the highest caseload followed by Intensive Care Department. Majority of the fungal isolates were collected from the bronchoalveolar lavage (37%), followed by urine (19%) and sputum (18%) samples. A total of 34 cases of candidemia were noted during the study period with C. albicans being the most common candidemia pathogen. Proper surveillance of emerging epidemiological trends serve as the most reliable and powerful cornerstone towards tackling this emerging threat.

All You Need To Know and More about the Diagnosis and Management of Rare Yeast Infections

Invasive infections with emerging yeasts such as Geotrichum, Saprochaete/Magnusiomyces, Trichosporon, and other species are associated with high morbidity and mortality rates. Due to the rarity and heterogeneity of these yeasts, medical mycology has lacked guidance in critical areas affecting patient management. Now, physicians and life scientists from multiple disciplines and all world regions have united their expertise to create the "Global guideline for the diagnosis and management of rare yeast infections: an initiative of the European Confederation of Medical Mycology in cooperation with the International Society for Human and Animal Mycology and the American Society for Microbiology." Recommendations are stratified for high- and low-resource settings and are therefore applicable worldwide. The advantages and disadvantages of various diagnostic methods and treatment options are outlined. This guideline reflects the current best-practice management for invasive rare yeast infections in a range of settings, with the intent of establishing a global standard of care for laboratorians and clinicians alike.

Identification and antifungal susceptibility of Saprochaete clavata from invasive infections in Turkey

Saprochaete clavata is an emerging opportunistic pathogen, that causes life-threatening infections, but there are limited evidence and information about the evaluation of in vitro antifungal susceptibility test results. The aim of this study was to determine S. clavata isolates from clinical specimens and to investigate their in vitro antifungal susceptibility. S. clavata was identified by API ID20C AUX (BioMérieux, Brussels, Belgium), MALDI TOF (Bruker Daltonik, Germany), and ITS gene region sequencing. In vitro susceptibility tests were performed using Sensititre YeastOne (TREK Diagnostic System, East Grinstead, UK). During the study period, 4,736 fungi were isolated from various clinical samples and, S. clavata was identified in eight patients with underlying diseases namely, pancreatic neoplasma, acute myeloid leukaemie, follicular lymphoma, cholelithiasis. Anidulafungin and micafungin minimum inhibitory concentration values were 1-2 and 1-4 mg/L, respectively, while those of the azole group antifungals were much lower. This is the first study in Turkey reporting isolation, identification and antifungal susceptibilities of S. clavata from clinical specimens. Higher MIC values seen in some isolates suggest that continuous monitoring of sensitivity rates and observation of regional differences will thus be useful guides in determining infection control and antifungal use policies.

Invasive Saprochaete Infections: An Emerging Threat to Immunocompromised Patients

Saprochaete clavata and Saprochaete capitata are emerging fungal pathogens that are responsible for life threatening infections in immunocompromised patients, particularly in the setting of profound neutropenia. They have been associated with multiple hospital outbreaks mainly in Europe. In this article, we present a comprehensive review of the epidemiology, clinical presentation, diagnosis, antifungal susceptibility and treatment of these organisms. The diagnosis of invasive Saprochaete disease is challenging and relies primarily on the isolation of the fungi from blood or tissue samples. Both species are frequently misidentified as they are identical macroscopically and microscopically. Internal transcribed spacer sequencing and matrix-assisted laser desorption ionization-time of flight mass spectrometry are useful tools for the differentiation of these fungi to a species level. Saprochaete spp. are intrinsically resistant to echinocandins and highly resistant to fluconazole. Current literature suggests the use of an amphotericin B formulation with or without flucytosine for the initial treatment of these infections. Treatment with extended spectrum azoles might be promising based on in vitro minimum inhibitory concentration values and results from case reports and case series. Source control and recovery of the immune system are crucial for successful therapy.

Stress Tolerance of Yeasts Dominating Reverse Osmosis Membranes for Whey Water Treatment

Filamentous yeast species belonging to the closely related Saprochaete clavata and Magnusiomyces spicifer were recently found to dominate biofilm communities on the retentate and permeate surface of Reverse Osmosis (RO) membranes used in a whey water treatment system after CIP (Cleaning-In-Place). Microscopy revealed that the two filamentous yeast species can cover extensive areas due to their large cell size and long hyphae formation. Representative strains from these species were here further characterized and displayed similar physiological and biochemical characteristics. Both strains tested were able to grow in twice RO-filtrated permeate water and metabolize the urea present. Little is known about the survival characteristics of these strains. Here, their tolerance toward heat (60, 70, and 80°C) and Ultraviolet light (UV-C) treatment at 255 nm using UV-LED was assessed as well as their ability to form biofilm and withstand cleaning associated stress. According to the heat tolerance experiments, the D60°C of S. clavata and M. spicifer is 16.37 min and 7.24 min, respectively, while a reduction of 3.5 to >4.5 log (CFU/mL) was ensured within 5 min at 70°C. UV-C light at a dose level 10 mJ/cm2 had little effect, while doses of 40 mJ/cm2 and upward ensured a ≥4log reduction in a static laboratory scale set-up. The biofilm forming potential of one filamentous yeast and one budding yeast, Sporopachydermia lactativora, both isolated from the same biofilm, was compared in assays employing flat-bottomed polystyrene microwells and peg lids, respectively. In these systems, employing both nutrient rich as well as nutrient poor media, only the filamentous yeast was able to create biofilm. However, on RO membrane coupons in static systems, both the budding yeast and a filamentous yeast were capable of forming single strain biofilms and when these coupons were exposed to different simulations of CIP treatments both the filamentous and budding yeast survived these. The dominance of these yeasts in some filter systems tested, their capacity to adhere and their tolerance toward relevant stresses as demonstrated here, suggest that these slow growing yeasts are well suited to initiate microbial biofouling on surfaces in low nutrient environments.

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.

Invasive Saprochaete capitata Infection in a Patient with Autosomal Recessive CARD9 Deficiency and a Review of the Literature

PURPOSE

Autosomal recessive (AR) CARD9 deficiency is an inherited immune disorder which results in impaired innate immunity against various fungi. Superficial and invasive fungal infections, mainly caused by Candida or Trichophyton species, are the hallmark of CARD9 deficiency. Together with the increasing number of CARD9-deficient patients reported, different pathogenic fungal species have been described such as Phialophora, Exophiala, Corynespora, Aureobasidium, and Ochroconis. Saprochaete capitata is an opportunistic infectious agent in immunocompromised patients and is a common cause of invasive fungal disease in patients with hematological malignancies. In this study, we investigated the causative genetic defect in a patient with S. capitata fungal infection which disseminated to lymph nodes and common bile duct.

METHODS

The identification of the isolated yeast strain was made by direct microscopic examination and confirmed by internal transcribed spacer (ITS) sequencing. We applied whole exome sequencing to search for the disease-causing mutation. Sanger sequencing was used to validate the mutation in the patient and his parents.

RESULTS

S. capitata was isolated from the biopsy specimen as the causative microorganism responsible for the invasive fungal disease in the patient. Whole exome sequencing revealed a homozygous c.883C > T, (p.Q295*) mutation in CARD9, confirmed by Sanger sequencing.

CONCLUSIONS

This is the first report of invasive Saprochaete infection associated with autosomal recessive (AR) CARD9 deficiency in the literature and thereby further extends the spectrum of fungal diseases seen in these patients.

Genome sequence of the opportunistic human pathogen Magnusiomyces capitatus

The yeast Magnusiomyces capitatus is an opportunistic human pathogen causing rare yet severe infections, especially in patients with hematological malignancies. Here, we report the 20.2 megabase genome sequence of an environmental strain of this species as well as the genome sequences of eight additional isolates from human and animal sources providing an insight into intraspecies variation. The distribution of single-nucleotide variants is indicative of genetic recombination events, supporting evidence for sexual reproduction in this heterothallic yeast. Using RNAseq-aided annotation, we identified genes for 6518 proteins including several expanded families such as kexin proteases and Hsp70 molecular chaperones. Several of these families are potentially associated with the ability of M. capitatus to infect and colonize humans. For the purpose of comparative analysis, we also determined the genome sequence of a closely related yeast, Magnusiomyces ingens. The genome sequences of M. capitatus and M. ingens exhibit many distinct features and represent a basis for further comparative and functional studies.

Saprochaete capitata (Geotrichum capitatum), an emerging fungal infection in kidney transplant recipients

We are reporting the case of an 82-year-old Yemeni patient, renal transplant recipient who was admitted to our institution and who subsequently developed disseminated infection with Saprochaete capitata. This pathogenic fungus is rarely reported in patients with solid organ trans-plants. Saprochaete capitata is an emerging fungal pathogen, ubiquitously spread in the environment. This is the second case to our knowledge of infection with Saprochaete capitata in a renal transplant patient. Our patient was treated for multiple nosocomial infections with prolonged antibiotic courses. He succumbed to the infection with Saprochaete capitate after several weeks spent in the intensive care unit.

Isolation of the Rare Opportunistic Yeast Saprochaete capitata from Clinical Samples-Experience from a Tertiary Care Hospital in Southern India and a Brief Review of the Literature

Introduction

Saprochaete capitata (Teleomorph: Magnusiomyces capitatus) is a ubiquitous yeast found in environmental sources such as soil, water, air, plants and dairy products. It is also a part of the normal microbial flora in humans. The yeast is being increasingly reported as an opportunistic pathogen, especially in patients in the haemato-oncology setting, the infection being often mistakenly diagnosed as invasive candidiasis.

Aim

To review the epidemiological, clinical and microbiological features of six patients admitted in our hospital over a period of 10 years (from January 2007 to December 2016), from whom Saprochaete capitata was isolated.

Materials and Methods

A retrospective study was conducted and the epidemiological, clinical, imaging and microbiological data of the six patients were collected and analysed.

Results

The age of the six patients ranged from 19 years to 65 years with a median age of 53 years. There were two males and four females. In three out of the six patients, the isolation of S. capitata was considered clinically significant as the yeast was isolated repeatedly from blood and/or respiratory specimens and the clinical features could not be explained by any other alternative diagnosis. Haematological malignancy was the underlying disease in three out of the six patients while one patient was on triple immunosuppression following renal transplantation four years back. Three out of the six patients had severe neutropenia with Absolute Neutrophil Count (ANC) ≤ 500 at the time of isolation of S. capitata. Two patients with clinical features of fungal sepsis received antifungal therapy with Amphotericin B but succumbed within a short period of starting the therapy. The post renal transplant patient who presented with pneumonia recovered after treatment with a combination of Amphotericin B and Voriconazole.

Conclusion

Awareness regarding the epidemiological, clinical and microbiological aspects of invasive infections caused by S. capitata is essential for early recognition and appropriate management.