Dematiaceous Molds

Invasive phaeohyphomycosis co-infection with Alternaria spp. and Curvularia spp. in a neutropenic host

Phaeohyphomycoses are infections caused by dark-walled dematiaceous fungi. Alternaria and Curvularia are two genera of dematiaceous molds known to cause invasive fungal rhinosinusitis, particularly in immunocompromised patients. Co-infection with two dematiaceous fungi is rarely reported in the literature. This report describes a case of biopsy proven invasive fungal rhinosinusitis with Alternaria spp. and Curvularia spp. co-infection in a neutropenic host. The infection characteristics, microbiologic findings, and treatment are described.

Dematiaceous fungal infections: clinical and pathologic conundrums

Dematiaceous fungi are defined by pigment within their cell walls. They are increasingly recognised human pathogens, causing a wide range of clinical presentations, from localised subcutaneous infections to disseminated disease in rare cases. We report our institutional experience with diagnosis of dematiaceous fungal infections from 2005 to 2022 and highlight four instructive cases that clinically and pathologically mimicked other diseases for which the diagnosis was confirmed by fungal culture (one case) or supported by PCR with 28S rRNA and internal transcribed spacer primers (three cases). Two patients were immunocompromised and two had presumed exposure to the organism. In each highlighted case, fungal infection was not clinically suspected, and the pathologist was critical in making the diagnosis and ensuring appropriate clinical management, which was supplemented by fungal stains and novel molecular methods.

Comparison of the antifungal activity of the pyrimidine analogs flucytosine and carmofur against human-pathogenic dematiaceous fungi

Chromoblastomycosis (CBM) and pheohyphomycosis (PHM) are the most common implantation mycoses caused by dematiaceous fungi. In the past, flucytosine (5-FC) has been used to treat CBM, but development of resistance is common. Carmofur belongs to the same class as 5-FC and has in vitro inhibitory activity against the main agents of CBM and PHM. The aim of this study was to compare the action of these two pyrimidine analog drugs against CBM and PHM agents. The minimum inhibitory concentration (MIC) and the selectivity index based on cytotoxicity tests of these two drugs against some agents of these mycoses were determined, with carmofur presenting a higher selectivity index than 5-FC. Carmofur demonstrated here synergistic interactions with itraconazole and amphotericin B against Exophiala heteromorpha, Fonsecaea pedrosoi, Fonsecaea monophora, and Fonsecaea nubica strains. Additionally, carmofur plus itraconazole demonstrated here synergism against a Phialophora verrucosa strain. To evaluate the development of carmofur resistance, passages in culture medium containing subinhibitory concentrations of this pyrimidine analog were carried out, followed by in vitro susceptibility tests. Exophiala dermatitidis quickly developed resistance, whereas F. pedrosoi took seven passages in carmofur-supplemented medium to develop resistance. Moreover, resistance was permanent in E. dermatitidis but transient in F. pedrosoi. Hence, carmofur has exhibited certain advantages, albeit accompanied by limitations such as the development of resistance, which was expected as with 5-FC. This underscores its therapeutic potential in combination with other drugs, emphasizing the need for a meticulous evaluation of its application in the fight against dematiaceous fungi.

Invasive fungal infections and oomycoses in cats 2. Antifungal therapy

CLINICAL RELEVANCE

Invasive fungal infections (IFIs) and oomycoses (hereafter termed invasive fungal-like infections [IFLIs]) are characterised by penetration of tissues by fungal elements. The environment is the most common reservoir of infection. IFIs and IFLIs can be frustrating to treat because long treatment times are usually required and, even after attaining clinical cure, there may be a risk of relapse. Owner compliance with medication administration and recheck examinations can also decline over time. In addition, some antifungal drugs are expensive, have variable interpatient pharmacokinetic properties, can only be administered parenterally and/or have common adverse effects (AEs). Despite these limitations, treatment can be very rewarding, especially when an otherwise progressive and fatal disease is cured.

AIM

In the second of a two-part article series, the spectrum of activity, mechanisms of action, pharmacokinetic and pharmacodynamic properties, and AEs of antifungal drugs are reviewed, and the treatment and prognosis of specific IFIs/IFLIs - dermatophytic pseudomycetoma, cryptococcosis, sino-orbital aspergillosis, coccidioidomycosis, histoplasmosis, sporotrichosis, phaeohyphomycosis, mucormycosis and oomycosis - are discussed. Part 1 reviewed the diagnostic approach to IFIs and IFLIs.

EVIDENCE BASE

Information on antifungal drugs is drawn from pharmacokinetic studies in cats. Where such studies have not been performed, data from 'preclinical' animals (non-human studies) and human studies are reviewed. The review also draws on the wider published evidence and the authors' combined expertise in feline medicine, mycology, dermatology, clinical pathology and anatomical pathology.

ABBREVIATIONS FOR ANTIFUNGAL DRUGS

AMB (amphotericin B); FC (flucytosine); FCZ (fluconazole); ISA (isavuconazole); ITZ (itraconazole); KCZ (ketoconazole); PCZ (posaconazole); TRB (terbinafine); VCZ (voriconazole).

Role of cytopathology in diagnosing phaeohyphomycosis masquerading as nerve abscess in a lepromatous leprosy patient: A case report

INTRODUCTION AND IMPORTANCE

Phaeohyphomycosis is a rare fungal infection primarily affecting immunocompromised individuals. Its clinical manifestations are diverse, and diagnosis can be challenging, particularly when lesions mimic other conditions.

CASE PRESENTATION

A 66-year-old male, with a history of irregular leprosy treatment and prolonged steroid use, presented with symptoms suggestive of a nerve abscess. On examination, cystic swellings were observed on the left thumb and leg. Histopathological examination and fine needle aspiration cytology (FNAC) revealed melanized hyphae, leading to a final diagnosis of phaeohyphomycosis. The patient was treated with oral itraconazole, leading to regression in lesion size.

CLINICAL DISCUSSION

Leprosy patients on long-term steroids are especially susceptible. The pathogenicity of these fungi in immunocompetent people is believed to be due to melanin in their cell walls, which defends against host defenses. Diagnosis involves histopathological examinations, staining, and fungal culture. Treatment involves surgical excision and antifungal drugs. If untreated, it can lead to severe complications including fatal brain infections.

CONCLUSION

This case highlights the unusual presentation of phaeohyphomycosis mimicking a nerve abscess in a leprosy patient. It underscores the importance of a high degree of clinical suspicion in diagnosing such rare infections, particularly in immunocompromised individuals. It also emphasizes the value of FNAC in reaching a definitive diagnosis. Prompt diagnosis and appropriate treatment are essential to prevent potentially serious outcomes.

Challenges towards management of CARD9-deficient patients with phaeohyphomycosis: A case report and case series study

BACKGROUND

A number of recalcitrant phaeohyphomycosis cases with a life-threatening prognosis have been observed in CARD9-deficient patients, but little is known about the long-term management strategies that are effective for such intractable individuals.

OBJECTIVES

To study the genetic and immunological mechanisms underlying recalcitrant phaeohyphomycosis and to share our clinical experiences regarding its treatment.

PATIENTS/METHODS

Ten CARD9-deficient patients with recalcitrant phaeohyphomycosis admitted to our centre in the past two decades were followed-up, and their clinical presentations, laboratory findings, treatment and prognoses were analysed; one of them was a novel case of recalcitrant phaeohyphomycosis harbouring CARD9 mutations. Innate and adaptive immunological responses of patient-derived peripheral blood mononuclear cells were evaluated using ELISA and flow cytometry.

RESULTS

We identified a total of seven CARD9 mutations in the ten analysed patients. Moreover, patient-derived cells exhibited a significant impairment of innate and adaptive immune responses upon fungus-specific stimulation. All the patients experienced recurrence and exacerbation; four of them died, two exhibited continued disease progress with unsatisfactory therapeutic efficacy, three showed obvious improvement under maintenance therapy, and only one achieved a clinical cure.

CONCLUSIONS

Our study highlighted that otherwise healthy patients diagnosed with early-onset, unexplained and recalcitrant phaeohyphomycosis should be analysed for CARD9 mutations and immune deficiency. Thereafter, the length and choice of management remain challengeable and must be adjusted based on the clinical presentations and responses of patients over their lifetimes. Although continued posaconazole treatment may be the promising first-line therapy at present, novel strategies are worth exploring.

Not all black fungus is mucormycosis: A challenging case of Medicopsis romeroi

In this case of phaeohyphomycosis, fine needle aspiration cytology enabled a rapid diagnosis and emergent treatment. This infection is quite prevalent in immunocompromised individuals; however, the Medicopsis romeroi species is a rare causative agent. These cases are associated with inadequate response to standard antifungal therapy and require discussion.

Molecular epidemiology of clinical filamentous fungi in Qatar beyond Aspergillus and Fusarium with notes on the rare species

Due to an increasing number of patients at risk (i.e., those with a highly compromised immune system and/or receiving aggressive chemotherapy treatment), invasive fungal infections (IFI) are increasingly being reported and associated with high mortality rates. Aspergillus spp., particularly A. fumigatus, is the major cause of IFI caused by filamentous fungi around the world followed by Fusarium spp., however, other fungi are emerging as human pathogens. The aim of this study was to explore the epidemiology and prevalence of the non-Aspergillus and non-Fusarium filamentous fungi in human clinical samples over an 11-year period in Qatar using molecular techniques. We recovered 53 filamentous fungal isolates from patients with various clinical conditions. Most patients were males (75.5%), 9.4% were immunocompromised, 20.7% had IFI, and 11.3% died within 30 days of diagnosis. The fungal isolates were recovered from a variety of clinical samples, including the nasal cavity, wounds, respiratory samples, body fluids, eye, ear, tissue, abscess, and blood specimens. Among the fungi isolated, 49% were dematiaceous fungi, followed by Mucorales (30%), with the latter group Mucorales being the major cause of IFI (5/11, 45.5%). The current study highlights the epidemiology and spectrum of filamentous fungal genera, other than Aspergillus and Fusarium, recovered from human clinical samples in Qatar, excluding superficial infections, which can aid in the surveillance of uncommon and emerging mycoses.

Cutaneous Phaeohyphomycosis of the Right Hand Caused by Exophiala jeanselmei: A Case Report and Literature Review

Exophiala spp. is increasingly reported as a pathogen causing the cutaneous, subcutaneous or invasive infection. In this report, we present a case of cutaneous phaeohyphomycosis due to E. jeanselmei on the right hand of a farmer, who suffered from this disease three years ago which had not been definitely diagnosed until he was admitted to our hospital. In our hospital, a potential fungal pathogen was observed by histopathological examination, and then was recovered and identified as E. jeanselmei by sequencing its internal transcribed spacer region. After 4 weeks of antifungal treatment, his hand recovered very well. To investigate the in vitro susceptibility of E. jeanselmei isolates to antifungal agents and compare the characteristics of their related infections among immunocompetent and immunocompromised patients, we reviewed 84 cases published in PubMed database between 1980 and 2020.

Dematiaceous fungal infections in solid organ transplantation: systematic review and bayesian meta-analysis

BACKGROUND

Dematiaceous fungi cause a number of infectious syndromes referred to as phaeohyphomycosis among both immunocompetent and immunocompromised hosts. We performed a systematic review to characterize these infections in solid organ transplant recipients (SOTR).

METHODS

We searched PubMed database (last searched 1/6/2022) for English-language reports on dematiaceous fungal infections in SOTR. Included reports needed individualized demographic, treatment, and outcome data; pediatric reports were excluded. A universally applicable bias assessment was performed on reports. Models for infection type and outcome were created using the Bayesian paradigm.

RESULTS

We included 149 reports on 201 cases of dematiaceous fungal infections in SOTR. The mean age was 54 years, 72% were men, and kidney recipients accounted for 61% of cases. Skin and soft tissue infection (SSTI) was the most common infectious syndrome (73%). Death from infection occurred in 7% of cases (14/201), with disseminated (32%) cases having the highest mortality. Our model for infection type predicted the relative probability of central nervous system infection to be highest in liver recipients. Across all transplant types, higher relative probabilities of disseminated and pulmonary infections occur in the early post-transplant period, and the predicted probabilities for these infection types decreased after 100 months post-transplantation.

DISCUSSION

We identified SSTI as the most common dematiaceous fungal infections in SOTR. Disseminated infections carried the worst prognosis. The evidence in this review is limited by the heterogeneity of included cases. No funding source was used, and this review's protocol was not registered. This article is protected by copyright. All rights reserved.

Novel cases of cutaneous phaeohyphomycosis by Alternaria alstromeriae, Epicoccum tritici and Phialemonium obovatum from North India

BACKGROUND

A growing number of non-dermatophytic moulds and yeasts with the ability to act as human pathogens are reported every year. Dematiaceous fungi cause phaeohyphomycosis which encompasses a broad spectrum of diseases ranging from superficial (cutaneous and subcutaneous) to disseminated infections. Such fungal infections are responsible for causing significant morbidity and mortality, frequently in immunocompromised patients and rarely in immunocompetent patients.

OBJECTIVES

To investigate the prevalence of cutaneous mycosis in Jammu district (India) and to isolate and identify the recovered causal agents from the affected skin of the patients.

METHODS

For direct microscopy, 10% KOH was used. Skin samples were collected carefully from the affected areas of suspected patients, followed by the isolation and identification of the causal agents by cultural examination, morphological examination and ITS sequencing.

RESULTS

Herein, we report and describe three new cases of cutaneous phaeohyphomycosis from District Jammu of Union Territory Jammu and Kashmir, India. The age of the patients under study ranged from 17 to 42 years and the duration of infection from 1 to 2 years. The etiological agents that were recovered from the patients under study were Alternaria alstromeriae, Epicoccum tritici and Phialemonium obovatum. These dematiaceous fungal species were isolated from the skin specimen of immunocompetent hosts.

CONCLUSION

Among the three isolated etiological agents, two (Alternaria alstromeriae, Epicoccum tritici) represent new global records and one (Phialemonium obovatum) new record to India as causal agents of cutaneous phaeohyphomycosis. Careful microscopic and mycological examination form the basis of correct diagnosis of such fungal infections in the absence of simple and reliable laboratory tests (serologic or antigen tests).

Recent advances on mycotic keratitis caused by dematiaceous hyphomycetes

Dematiaceous hyphomycetes (DH) are darkly pigmented fungi ubiquitously found all over the world as plant pathogens and saprophytes, and many of the members of this group have emerged as opportunistic pathogens. These fungi are responsible for a wide variety of infections including mycotic keratitis, which is considered as one of the major causes of corneal blindness, particularly in tropical and subtropical countries with an annual global burden of about 1 000 000 patients. The infection is more common in workers working in an outdoor environment. Moreover, trauma is found to be the most important predisposing cause of mycotic keratitis. Considerable delay in diagnosis and scarcity of effective pharmacological drugs are the major factors responsible for increased morbidity and visual impairment. Considering the crucial role of DH in mycotic keratitis, in the present review, we have focused on major DH with special emphasis on their pathogenicity, diagnosis and treatment strategies.

In Vitro Activities of Ravuconazole and Isavuconazole against Dematiaceous Fungi

The in vitro activities of 11 antifungals against 84 dematiaceous fungi were tested. For most tested fungal species, the MIC values of ravuconazole and isavuconazole were lower than those obtained with itraconazole, voriconazole, and posaconazole. Ravuconazole and isavuconazole appear to be more efficient against most dematiaceous fungal infections than the other triazoles. However, some pigmented fungi, such as Bipolaris spicifera and Veronaea botryosa, remain more susceptible to other triazoles or to echinocandins.

Phaeohyphomycosis: Cytomorphologic Evaluation in Eleven Cases

OBJECTIVE

Phaeohyphomycosis caused by phaeoid fungi is a type of mycosis emerging worldwide which causes a wide variety of clinical manifestations.

STUDY DESIGN

A retrospective analysis of 11 cases diagnosed with fungal inflammation on cytology over a period of 6 years (2013-2018) was done along with culture/histopathologic confirmation.

RESULTS

Of the total of 11 cases, 9 cases presented with subcutaneous swellings and 1 case each with brain and lung lesions. The age range was 30-83 years (mean: 53.6); 8 patients were male and 3 were female. Cytologic smears showed fungal profiles with septate tortuous hyphae, as well as swollen and narrow, yeast-like swellings with an irregular breadth of the hyphae in all cases. The fungal profiles were visualized on a Masson-Fontana stain. The background showed inflammatory cells, giant cells, and necrosis in variable proportions. Five cases were diagnosed as phaeohyphomycosis on cytology, whereas 3 cases were misdiagnosed as aspergillus and 2 as candida. In 1 case, typing of the fungus was not done. Histopathology was available in 5 cases, and in all these a diagnosis of phaeohyphomycosis was reached. Ten of the 11 cases had confirmation on fungal culture.

CONCLUSIONS

Phaeoid fungi are rarely seen in routine cytologic practice. Careful evaluation of cytologic smears and an awareness of the characteristic morphologic features of phaeohyphomycosis are helpful in arriving at a correct diagnosis. Fine needle aspiration cytology provides a rapid diagnosis, enabling prompt therapy.

The Phytopathogenic Fungus Pallidocercospora crystallina-Caused Localized Subcutaneous Phaeohyphomycosis in a Patient with a Homozygous Missense CARD9 Mutation

PURPOSE

In the past decade, an increasing number of otherwise healthy individuals suffered from invasive fungal infections due to inherited CARD9 mutations. Herein, we present a patient with a homozygous CARD9 mutation who was suffering from localized subcutaneous phaeohyphomycosis caused by the phytopathogenic fungus Pallidocercospora crystallina which has not been reported to cause infections in humans.

METHODS

The medical history of our patient was collected. P. crystallina was isolated from the biopsied tissue. To characterize this novel pathogen, the morphology was analyzed, whole-genome sequencing was performed, and the in vivo immune response was explored in mice. Whole-exome sequencing was carried out with samples from the patient's family. Finally, the expression and function of mutated CARD9 were investigated.

RESULTS

A dark red plaque was on the patient's left cheek for 16 years and was diagnosed as phaeohyphomycosis due to a P. crystallina infection. Whole-genome sequencing suggested that that this strain had a lower pathogenicity. The in vivo immune response in immunocompetent or immunocompromised mice indicated that P. crystallina could be eradicated within a few weeks. Whole-exome sequencing revealed ahomozygous missense mutation in CARD9 (c.1118G>C p.R373P). The mRNA and protein expression levels were similar among cells carrying homozygous (C/C), heterozygous (G/C), and wild-type (G/G) CARD9 alleles. Compared to PBMCs or neutrophils with heterozygous or wild-type CARD9 alleles, however, PBMCs or neutrophils with homozygous CARD9 alleles showed impaired anti-P. crystallina effects.

CONCLUSION

Localized subcutaneous phaeohyphomycosis caused by P. crystallina was reported in a patient with a homozygous CARD9 mutation. Physicians should be aware of the possibility of a CARD9 mutation in seemingly healthy patients with unexplainable phaeohyphomycosis.

Subcutaneous phaeohyphomycosis due to Cladophialophora bantiana: a first case report in an immunocompetent patient in Latin America and a brief literature review

We report a rare case of subcutaneous phaeohyphomycosis caused by Cladophialophora bantiana in an immunocompetent patient in Amazonas, Brazil. This dematiaceous fungus has been mainly associated with life-threatening infections affecting the central nervous systems of immunosuppressed patients. We present the clinical, laboratory, and therapeutic aspects, and in vitro susceptibility test results for different antifungal drugs. A brief review of the cases reported in the literature over the past 20 years has also been discussed. According to the literature review, the present case is the first report of subcutaneous phaeohyphomycosis due to C. bantiana in an immunocompetent patient in Latin America.

Disseminated melanized fungal infection due to Cladosporium halotolerans in a dog coinfected with canine adenovirus-1 and canine parvovirus-2

This report presents the pathologic findings associated with disseminated infection due to Cladosporium halotolerans in a dog that was simultaneously infected with canine adenovirus-1 (CAdV-1) and canine parvovirus-2 (CPV-2). A 12-year-old, mixed breed dog, with a clinical history of neurological manifestations was submitted for routine autopsy due to poor prognosis. The principal pathologic findings were mycotic necrotizing nephritis, hepatitis, and splenitis with embolic dissemination to the brain resulting in mycotic necrotizing meningoencephalitis, ventriculitis, choroid plexitis, and obstructive hydrocephalus associated with intralesional and intravascular septate pigmented fungi. PCR and sequencing of the ITS region of fungi revealed that the intralesional fungal organisms had 82% nucleotide identity with members of the Cladosporium sphaerospermum complex of organisms. However, a PCR assay and sequencing of the beta tubulin gene confirmed that the organism identified in this dog had 100% nucleotide sequence identity with C. halotolerans. Using immunohistochemistry, intralesional antigens of CAdV-1 were identified within the epithelial cells of the liver and lungs; there was positive immunolabeling for CPV-2 antigens in degenerated cardiomyocytes. These findings confirmed the active participation of C. halotolerans in the development of disseminated cladosporiosis in this dog and represent a rare occurrence of concomitant infection with CAdV-1 and CPV-2.

Phaeohyphomycosis caused by Medicopsis romeroi in solid organ transplant recipients: Report of two cases and comprehensive review of the literature

Medicopsis romeroi is a melanized coelomycetous fungus, mainly found in tropical and subtropical regions and an uncommon cause of infection in solid organ transplant (SOT) recipients. We describe two cases of SOT recipients diagnosed with phaeohyphomycosis due to M romeroi and provide a comprehensive literature review. These infections should be considered in patients native to tropical countries with a localized skin and soft tissue infection. Sequencing is needed for accurate identification of uncommon melanized fungi. Surgical treatment is recommended to cure the infection and co-adjunctive oral antifungals should be considered.

Opportunistic Fungal Infections in Small Animals

Opportunistic fungal infections have long been recognized as rare causes of disease in immunocompetent dogs and cats. Recently, the escalating use of multiagent immunosuppression protocols (especially those that include cyclosporine) has resulted in an increased number of patients with opportunistic fungal infection encountered by small animal practitioners and has altered the typical case phenotype. Based on histologic and cytologic features such as pigmentation, hyphal diameter, and distribution in tissue, these opportunistic mycoses can be placed into categories such as phaeohyphomycosis, hyalohyphomycosis, and eumycotic mycetoma. This review aims to summarize the clinical presentations, methods for diagnosis, treatment recommendations, and prognosis for both immunocompetent and immunosuppressed patients with opportunistic fungal infections. An example case description is included to illustrate the most common current clinical presentation.

MALDI-TOF MS-Based Identification of Melanized Fungi is Faster and Reliable After the Expansion of In-House Database

PURPOSE

Invasive fungal infections caused by melanized fungi are a growing concern. Rapid and reliable identification plays an important role in optimizing therapy. Matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS)-based identification has emerged as a faster and more accurate diagnostic technique. However, lack of a protein extraction protocol and limited database restricts the identification of melanized fungi by MALDI-TOF MS. The study is designed to standardize protein extraction protocol, to enrich the existing, and to create an in-house database for the rapid identification of melanized fungi.

EXPERIMENTAL DESIGN

In this study, 59 sequence-confirmed, melanized fungi were used to expand and to create an in-house database using a modified protein extraction protocol. A total of 117 clinical isolates are further used to validate the created database.

RESULT

Using existing Bruker database, only 29(24.8%) out of 117 moulds could be identified. However, all the isolates are identified accurately by supplementing the Bruker database with the created in-house database. MALDI-TOF MS takes significantly lesser time for identification compared to DNA sequencing.

CONCLUSION AND CLINICAL RELEVANCE

An expanded database with modified protein extraction protocol can reduce significant time to identify melanized fungi by MALDI-TOF MS.

A 53-Year-Old Male with Relapsed Diffuse Large B-Cell Lymphoma on Chemotherapy with a New Leg Lesion

Patients with underlying malignancy who develop new skin findings while acutely ill often require skin biopsy for histologic evaluation and/or culture to reach a diagnosis. Here, we present the case of a 53-year-old male with relapsed diffuse large B-cell lymphoma on chemotherapy who developed new skin lesions on the leg. On exam, there were 2 nickel-sized, erythematous to violaceous round plaques with central necrotic cores on the right lower leg with relatively nonspecific clinical features for which the initial differential diagnosis was broad. Consensus on a diagnosis was reached upon histologic evaluation of his skin biopsy in the context of his clinical setting. This diagnosis led to a change in treatment plan, with subsequent clinical improvement.

Rare fungal infectious agents: a lurking enemy

In the expanding population of immunocompromised patients and those treated in intensive care units, rare fungal infectious agents have emerged as important pathogens, causing invasive infections associated with high morbidity and mortality. These infections may present either as de novo or as breakthrough invasive infections in high-risk patients with hematologic malignancies receiving prophylactic or empirical antifungal therapy or in patients with central venous catheters. Diagnosis and treatment are challenging. Physicians should have a high index of suspicion because early diagnosis is of paramount importance. Conventional diagnostic methods such as cultures and histopathology are still essential, but rapid and more specific molecular techniques for both detection and identification of the infecting pathogens are being developed and hopefully will lead to early targeted treatment. The management of invasive fungal infections is multimodal. Reversal of risk factors, if feasible, should be attempted. Surgical debridement is recommended in localized mold infections. The efficacy of various antifungal drugs is not uniform. Amphotericin B is active against most yeasts, except Trichosporon, as well as against Mucorales, Fusarium, and some species of Paecilomyces and dimorphic fungi. The use of voriconazole is suggested for the treatment of trichosporonosis and scedosporiosis. Combination treatment, though recommended as salvage therapy in some infections, is controversial in most cases. Despite the use of available antifungals, mortality remains high. The optimization of molecular-based techniques, with expansion of reference libraries and the possibility for direct detection of resistance mechanisms, is awaited with great interest in the near future. Further research is necessary, however, in order to find the best ways to confront and destroy these lurking enemies.

In Vitro Activities of Luliconazole, Lanoconazole, and Efinaconazole Compared with Those of Five Antifungal Drugs against Melanized Fungi and Relatives

The in vitro activities of novel azoles compared to those of five antifungal drugs against clinical (n = 28) and environmental (n = 102) isolates of black mold and melanized yeast were determined. Luliconazole and lanoconazole had the lowest geometric mean MICs, followed by efinaconazole, against tested isolates compared to the other drugs. Therefore, it appears that these new imidazole and triazole drugs are promising candidates for the treatment of infections due to melanized fungi and their relatives.

Nucleic acid amplification methodologies for the detection of pulmonary mold infections

INTRODUCTION

The detection of pulmonary mold infections has historically required technically demanding methods obtained through invasive procedures. Nucleic acid amplification assays have the potential to circumvent the technical hurdles associated with diagnosis, but are not without potential pitfalls. Areas covered: In this paper, the authors review new assays for the diagnosis of pulmonary mold infections due to aspergillosis, mucormycosis, and hyalohyphomycoses as well as uncommon infections caused by dematiaceous molds. Expert commentary: Nucleic acid amplification assays have the potential to rapidly identify patients with invasive mycoses and could shorten the time to implementation of appropriate antimicrobial therapy. However, selection of appropriate patient populations will be crucial to ensure the highest Bayesian positive predictive value for any novel diagnostic platform.

A Mycoses Study Group International Prospective Study of Phaeohyphomycosis: An Analysis of 99 Proven/Probable Cases

Background

Phaeohyphomycosis is infection caused by dematiaceous, or darkly pigmented, fungi. The spectrum of disease is broad, and optimal therapy remains poorly defined. The Mycoses Study Group established an international case registry of patients with proven/probable phaeohyphomycosis with the goal of improving the recognition and management of these infections.

Methods

Patients from 18 sites in 3 countries were enrolled from 2009-2015. Cases were categorized as local superficial, local deep (pulmonary, sinus, osteoarticular infections), and disseminated infections. End points were clinical response (partial and complete) and all-cause mortality at 30 days and end of follow-up.

Results

Of 99 patients, 32 had local superficial infection, 41 had local deep infection, and 26 had disseminated infection. The most common risk factors were corticosteroids, solid organ transplantation, malignancy, and diabetes. Cultures were positive in 98% of cases. All-cause mortality was 16% at 30 days and 33% at end of follow-up, and 18 of 26 (69%) with dissemination died. Itraconazole was most commonly used for local infections, and voriconazole was used for more severe infections, often in combination with terbinafine or amphotericin B.

Conclusions

Phaeohyphomycosis is an increasingly recognized infection. Culture remains the most frequently used diagnostic method. Triazoles are currently the drugs of choice, often combined with other agents. Further studies are needed to develop optimal therapies for disseminated infections.

Combination therapy for the treatment of pulmonary mold infections

INTRODUCTION

Pulmonary mold infections are caused by ubiquitous organisms found in soil, water, and decaying vegetation, including Aspergillus spp., the Mucormycetes, hyaline molds, and dematiaceous (black) molds. Areas covered: These infections are often a challenge to diagnose and even more difficult to treat. Recently, antifungal combination therapy has emerged as a promising strategy to treat some forms of invasive mycoses, including pulmonary mold infections. Historically, this approach has been limited due to non-uniform interpretation criteria, variations in pharmacodynamic/pharmacokinetic properties of antifungals used in combination, and an inability to predict clinical success based on in vitro data and animal models. However, recent advances have helped mitigate some of these challenges. Expert commentary: In this paper, we explore what is known about the antifungal combination therapy in the treatment of pulmonary mold infections and explore how it may impact clinical practice. We pay particular attention to novel combinations and the challenges associated with the development of new antifungal agents.

It's not all about us: evolution and maintenance of Cryptococcus virulence requires selection outside the human host

Cryptococcus is predominantly an AIDS-related pathogen that causes significant morbidity and mortality in immunocompromised patients. Research studies have historically focused on understanding how the organism causes human disease through the use of in vivo and in vitro model systems to identify virulence factors. Cryptococcus is not an obligate pathogen, however, as human-human transmission is either absent or rare. Selection in the environment must thus be invoked to shape the evolution of this taxa, and directly influences genotypic and trait diversity. Importantly, the evolution and maintenance of pathogenicity must also stem directly from environmental selection. To that end, here we examine abiotic and biotic stresses in the environment, and discuss how they could shape the factors that are commonly identified as important virulence traits. We identify a number of important unanswered questions about Cryptococcus diversity and evolution that are critical for understanding this deadly pathogen, and discuss how implementation of modern sampling and genomic tools could be utilized to answer these questions. Copyright © 2016 John Wiley & Sons, Ltd.

Use of Fungal Diagnostics and Therapy in Pediatric Cancer Patients in Resource-Limited Settings

Fungal diseases are an important cause of mortality in immunocompromised hosts, and their incidence in pediatric cancer patients in low- to middle-income countries is underestimated. In this review, we present relevant, up-to-date information about the most common opportunistic and endemic fungal diseases among children with cancer, their geographic distribution, and recommended diagnostics and treatment. Efforts to improve the care of children with cancer and fungal disease must address the urgent need for sustainable and cost-effective solutions that improve training, fungal disease testing capability, and the use of available resources. We hope that the collective information presented here will be used to advise healthcare providers, regional and country health leaders, and policymakers of the current challenges in diagnosing and treating fungal infections in children with cancer in low- to middle-income countries.