Disseminated infection caused by Emmonsia pasteuriana in a renal transplant recipient

Emergomycosis, an Emerging Thermally Dimorphic Fungal Infection: A Systematic Review

Emergomycosis is an endemic mycosis caused by the Emergomyces species. Infections due to this agent have been reported globally. Hence, the present systematic review on Emergomyces infections was conducted to study the disease epidemiology, underlying diseases and risk factors, causative agents, and treatment and outcome. The MEDLINE, Scopus, Embase, and Web of Science databases were searched systematically with appropriate keywords from January 1990 to October 2022. A total of 77 cases of emergomycosis were included in the analysis. Emergomycosis was most commonly seen in patients with human immunodeficiency virus (HIV) infection (n = 61, 79.2%) and HIV-uninfected patients with or without other comorbidities (n = 16, 20.8%). The underlying disease and risk factors significantly associated with emergomycosis in the HIV-infected patients were CD4+ T-cell counts less than 100 cells/mm3 (n = 55, 90.2%), anaemia (n = 30, 49.2%), and thrombocytopenia (n = 17, 27.9%), whereas in the HIV-uninfected patients, treatment with immunosuppressive drugs (n = 10, 62.5%), renal disease (n = 8, 50%), transplant recipients (n = 6, 37.5%), and diabetes mellitus (n = 4, 25%) were the significant risk factors associated with emergomycosis. Emergomyces africanus (n = 55, 71.4%) is the most common causative agent, followed by E. pasteurianus (n = 9, 11.7%) and E. canadensis (n = 5, 6.5%). E. africanus was most often isolated from HIV-infected patients (n = 54, 98.2%), whereas E. pasteurianus was most common in HIV-uninfected patients (n = 5, 55.6%). The all-cause mortality rate of the total cohort is 42.9%. No significant variation in the mortality rate is observed between the HIV-infected patients (n = 28, 36.4%) and the HIV-uninfected patients (n = 5, 6.5%). In conclusion, with an increase in the immunosuppressed population across the globe in addition to HIV infection, the case burden of emergomycosis may increase in the future. Hence, clinicians and mycologists should be vigilant and clinically suspicious of emergomycosis, which helps in early diagnosis and initiation of antifungal treatment to prevent disease mortality.

Emergomyces pasteurianus in Man Returning to the United States from Liberia and Review of the Literature

A 65-year-old man with HIV sought treatment for fever, weight loss, and productive cough after returning to the United States from Liberia. Fungal cultures grew Emergomyces pasteurianus, and the patient's health improved after beginning voriconazole. We describe the clinical case and review the literature, treatment, and susceptibilities for E. pasteurianus.

Emergomyces orientalis Emergomycosis Diagnosed by Metagenomic Next-Generation Sequencing

Emergomyces is a newly described dimorphic fungus genus; it may cause fatal infections in immunocompromised patients, but diagnosis is often delayed. We report a case of disseminated emergomycosis caused by the novel species Emergomyces orientalis in a kidney transplant recipient from Tibet. Infection was diagnosed early by metagenomic next-generation sequencing.

Emergomycosis, an Emerging Systemic Mycosis in Immunocompromised Patients: Current Trends and Future Prospects

Recently, the global emergence of emergomycosis, a systemic fungal infection caused by a novel dimorphic fungus Emergomyces species has been observed among immunocompromised individuals. Though initially classified under the genus Emmonsia, a taxonomic revision in 2017 based on DNA sequence analyses placed five Emmonsia-like fungi under a separate genus Emergomyces. These include Emergomyces pasteurianus, Emergomyces africanus, Emergomyces canadensis, Emergomyces orientalis, and Emergomyces europaeus. Emmonsia parva was renamed as Blastomyces parvus, while Emmonsia crescens and Emmonsia sola remained within the genus Emmonsia until a taxonomic revision in 2020 placed both the species under the genus Emergomyces. However, unlike other members of the genus, Emergomyces crescens and Emergomyces sola do not cause disseminated disease. The former causes adiaspiromycosis, a granulomatous pulmonary disease, while the latter has not been associated with human disease. So far, emergomycosis has been mapped across four continents: Asia, Europe, Africa and North America. However, considering the increasing prevalence of HIV/AIDS, it is presumed that the disease must have a worldwide distribution with many cases going undetected. Diagnosis of emergomycosis remains challenging. It should be considered in the differential diagnosis of histoplasmosis as there is considerable clinical and histopathological overlap between the two entities. Sequencing the internal transcribed spacer region of ribosomal DNA is considered as the gold standard for identification, but its application is compromised in resource limited settings. Serological tests are non-specific and demonstrate cross-reactivity with Histoplasma galactomannan antigen. Therefore, an affordable, accessible, and reliable diagnostic test is the need of the hour to enable its diagnosis in endemic regions and also for epidemiological surveillance. Currently, there are no consensus guidelines for the treatment of emergomycosis. The recommended regimen consists of amphotericin B (deoxycholate or liposomal formulation) for 1–2 weeks, followed by oral itraconazole for at least 12 months. This review elaborates the taxonomic, clinical, diagnostic, and therapeutic aspects of emergomycosis. It also enumerates several novel antifungal drugs which might hold promise in the treatment of this condition and therefore, can be potential areas of future studies.

A global view on fungal infections in humans and animals: infections caused by dimorphic fungi and dermatophytoses

Fungal infections are still underappreciated and their prevalence is underestimated, which renders them a serious public health problem. Realistic discussions about their distribution, symptoms, and control can improve management and diagnosis and contribute to refinement of preventive actions using currently available tools. This article represents an overview of dermatophytes and endemic fungi that cause infections in humans and animals. In addition, the impact of climate change on the fungal spread is discussed. The endemic fungal infections characterized in this article include coccidioidomycosis, histoplasmosis, blastomycosis, lobomycosis, emergomycosis and sporotrichosis. Moreover the geographic distribution of these fungi, which are known to be climate sensitive and/or limited to endemic tropical and subtropical areas, is highlighted. In turn, dermatophytes cause superficial fungal infections of skin, hairs and nails, which are the most prevalent mycoses worldwide with a high economic burden. Therefore, the possibility of causing zoonoses and reverse zoonoses by dermatophytes is highly important. In conclusion, the article illustrates the current issues of the epidemiology and distribution of fungal diseases, emphasizing the lack of public programmes for prevention and control of these types of infection.

Re-drawing the Maps for Endemic Mycoses

Endemic mycoses such as histoplasmosis, coccidioidomycosis, blastomycosis, paracoccidioidomycosis, and talaromycosis are well-known causes of focal and systemic disease within specific geographic areas of known endemicity. However, over the past few decades, there have been increasingly frequent reports of infections due to endemic fungi in areas previously thought to be “non-endemic.” There are numerous potential reasons for this shift such as increased use of immune suppressive medications, improved diagnostic tests, increased disease recognition, and global factors such as migration, increased travel, and climate change. Regardless of the causes, it has become evident that our previous understanding of endemic regions for these fungal diseases needs to evolve. The epidemiology of the newly described Emergomyces is incomplete; our understanding of it continues to evolve. This review will focus on the evidence underlying the established areas of endemicity for these mycoses as well as new data and reports from medical literature that support the re-thinking these geographic boundaries. Updating the endemic fungi maps would inform clinical practice and global surveillance of these diseases.

Disseminated Emergomyces pasteurianus Infection in India: A Case Report and a Review

We report here a case of disseminated Emergomyces pasteurianus infection from India in a patient with AIDS. The patient presented with weight loss, dyspnoea and multiple non-tender skin lesions over face, neck and chest over 3 months. The case was diagnosed by microscopy, histopathology of sample and isolation of fungus from skin lesion, breast nodule, bone marrow and sputum. The identification of the isolates was confirmed by sequencing internal transcribed spacer region of rDNA, beta-tubulin, actin and intein PRP8. The patient responded well to intravenous amphotericin B deoxycholate followed by itraconazole therapy.

In vitro activities of nine antifungal agents against rare pathogenic fungi

Purpose. To assess in vitro activities of nine antifungal agents (amphotericin B, fluconazole, voriconazole, itraconazole, posaconazole, caspofungin, micafungin, terbinafine and 5-flucytosine) against 93 strains of rare pathogenic fungi and the combined effects of drug combinations against several multidrug-resistant fungi.Methodology. The broth microdilution method M38-A3 and M27-A4 from the Clinical and Laboratory Standards Institute and the checkerboard method were performed in this study.Results. Low MICs for fluconazole were observed in moulds including Tritirachium oryzae, Exophiala attenuata and yeasts. MICs for amphotericin B>2 µg ml^-1 were found among Aspergillus nidulans, Fusarium napiforme, Trichoderma longibrachiatum, Tritirachium oryzae, Cunninghamella bertholletiae, Cunninghamella phaeospora, Conidiobolus coronatus, Exophiala attenuata, Ochroconis mirabilis and Rhinocladiella basitona. Multidrug resistance was observed in Microascus spp., Lomentospora prolificans and Pythium insidiosum.Conclusion. Our study illustrated in vitro drug susceptibilities of some rare pathogenic fungi, which provide data to guide clinical treatment of fungal infections.

Two cases of Emergomyces pasteurianus infection in immunocompromised patients in the Netherlands

We report two cases of Emergomyces pasteurianus infection in the Netherlands. Both patients were immunocompromised and had pulmonary symptoms. The first patient died due to a pulmonary infection with Es. pasteurianus, concomitant listeriosis, Pseudomonas aeruginosa sepsis and invasive pulmonary aspergillosis. The second patient had pulmonary and subcutaneous lesions, and recovered completely after treatment with posaconazole for 14 months. In both cases, diagnosis of Es. pasteurianus was made with internal transcribed spacer rRNA PCR and culture.

Fatal Emmonsia sp. Infection and Fungemia after Orthotopic Liver Transplantation

We report a fatal case of disseminated Emmonsia sp. infection in a 55-year-old man who received an orthotopic liver transplant. The patient had pneumonia and fungemia, and multisystem organ failure developed. As human habitats and the number of immunocompromised patients increase, physicians must be aware of this emerging fungal infection.

Molecular detection of airborne Emergomyces africanus, a thermally dimorphic fungal pathogen, in Cape Town, South Africa

Emergomyces africanus is a thermally dimorphic fungus that causes a systemic mycosis in immunocompromised persons in South Africa. Infection is presumed to follow inhalation of airborne propagules. We developed a quantitative PCR protocol able to detect as few as 5 Es. africanus propagules per day. Samples were collected in Cape Town, South Africa over 50 weeks by a Burkard spore trap with an alternate orifice. We detected Es. africanus in air samples from 34 days (10%) distributed over 11 weeks. These results suggest environmental exposure to airborne Es. africanus propagules occurs more commonly in endemic areas than previously appreciated.

Antifungal Susceptibility of Emerging Dimorphic Pathogens in the Family Ajellomycetaceae

The in vitro susceptibilities of 24 molecularly identified dimorphic fungi belonging to the genera Adiaspiromyces, Blastomyces, and Emergomyces within the family Ajellomycetaceae were tested against 8 standard antifungal agents using CLSI document M38-A2. Amphotericin B and posaconazole had the lowest geometric mean MICs (<0.05 μg/ml) followed by itraconazole (<0.07 μg/ml), voriconazole (<0.15 μg/ml), and isavuconazole (<0.42 μg/ml) while fluconazole was not active. Micafungin demonstrated good in vitro antifungal activity against Emergomyces (geometric mean minimum effective concentration [GM MEC] 0.1 μg/ml) and Blastomyces (GM MEC <0.017 μg/ml).

Approach to Fungal Infections in Human Immunodeficiency Virus-Infected Individuals: Pneumocystis and Beyond

Many fungi cause pulmonary disease in patients with human immunodeficiency virus (HIV) infection. Pathogens include Pneumocystis jirovecii, Cryptococcus neoformans, Aspergillus spp, Histoplasma capsulatum, Coccidioides spp, Blastomyces dermatitidis, Paracoccidioides brasiliensis, Talaromyces marneffei, and Emmonsia spp. Because symptoms are frequently nonspecific, a high index of suspicion for fungal infection is required for diagnosis. Clinical manifestations of fungal infection in HIV-infected patients frequently depend on the degree of immunosuppression and the CD4⁺ helper T cell count. Establishing definitive diagnosis is important because treatments differ. Primary and secondary prophylaxes depend on CD4⁺ helper T cell counts, geographic location, and local prevalence of disease.

In Vitro Antifungal Susceptibility of Yeast and Mold Phases of Isolates of Dimorphic Fungal Pathogen Emergomyces africanus (Formerly Emmonsia sp.) from HIV-Infected South African Patients

Disseminated emmonsiosis is an important AIDS-related mycosis in South Africa that is caused by Emergomycesafricanus, a newly described and renamed dimorphic fungal pathogen. In vitro antifungal susceptibility data can guide management. Identification of invasive clinical isolates was confirmed phenotypically and by sequencing of the internal transcribed spacer region. Yeast and mold phase MICs of fluconazole, voriconazole, itraconazole, posaconazole, caspofungin, anidulafungin, micafungin, and flucytosine were determined with custom-made frozen broth microdilution (BMD) panels in accordance with Clinical and Laboratory Standards Institute recommendations. MICs of amphotericin B, itraconazole, posaconazole, and voriconazole were determined by Etest. Fifty unique E. africanus isolates were tested. The yeast and mold phase geometric mean (GM) BMD and Etest MICs of itraconazole were 0.01 mg/liter. The voriconazole and posaconazole GM BMD MICs were 0.01 mg/liter for both phases, while the GM Etest MICs were 0.001 and 0.002 mg/liter, respectively. The fluconazole GM BMD MICs were 0.18 mg/liter for both phases. The GM Etest MICs of amphotericin B, for the yeast and mold phases were 0.03 and 0.01 mg/liter. The echinocandins and flucytosine had very limited in vitro activity. Treatment and outcome data were available for 37 patients; in a multivariable model including MIC data, only isolation from blood (odds ratio [OR], 8.6; 95% confidence interval [CI], 1.3 to 54.4; P = 0.02) or bone marrow (OR, 12.1; 95% CI, 1.2 to 120.2; P = 0.03) (versus skin biopsy) was associated with death. In vitro susceptibility data support the management of disseminated emmonsiosis with amphotericin B, followed by itraconazole, voriconazole, or posaconazole. Fluconazole was a relatively less potent agent.

Novel taxa of thermally dimorphic systemic pathogens in the Ajellomycetaceae (Onygenales)

Recent discoveries of novel systemic fungal pathogens with thermally dimorphic yeast-like phases have challenged the current taxonomy of the Ajellomycetaceae, a family currently comprising the genera Blastomyces, Emmonsia, Emmonsiellopsis, Helicocarpus, Histoplasma, Lacazia and Paracoccidioides. Our morphological, phylogenetic and phylogenomic analyses demonstrated species relationships and their specific phenotypes, clarified generic boundaries and provided the first annotated genome assemblies to support the description of two new species. A new genus, Emergomyces, accommodates Emmonsia pasteuriana as type species, and the new species Emergomyces africanus, the aetiological agent of case series of disseminated infections in South Africa. Both species produce small yeast cells that bud at a narrow base at 37°C and lack adiaspores, classically associated with the genus Emmonsia. Another novel dimorphic pathogen, producing broad-based budding cells at 37°C and occurring outside North America, proved to belong to the genus Blastomyces, and is described as Blastomyces percursus.

Endemic Mycoses: What's New About Old Diseases?

Infections with geographically constrained dimorphic fungi cause the endemic mycoses, which include blastomycosis, coccidioidomycosis, emmonsiosis, histoplasmosis, paracoccidioidomycosis, sporotrichosis, and penicilliosis. In the last 5 years, our understanding of the epidemiology, diagnostics, and to a lesser extent management of these diseases has advanced. Specifically, the application of molecular techniques for genotyping fungal pathogens has resulted in the recognition of cryptic species within several genera, including Blastomyces, and Paracoccidioides; the reclassification of Penicillium marneffei, the agent of penicilliosis, to the genus Talaromyces; and the global emergence of dimorphic fungi of the genus Emmonsia, cause disease in immunocompromised persons. New and refined diagnostic tests are available based on the detection of circulating antigens and antibodies, mass spectrometry, and targeted gene amplification. In contrast, the development of new therapeutic options remains stalled, although isavuconazole may hold promise. Finally, advances have been made in the prospect of viable vaccines for preventing animal and human disease.

Disseminated Emmonsia pasteuriana infection in India: a case report and a review

We report here the first case of disseminated Emmonsia pasteuriana infection in a patient with AIDS in India. The patient presented with weight loss, dyspnoea, left-sided chest pain and multiple non-tender skin lesions over face and body for 3 months. Disseminated emmonsiosis was diagnosed on microscopic examination and fungal culture of skin biopsy and needle aspirate of lung consolidation. It was confirmed by sequencing internal transcribed spacer region of rDNA, beta tubulin, actin, and intein PRP8. The patient responded to amphotericin B and itraconazole therapy.