Clinical significance of filamentous basidiomycetes illustrated by isolates of the novel opportunist Ceriporia lacerata from the human respiratory tract

Fusarium spp. causing invasive disease in humans: A case series from north India

Owing to their inherent resistance to different classes of antifungals, early identification of Fusarium spp. is crucial. In this study, 10 clinical isolates were included from patients with invasive fusariosis involving lungs, sinuses, or both. Clinico-radiological data were collected. Samples were processed by standard laboratory procedures. Three gene regions (ITS, TEF1, and RPB2) were amplified by PCR for multilocus sequencing. Fusarium MLST, FUSARIUM-ID, and FUSARIOID-ID databases were used for final identification. Antifungal susceptibility testing was performed by broth microdilution following CLSI M38-A3 and Sensititre™ YeastOne™ YO9 plate. Pulmonary involvement was seen in all patients, and sino-nasal involvement was present in six. Radiologically, consolidations and cavitations were present in eight and six cases, respectively. Halo sign was present in six; reverse halo sign was also found in three of them. Direct microscopy showed septate hyphae that were morphologically different from those found in aspergillosis. Results of the molecular identification were as follows: two Fusarium irregulare, one Fusarium pernambucanum, one Fusarium incarnatum, one Fusarium sp. FIESC 30, two Fusarium keratoplasticum, one Fusarium falciforme, one Fusarium pseudonygamai, and one Fusarium delphinoides. For both Fusarium solani (FSSC) and Fusarium incarnatum-equiseti (FIESC) species complexes, amphotericin B had the lowest minimum inhibitory concentrations (MICs). Importantly, for terbinafine, all FIESC isolates had low MICs, while FSSC isolates had high MICs. In some cases, early identification of Fusarium spp. is possible by means of morphology of hyphae on direct microscopy and findings on radiology. Molecular identification, at least to the species complex level, is crucial for the choice of antifungals.

Microbiome and Mycobiome Analyses of Continuous Positive Airway Pressure Devices

OBJECTIVES

Microorganisms are likely present in continuous positive airway pressure (CPAP) devices in daily use. Given the potential risk of infection among CPAP users, we aimed to compare the microbiomes of CPAP devices with those of nasal mucosa samples obtained from patients using these devices.

METHODS

We conducted a prospective cohort study at multiple tertiary medical institutions. Samples were collected from the tubes and filters of CPAP devices and the nasal mucosa of device users. Microbiomes and mycobiomes were analyzed using 16S ribosomal RNA and internal transcribed spacer region sequencing. The results were compared according to sampling site and usage duration for each patient.

RESULTS

Overall, 27 paired samples of human nasal mucosa and CPAP components were analyzed. Bacteria were detected in 7 of the 27 tubes (25.9%) and in 22 of the 27 filters (81.5%). Fungi were found in 2 tubes (7.4%) and 16 filters (59.3%). The most prevalent bacterial phyla across all samples were Actinobacteria and Firmicutes. Fungi were not detected in any nasal mucosa samples. However, fungi were identified in the CPAP filters and tubes, with the Basidiomycota and Ascomycota phyla predominating. No significant associations were identified according to sampling site or duration of CPAP use.

CONCLUSION

Some bacteria or fungi are detectable in CPAP samples, even after a short period of CPAP usage. However, the association between respiratory infections and these microbiomes or mycobiomes was not investigated. Further research is required to clarify the risk posed by CPAP devices as a microbial contamination source.

The first suspected disseminated Hormographiella aspergillata infection in China, diagnosed using metagenomic next-generation sequencing: a case report and literature review

Hormographiella aspergillata is a rare and emerging cause of invasive mould infections in patients with haematological malignancies, with a mortality rate of approximately 70%. Here, we present the first reported case of suspected disseminated H. aspergillata infection in China. The patient experienced a second relapse of acute myeloid leukaemia and developed neutropenia, fever, discrepant blood pressure between limbs, and cutaneous lesions limited to the left upper extremity. Since lung tissue biopsy was not feasible, metagenomic next-generation sequencing (mNGS) and panfungal polymerase chain reaction (PCR) analysis of bronchoalveolar lavage fluid and blood samples were performed, which indicated probable H. aspergillata pulmonary infection. Histopathology of cutaneous lesions revealed numerous fungal hyphae within dermal blood vessels. mNGS of a skin biopsy sample identified H. aspergillata sequences, and the fungi was subsequently recovered from fungal culture, proving cutaneous H. aspergillata infection. Despite combined antifungal therapy, the patient died owing to disease progression. Additionally, 22 previously reported cases of invasive H. aspergillata infection were reviewed in patients with haematological malignancies. Thus, mNGS is a powerful diagnostic tool for the early and effective detection of invasive H. aspergillata infections, with the advantage of sequencing all potential pathogens, and providing results within 24 h.

Subcutaneous mycosis caused by filamentous basidiomycete Megasporoporia setulosa-first report of human infection

Filamentous basidiomycetes are an emerging cause of human infection in tropical and subtropical regions. We report a case of subcutaneous infection caused by the shelf fungus, Megasporoporia setulosa, in an immunocompetent male. This is also the first report of human infection caused by this filamentous basidiomycete. Identification of the fungus could only be achieved by sequencing the ITS and LSU regions of rDNA. The patient recovered following surgery and treatment with amphotericin B and oral itraconazole. This report underscores the cross-kingdom pathogenicity of plant fungi and the importance of molecular tools for definitive identification of nonsporulating fungal species.

The Fungal and Bacterial Interface in the Respiratory Mycobiome with a Focus on Aspergillus spp

The heterogeneity of the lung microbiome and its alteration are prevalently seen among chronic lung diseases patients. However, studies to date have primarily focused on the bacterial microbiome in the lung rather than fungal composition, which might play an essential role in the mechanisms of several chronic lung diseases. It is now well established that Aspergillus spp. colonies may induce various unfavorable inflammatory responses. Furthermore, bacterial microbiomes such as Pseudomonas aeruginosa provide several mechanisms that inhibit or stimulate Aspergillus spp. life cycles. In this review, we highlighted fungal and bacterial microbiome interactions in the respiratory tract, with a focus on Aspergillus spp.

Assessment of a novel continuous cleaning device using metatranscriptomics in diverse hospital environments

Introduction

Despite routine implementation of cleaning and disinfection practices in clinical healthcare settings, high-touch environmental surfaces and contaminated equipment often serve as reservoirs for the transmission of pathogens associated with healthcare-associated infections (HAIs).

Methods

The current study involved the analysis of high-touch surface swabs using a metatranscriptomic sequencing workflow (CSI-Dx™) to assess the efficacy of cleanSURFACES® technology in decreasing microbial burden by limiting re-contamination. This is a non-human single center study conducted in the Emergency Department (ED) and on an inpatient Oncology Ward of Walter Reed National Military Medical Center that have followed hygienic practices during the COVID-19 pandemic environment.

Results

Although there was no difference in observed microbial richness (two-tailed Wilcoxon test with Holm correction, P > 0.05), beta diversity findings identified shifts in microbial community structure between surfaces from baseline and post-intervention timepoints (Day 1, Day 7, Day 14, and Day 28). Biomarker and regression analyses identified significant reductions in annotated transcripts for various clinically relevant microorganisms' post-intervention, coagulase-negative staphylococci and Malassezia restricta, at ED and Oncology ward, respectively. Additionally, post-intervention samples predominantly consisted of Proteobacteria and to a lesser extent skin commensals and endogenous environmental microorganisms in both departments.

Discussion

Findings support the value of cleanSURFACES®, when coupled with routine disinfection practices, to effectively impact on the composition of active microbial communities found on high-touch surfaces in two different patient care areas of the hospital (one outpatient and one inpatient) with unique demands and patient-centered practices.

Dietary supplementation with Ceriporia lacerata improves learning and memory in a scopolamine-induced amnesia mouse model

Ceriporia lacerata (CL) is a species of white rot fungi. In this study, we have examined the beneficial effect of CL on scopolamine-induced memory impairment in mice. A freeze-dried CL mycelial culture broth was dissolved and orally administered to scopolamine-treated C57BL/6J mice followed by behavioral tests using the Y-maze, passive avoidance, and Morris water maze tasks. CL administration at a daily dose of 200 mg/kg body weight resulted in restoration of exploration reduction and improvement of associative and spatial learning and memory impairment in scopolamine-treated mice. Concomitantly, heme oxygenase-1 was highly expressed in the hippocampal region of CL-administered mice. Moreover, the ethanolic extract of CL significantly increased the transcriptional activity of antioxidant response element and attenuated the glutamate-induced cytotoxicity in HT22 mouse hippocampal neuronal cells. These findings suggest that the CL intake can confer a beneficial effect on learning and memory presumably through protecting hippocampal neuronal cells from oxidative stress-induced damage.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10068-021-00945-5.

Clinical and etiological analysis of co-infections and secondary infections in COVID-19 patients: An observational study

Background

Co‐infections, secondary bacterial or fungal infections, are important risk factors for poor outcomes in viral infections. The prevalence of co‐infection and secondary infection in patients infected with SARS‐CoV‐2 is not well understood.

Aims

To investigate the role of co‐infections and secondary infections in disease severity of hospitalized individuals with COVID‐19.

Materials and Methods

A retrospective study was carried out between 11 January 2020 and 1 March 2020 among 408 laboratory confirmed COVID‐19 patients in China. These patients were divided into three groups based on disease severity: mild or moderate, severe, or critically ill. Microbiological pathogens in blood, urine, and respiratory tract specimens were detected by the combination of culture, serology, polymerase chain reaction, and metagenomic next‐generation sequencing (mNGS).

Results

The median age of participants was 48 years (IQR 34–60 years). Fifty‐two patients (12.7%) had at least one additional pathogen, 8.1% were co‐infected, and 5.1% had a secondary infection. There were 13 Mycoplasma pneumoniae cases, 8 Haemophilus influenzae cases, 8 respiratory viruses, and 3 Streptococcus pneumoniae cases, primarily detected in mild and moderate COVID‐19 patients. Hospital‐acquired infection pathogens were more common in critically ill patients. Compared to those without additional pathogens, patients with co‐infections and/or secondary infections were more likely to receive antibiotics (p < 0.001) and have elevated levels of d‐dimer (p = 0.0012), interleukin‐6 (p = 0.0027), and procalcitonin (p = 0.0002). The performance of conventional culture was comparable with that of mNGS in diagnosis of secondary infections.

Conclusion

Co‐infections and secondary infections existed in hospitalized COVID‐19 patients and were relevant to the disease severity. Screening of common respiratory pathogens and hospital infection control should be strengthened.

Gloeostereum cimri, a novel shelf fungus isolated from a human pulmonary cyst

Filamentous basidiomycetes are uncommon agents of human diseases, despite their ubiquitous presence in the environment. We present a case of symptomatic pulmonary infection in a 38-year-old male with cough and fever; a thin-walled cyst in the posterior left upper pulmonary lobe was revealed by radiography. A non-sporulating fungus was isolated from sputum and biopsy material from the cyst. ITS and LSU sequences placed the fungus phylogenetically in Agaricales, family Cyphellaceae, and identified it as a member of shelf fungi in Gloeostereum, but without identity to any known species. The new species is described as Gloeostereum cimri. The clinical strain showed high MIC to voriconazole (>8 µg/ml) but had low MIC to amphotericin B (0.5 µg/ml).

Hormographiella aspergillata: an emerging basidiomycete in the clinical setting? A case report and literature review

Background

Filamentous basidiomycetes are mainly considered to be respiratory tract colonizers but the clinical significance of their isolation in a specimen is debatable. Hormographiella aspergillata was first reported as a human pathogen in 1971. We discuss the role of this mold as a pathogen or colonizer and give an update on diagnostic tools and in vitro antifungal susceptibility.

Case presentation

We identified three cases of H. aspergillata with respiratory symptoms in a short period of time. One invasive infection and two colonizations were diagnosed. Culture supernatants showed that H. aspergillata can produce galactomannan and β-D-glucan but not glucuronoxylomannan. For the first time, isavuconazole susceptibility was determined and high minimum inhibitory concentrations (MICs) were found. Liposomal amphotericin B and voriconazole have the lowest MICs.

Conclusion

To date, 22 invasive infections involving H. aspergillata have been reported. On isolation of H. aspergillata, its pathogenic potential in clinical settings can be tricky. Molecular identification and antifungal susceptibility testing are essential considering high resistance against several antifungal therapies.

Clinical impact of molecular identification of rare yeasts and nonsporulating molds recovered in culture from clinical specimens

Uncommon fungi can cause opportunistic infections and are often unidentifiable using phenotypic methods. Molecular techniques, like DNA sequencing, may permit species-level identification but results may be challenging to interpret. To determine the clinical impact of molecular identification in this setting, we performed a retrospective review of fungal isolates referred for molecular identification. Seventy-five distinct fungal species were identified from 93 referred isolates, 31 (41%) of which are not known to be human pathogens. DNA sequencing prompted change in anti-infective therapy in only 3 (3.5%) cases but significantly delayed culture turnaround time (40 ± 31 vs. 30 ± 13 days, P < 0.001). Patient immune status and concurrent histologic or serologic testing significantly correlated with the proportion of pathogenic isolates recovered and patients treated (χ², P < 0.05). Molecular identification of uncommon fungal isolates should be limited to specialized clinical settings such as patients with immunosuppression and/or concurrent positive histology or fungal serology.

Role of the lung microbiome in HIV pathogenesis

PURPOSE OF REVIEW

The purpose of this review is to summarize recent findings on the lung microbiome in HIV-infected patients and associated pulmonary diseases, and the relationship of airway microbial communities to metabolic and immune signatures within this patient population.

RECENT FINDINGS

The lung microbiome in HIV infection is a relatively new and rapidly developing field; early studies in the field produced inconclusive evidence as to whether HIV-infection changes the lower airway microbiome. More recent microbiome investigations have addressed these inconsistencies by incorporating systems biology approaches and laboratory models. Several investigations have now identified enrichment of Prevotella, Veillonella, and Streptococcus in the lower airways as consistent correlates of advanced HIV-infection and HIV-associated pulmonary diseases. These bacteria are associated with specific metabolic and immune profiles within the lung and circulation, providing the first indication that the lung microbiome may play a functional role in the pathogenesis of HIV-infection and HIV-associated pulmonary disease.

SUMMARY

This review summarizes knowledge to date on the lung microbiome in HIV infection, as well as challenges and accomplishments in the field within the last 2 years. Although the lung microbiome in HIV infection is still an emerging field, recent studies have formed a framework for future functional analysis of microbes in HIV pathogenesis.

Are we ready for the global emergence of multidrug-resistant Candida auris in Taiwan?

Candida auris is a recently identified multi-resistant Candida species, first reported in Japan in 2009, and poses a serious global health threat. Lack of awareness of this new Candida species and difficulties with laboratory identification have impacted significantly on outbreak detection and management, and compromised patient outcome. Accordingly, there is an urgent need to raise awareness of healthcare personnel to this emerging pathogen and determine its prevalence, impact, and challenges to the Taiwan healthcare system. Enhanced laboratory testing strategies are needed to differentiate C. auris from other Candida species to provide accurate diagnosis and implement control measures early enough to prevent hospital outbreaks. In this report, we review the key epidemiological, microbiological and clinical characteristics of C. auris and provide the results of a multicenter surveillance study of C. auris in Taiwan. We also conducted a web-based survey to determine awareness of the medical community to C. auris and the capability of Taiwanese hospital laboratories to identify this microorganism. C. auris has not yet been isolated from humans in Taiwan, but the unique features of this microorganism and its ability to reach across international boundaries justify the importance of these initiatives in Taiwan.

Cutaneous Emboli of Invasive Basidiomycosis in a Child With Aplastic Anemia

Invasive fungal diseases are a significant cause of mortality among the immunocompromised. This report documents an unusual case of disseminated fungal infection in a child with severe aplastic anemia. The offending fungus, a Basidiomycete, is rarely known to cause human infections. The patient presented acutely with multiple purpuric skin lesions in various parts of the body. The skin biopsy revealed septated fungal hyphae embolized within small dermal blood vessels. Molecular sequencing indicated Earliella scabrosa as the likely organism. The clinical course of the infection was inexorable despite systemic antifungal treatment, resulting in mortality. The literature of human infections due to Basidiomycetes, the usefulness of histopathology in the early diagnosis of the infection, and possible treatment options are discussed.

Topographic diversity of the respiratory tract mycobiome and alteration in HIV and lung disease

RATIONALE

Microbiome studies typically focus on bacteria, but fungal species are common in many body sites and can have profound effects on the host. Wide gaps exist in the understanding of the fungal microbiome (mycobiome) and its relationship to lung disease.

OBJECTIVES

To characterize the mycobiome at different respiratory tract levels in persons with and without HIV infection and in HIV-infected individuals with chronic obstructive pulmonary disease (COPD).

METHODS

Oral washes (OW), induced sputa (IS), and bronchoalveolar lavages (BAL) were collected from 56 participants. We performed 18S and internal transcribed spacer sequencing and used the neutral model to identify fungal species that are likely residents of the lung. We used ubiquity-ubiquity plots, random forest, logistic regression, and metastats to compare fungal communities by HIV status and presence of COPD.

MEASUREMENTS AND MAIN RESULTS

Mycobiomes of OW, IS, and BAL shared common organisms, but each also had distinct members. Candida was dominant in OW and IS, but BAL had 39 fungal species that were disproportionately more abundant than in the OW. Fungal communities in BAL differed significantly by HIV status and by COPD, with Pneumocystis jirovecii significantly overrepresented in both groups. Other fungal species were also identified as differing in HIV and COPD.

CONCLUSIONS

This study systematically examined the respiratory tract mycobiome in a relatively large group. By identifying Pneumocystis and other fungal species as overrepresented in the lung in HIV and in COPD, it is the first to determine alterations in fungal communities associated with lung dysfunction and/or HIV, highlighting the clinical relevance of these findings. Clinical trial registered with www.clinicaltrials.gov (NCT00870857).

Prevalence and mechanism of triazole resistance in Aspergillus fumigatus in a referral chest hospital in Delhi, India and an update of the situation in Asia

Aspergillus fumigatus causes varied clinical syndromes ranging from colonization to deep infections. The mainstay of therapy of Aspergillus diseases is triazoles but several studies globally highlighted variable prevalence of triazole resistance, which hampers the management of aspergillosis. We studied the prevalence of resistance in clinical A. fumigatus isolates during 4 years in a referral Chest Hospital in Delhi, India and reviewed the scenario in Asia and the Middle East. Aspergillus species (n = 2117) were screened with selective plates for azole resistance. The isolates included 45.4% A. flavus, followed by 32.4% A. fumigatus, 15.6% Aspergillus species and 6.6% A. terreus. Azole resistance was found in only 12 (1.7%) A. fumigatus isolates. These triazole resistant A. fumigatus (TRAF) isolates were subjected to (a) calmodulin and β tubulin gene sequencing (b) in vitro antifungal susceptibility testing against triazoles using CLSI M38-A2 (c) sequencing of cyp51A gene and real-time PCR assay for detection of mutations and (d) microsatellite typing of the resistant isolates. TRAF harbored TR₃₄/L98H mutation in 10 (83.3%) isolates with a pan-azole resistant phenotype. Among the remaining two TRAF isolates, one had G54E and the other had three non-synonymous point mutations. The majority of patients were diagnosed as invasive aspergillosis followed by allergic bronchopulmonary aspergillosis and chronic pulmonary aspergillosis. The Indian TR₃₄/L98H isolates had a unique genotype and were distinct from the Chinese, Middle East, and European TR₃₄/L98H strains. This resistance mechanism has been linked to the use of fungicide azoles in agricultural practices in Europe as it has been mainly reported from azole naïve patients. Reports published from Asia demonstrate the same environmental resistance mechanism in A. fumigatus isolates from two highly populated countries in Asia, i.e., China and India and also from the neighboring Middle East.

Equilibrium and kinetic studies of copper biosorption by dead Ceriporia lacerata biomass isolated from the litter of an invasive plant in China

BACKGROUND

Ceriporia lacerata, a strain of white-rot fungus isolated from the litter of an invasive plant (Solidago canadensis) in China, was little known about its properties and utilization. In this work, the copper(II) biosorption characteristics of formaldehyde inactivated C. lacerata biomass were examined as a function of initial pH, initial copper(II) concentration and contact time, and the adsorptive equilibrium and kinetics were simulated, too.

RESULTS

The optimum pH was found to be 6.0 at experimental conditions of initial copper(II) concentration 100 mg/L, biomass dose 2 g/L, contact time 12 h, shaking rate 150 r/min and temperature 25°C. Biosorption equilibrium cost about 1 hour at experimental conditions of pH 6.0, initial copper(II) concentration 100 mg/L, C. lacerata dose 2 g/L, shaking rate 150 r/min and temperature 25°C. At optimum pH 6.0, highest copper(II) biosorption amounts were 6.79 and 7.76 mg/g for initial copper(II) concentration of 100 and 200 mg/L, respectively (with other experimental parameters of C. lacerata dose 2 g/L, shaking rate 150 r/min and temperature 25°C). The pseudo second-order adsorptive model gave the best adjustment for copper(II) biosorption kinetics. The equilibrium data fitted very well to both Langmuir and Freundlich adsorptive isotherm models.

CONCLUSIONS

Without further acid or alkali treatment for improving adsorption properties, formaldehyde inactivated C. lacerata biomass possesses good biosorption characteristics on copper(II) removal from aqueous solutions.

Molecular epidemiology and in-vitro antifungal susceptibility of Aspergillus terreus species complex isolates in Delhi, India: evidence of genetic diversity by amplified fragment length polymorphism and microsatellite typing

Aspergillus terreus is emerging as an etiologic agent of invasive aspergillosis in immunocompromised individuals in several medical centers in the world. Infections due to A. terreus are of concern due to its resistance to amphotericin B, in vivo and in vitro, resulting in poor response to antifungal therapy and high mortality. Herein we examined a large collection of molecularly characterized, geographically diverse A. terreus isolates (n = 140) from clinical and environmental sources in India for the occurrence of cryptic A. terreus species. The population structure of the Indian A. terreus isolates and their association with those outside India was determined using microsatellite based typing (STR) technique and Amplified Fragment Length Polymorphism analysis (AFLP). Additionally, in vitro antifungal susceptibility of A. terreus isolates was determined against 7 antifungals. Sequence analyses of the calmodulin locus identified the recently described cryptic species A. hortai, comprising 1.4% of Aspergillus section Terrei isolates cultured from cases of aspergilloma and probable invasive aspergillosis not reported previously. All the nine markers used for STR typing of A. terreus species complex proved to be highly polymorphic. The presence of high genetic diversity revealing 75 distinct genotypes among 101 Indian A. terreus isolates was similar to the marked heterogeneity noticed in the 47 global A. terreus population exhibiting 38 unique genotypes mainly among isolates from North America and Europe. Also, AFLP analysis showed distinct banding patterns for genotypically diverse A. terreus isolates. Furthermore, no correlation between a particular genotype and amphotericin B susceptibility was observed. Overall, 8% of the A. terreus isolates exhibited low MICs of amphotericin B. All the echinocandins and azoles (voriconazole, posaconazole and isavuconazole) demonstrated high potency against all the isolates. The study emphasizes the need of molecular characterization of A. terreus species complex isolates to better understand the ecology, acquisition and transmission of this species.

Triazole-resistant Aspergillus fumigatus harbouring G54 mutation: Is it de novo or environmentally acquired?

Triazole resistance in Aspergillus fumigatus develops in patients with chronic lung diseases receiving long-term azole therapy or by environmental selection of resistant A. fumigatus. Here we report for the first time the isolation of triazole-resistant A. fumigatus (TRAF) harbouring the G54E mutation from environmental samples in India, Romania and Tanzania. This mutation in the cyp51A azole target gene of A. fumigatus is so far considered as de novo occurring in patients due to prolonged exposure to azoles. A total of 81 soil and woody debris samples from India, Romania and Tanzania were processed for detection of TRAF and determination of their susceptibility to medical triazoles and fungicides. cyp51A sequencing and real-time PCR were performed for detection of mutations. The isolates were genotyped by microsatellite typing. Overall, 25% of samples (20/81) from India, Romania and Tanzania harboured TRAF. Of the 20 samples harbouring TRAF, a single resistance mechanism, the G54E mutation, was found in 16 samples from three countries. This mechanism was responsible for 46.4% of resistant isolates from Tanzania, 30.4% from Romania and 20.0% from India. The G54E isolates revealed high MICs of itraconazole and posaconazole and were cross-resistant to agricultural fungicides. The majority of the Romanian and Tanzanian G54E isolates had an identical genotype. The present report describes the genetic heterogeneity of TRAF strains harbouring the G54E mutation in the environment of India, Romania and Tanzania. It may be anticipated that long-term exposure of A. fumigatus to fungicides may induce selection of G54 mutants in the environment.

Recognizing filamentous basidiomycetes as agents of human disease: A review

Filamentous basidiomycetes (BM) are common environmental fungi that have recently emerged as important human pathogens, inciting a wide array of clinical manifestations that include allergic and invasive diseases. We reviewed 218 reported global cases of BM fungi. The most common etiologic agent was Schizophyllum commune in 52.3% (114/218) of the cases followed by Hormographiella aspergillata (n = 13; 5.9%), Ceriporia lacerata (n = 11; 5%), and, rarely, Volvariella volvacea, Inonotus tropicalis, Irpex lacteus, Phellinus undulates, Perenniporia species, Bjerkandera adusta, Sporotrichum pruinosum, Phanerochaete steroids, and Cyclomyces tabacinus. These fungi are present in the environment as gilled mushrooms, shelf fungi, and bracket fungi. However, in clinical settings, they usually present as nonsporulating white moulds that are difficult to identify. Moreover, the GenBank database of these fungi is limited. Regarding the country-wise distribution of cases, Japan topped the list with about 43% (n = 94) of globally reported cases, followed by India (57; 26%), the United States (4%), Austria (3.2%), Iran (3.2%), France (2.8%), and the remaining one-third from 16 other countries. The respiratory tract was the most commonly afflicted site (n = 71), with the majority of the cases (42; 59.1%) being allergic in etiology and comprising 34 cases of allergic bronchopulmonary mycosis. Also, B. adusta has been implicated in a recently described clinical entity, that is, fungus associated chronic cough, reported exclusively from Japan. BM fungi-incited diseases are currently underdiagnosed due to lack of awareness and expertise, warranting comprehensive epidemiological and susceptibility studies to determine their prevalence and to predict a more appropriate therapy.

Possible Tyromyces fissilis (Basidiomycota, Polyporales) co-infection in a lung transplant recipient

Invasive fungal diseases are severe complication of the lung transplant patients' follow-up as they are increasing the risk of rejection. We report a patient who developed possible Tyromyces fissilis co-infection during graft rejection episode 2 years after bilateral lung transplantation for cystic fibrosis. The fungus was detected using conventional culture methods as a filamentous basidiomycete and further placed to T. fissilis species based on internal transcribed spacer (ITS) rDNA sequences. The patient was treated according to the susceptibility testing results by voriconazole in combination with the anti-rejection therapy and recovered completely within few weeks. This is, to our knowledge, the first published case report of T. fissilis as a possible causative agent of an infection/rejection episode in a lung transplant recipient.

A case of invasive pulmonary infection caused by novel species of Perenniporia

Perenniporia species, members of basidiomycetes, are known as decay fungi from wood of hardwood tree species. The clinical significance of these non-sporulating fungi from respiratory tract specimens is unknown. They have frequently been discarded as contaminants. There was only one case report of pulmonary fungal ball with positive culture for a Perenniporia species. We report herein a case of invasive pulmonary infection caused by the novel species of Perenniporia in a 44-year-old woman with active systemic lupus erythematosus who was successfully treated with voriconazole.

New clonal strain of Candida auris, Delhi, India

A new clonal strain of Candida auris is an emerging etiologic agent of fungemia in Delhi, India. In 12 patients in 2 hospitals, it was resistant to fluconazole and genotypically distinct from isolates from South Korea and Japan, as revealed by M13 and amplified fragment length polymorphism typing.

Multidrug-resistant endemic clonal strain of Candida auris in India

Candida auris is a recently described rare agent of fungemia. It is notable for its antifungal resistance. A total of 15 C. auris isolates, originating from seven cases of fungemia, three cases of diabetic gangrenous foot, and one case of bronchopneumonia from a tertiary care hospital in south India, were investigated. All of the 15 isolates were identified by sequencing and 14 of these along with 12 C. auris isolates previously reported from two hospitals in Delhi, north India, two each from Japan and Korea were genotyped by amplified fragment length polymorphism (AFLP). In vitro antifungal susceptibility testing (AFST) was done by the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method. Candida auris isolates were misidentified as Candida haemulonii by VITEK. All were resistant to fluconazole [geometric mean minimum inhibitory concentration (MIC) 64 μg/ml] and 11 isolates were resistant to voriconazole (MIC ≥1 μg/ml). Forty-seven percent of the C. auris isolates were resistant to flucytosine (MIC ≥64 μg/ml) and 40% had high MIC (≥1 μg/ml) of caspofungin. Breakthrough fungemia developed in 28.6% of patients and therapeutic failure in 4 (66.7%) patients. Interestingly, the 26 Indian C. auris isolates from north and south India were clonal and phenotypically and genotypically distinct from Korean and Japanese isolates. The present study demonstrates that C. auris is a potential emerging pathogen that can cause a wide spectrum of human mycotic infections. The prevalence of a C. auris endemic clonal strain resistant to azoles and other antifungals in Indian hospitals with high rates of therapeutic failure in cases of fungemia is worrisome.

A case of allergic fungal rhinosinusitis due to Ceratocystis adiposa

Ceratocystis adiposa known as phytopathogen of conifers has not been recognized so far as a human pathogen. Herein, we report for the first time a case of allergic fungal rhinosinusitis due to C. adiposa. The fungus was identified by sequencing internal transcribed spacer of rDNA and D1/D2 of larger subunit region.

Clinical significance and molecular characterization of nonsporulating molds isolated from the respiratory tracts of bronchopulmonary mycosis patients with special reference to basidiomycetes

Nonsporulating molds (NSMs), especially basidiomycetes, have predominantly been reported as human pathogens responsible for allergic and invasive disease. Their conventional identification is problematic, as many isolates remain sterile in culture. Thus, inconclusive culture reports might adversely affect treatment decisions. The clinical significance of NSMs in pulmonary mycoses is poorly understood. We sequenced the internal transcribed spacer (ITS) region and D1/D2 domain of the larger subunit (LSU) of 52 NSMs isolated from respiratory specimens. The basidiomycetes were the predominant NSMs, of which Schizophyllum commune was the most common agent in allergic bronchopulmonary mycosis (ABPM), followed by Ceriporia lacerata in invasive fungal disease. Porostereum spadiceum, Phanaerochaete stereoides, Neosartorya fischeri, and Marasmiellus palmivorus were the other molds observed. Application of ITS and LSU region sequencing identified 92% of the isolates. The antifungal susceptibility data revealed that all basidiomycetes tested were susceptible to amphotericin B and resistant to caspofungin, fluconazole, and flucytosine. Except for 3 isolates of S. commune and a solitary isolate of M. palmivorus, all basidiomycetes had low MICs for itraconazole, posaconazole, and voriconazole. Basidiomycetes were isolated from patients with ABPM, invasive pulmonary mycosis/pneumonia, or fungal balls. In addition, the majority of the basidiomycetes were isolated from patients with chronic respiratory disorders who were sensitized to one of the basidiomycetous fungi and demonstrated precipitating antibodies against the incriminating fungi, indicating an indolent tissue reaction. Thus, isolation of basidiomycetes from the lower respiratory tract could be significant, and it is important to monitor these patients in order to prevent subsequent lung damage.

Filamentous Basidiomycetes in the Clinical Laboratory

Filamentous basidiomycetes are difficult to identify in the clinical laboratory, mostly due to lack of sporulation, and their role as agents of fungal infection can be difficult to assess. More cases of infection with these agents are being reported as more laboratories gain proficiency with the recognition of their subtle morphologic features and the use of DNA-based methods for identification. Most infections occur in the respiratory tract and sinuses, although brain infection has been reported. Susceptibility testing suggests that these agents will respond well to azole drugs other than fluconazole.

Molecular characterization and in vitro antifungal susceptibility profile of Schizophyllum commune, an emerging basidiomycete in bronchopulmonary mycoses

Schizophyllum commune (n = 30) showed lowest geometric mean MICs of isavuconazole (0.19 μg/ml), itraconazole (0.2 μg/ml), voriconazole (0.24 μg/ml), and amphotericin B (0.29 μg/ml) and high geometric mean MICs of fluconazole (19.39 μg/ml) and flucytosine (17.28 μg/ml). Five cases (of 8) of allergic bronchopulmonary mycosis that were treated with itraconazole had no recrudescence after 6 to 24 months of follow-up. One case each of invasive pulmonary mycosis and fungal ball were treated successfully with voriconazole and itraconazole.