Exome Sequencing of a Blastomycosis Case-Control Cohort From Manitoba and Northwestern Ontario, Canada.

BACKGROUND: Blastomycosis is a pulmonary disease caused by Blastomyces spp., a group of pathogenic dimorphic fungi endemic to a number of geographic regions, specifically Manitoba and northwestern Ontario, Canada. Immunosuppression is a major risk factor affecting disease susceptibility, yet host immunity is not well understood. Genetic immunodeficiencies can also influence disease, with variants in IL6, GATA2 and VDBP shown to influence susceptibility. Additional genetic factors in disease susceptibility and severity remain undetected. Our study seeks to identify potential genetic risk factors in a blastomycosis case-control cohort from Manitoba and northwestern Ontario, Canada. METHODS: Exomes from 18 blastomycosis cases and 9 controls were sequenced, variants were identified and filtered for accuracy and quality. We performed candidate gene prioritisation and variant aggregation to identify genetic associations and explored the full exome dataset. RESULTS: Ninety-nine genetic variants in 42 candidate genes were identified in the exome dataset. No variants associated with susceptibility were identified in a single-variant analysis although two non-synonymous variants in TYK2 were enriched among cases suggesting a possible role in susceptibility. Gene-based association analysis found variants in TLR1 enriched in controls (p = 0.024) suggesting a possible protective effect. Gene cluster analysis identified genetic variants in genes of chromatin remodelling, proteasome and intraflagellar transport significantly enriched in cases (false discovery rates < 14%). CONCLUSIONS: The findings in this study show novel associations with blastomycosis susceptibility. A better understanding of host immunity and genetic predisposition to Blastomyces infection can help to inform clinical practice for improved outcomes.

Vaccination with O-linked Mannans Protects against Systemic Candidiasis through Innate Lymphocyte Populations.

Candida spp. are the fourth leading cause of bloodstream infections in hospitalized patients and the most common cause of invasive fungal infection. No vaccine against Candida spp. or other fungal pathogens of humans is available. We recently discovered the Blastomyces Dectin-2 ligand endoglucanase 2 that harbors antigenic and adjuvant functions and can function as a protective vaccine against that fungus. We also reported that the adjuvant activity, which is mediated by O-mannans decorating the C terminus of Blastomyces Dectin-2 ligand endoglucanase 2, can augment peptide Ag-induced vaccine immunity against heterologous agents, including Cryptococcus, Candida, and influenza. In this article, we report that the O-linked mannans alone, in the absence of any antigenic peptide, can also protect against systemic candidiasis, reducing kidney fungal load and increasing survival in a Dectin-2-dependent manner. We found that this long-term glycan-induced protection is mediated by innate lymphocyte populations including TCR-γδ+ T cells, innate lymphoid cells, and NK cells that subsequently activate and release reactive oxygen species from neutrophils and monocytes. Our findings suggest that Blastomyces O-mannan displayed by Eng2 induces a form of protective trained immunity mediated by innate lymphocyte populations.

Genomic Epidemiology of Large Blastomycosis Outbreak, Ontario, Canada, 2021.

Using phylogenomic analysis, we provide genomic epidemiology analysis of a large blastomycosis outbreak in Ontario, Canada, caused by Blastomyces gilchristii. The outbreak occurred in a locale where blastomycosis is rarely diagnosed, signaling a possible shift in geographically associated incidence patterns. Results elucidated fungal population genetic structure, enhancing understanding of the outbreak.

Disseminated Blastomycosis in an Immunocompetent Patient.

Blastomycoses dermatitidis is a dimorphic fungus that can cause disseminated blastomycosis with varying clinical manifestations and multiorgan involvement. While blastomycosis commonly causes pulmonary disease, extrapulmonary spread can result in skin, bone, and central nervous system involvement. Cutaneous blastomycosis can present as pustular lesions that evolve into ulcerative or verrucous plaques. We present a case of disseminated blastomycosis in an immunocompetent patient with both pulmonary and cutaneous features. The patient developed hypoxic respiratory failure and was subsequently diagnosed with disseminated blastomycosis after undergoing bronchoscopy with bronchial washing. He was found to have ulcerative nasal lesions as part of his disseminated disease. He was successfully treated with amphotericin B and ultimately discharged from the hospital.

Review of Cutaneous Blastomycosis Seen in Wisconsin.

INTRODUCTION: Blastomycosis is a fungal infection caused by Blastomyces dermatitidis that is hyperendemic in Wisconsin. It commonly presents as a pulmonary infection and frequently disseminates to the skin. Studies evaluating the presentation and diagnosis of blastomycosis with skin as a presenting sign have not been thoroughly evaluated, and understanding the most accurate way to diagnose this infection is important for earlier therapeutic intervention. METHODS: This is a retrospective chart review study of a single institution. Subjects were identified through a search of ICD-9 (International Classification of Diseases, Ninth Revision) and ICD-10 (International Classification of Diseases, Tenth Revision) codes for blastomycosis in the clinical record and pathology database. Patients were included if diagnosed with cutaneous blastomycosis infection or involvement of the skin from systemic infection from January 1, 2009, to June 1, 2021. RESULTS: Twenty patients with a diagnosis of cutaneous involvement of blastomycosis were identified; 65% (n = 13) were male. Median age of diagnosis was 55.5 years. Fifty-five percent of patients were White, 35% were Black or African American. In addition to residence in an endemic area, 50% (n = 10) had exposure risk factors. Fifty percent of patients (n = 10) initially presented with a skin concerns; 65% (n = 13) had extracutaneous involvement. Diagnosis was made by histopathology alone in 55% (n = 11), culture plus histopathology in 35% (n = 7), and culture alone in 5% (n = 1) of cases. CONCLUSIONS: Our study highlighted similarities to those previously performed. Half of the patients (n = 10) who had cutaneous involvement of blastomycosis did not demonstrate clinically significant pulmonary involvement. Histopathology and culture remain critical in diagnosing cutaneous blastomycosis.

Clinical Presentation of Blastomycosis is Associated With Infecting Species, Not Host Genotype.

Objective: To determine if host genetics may be a risk factor for severe blastomycosis.Design: A cohort of patients who had contracted blastomycosis underwent targeted SNP (single nucleotide polymorphism) genotyping. The genetics of these patients were compared to a set of age and gender-matched controls and between patients with severe versus mild to moderate blastomycosis.Setting: The Marshfield Clinic Health System in central and northern WisconsinParticipants: Patients with a diagnosis of blastomycosis prior to 2017 were contacted for enrollment in this study. A phone hotline was also set up to allow interested participants from outside the Marshfield Clinic Health System to request enrollment.Methods: SNP frequency was assessed for significant differences between the patient cohort and controls and between patients with severe versus mild to moderate blastomycosis. We also tested the effect of Blastomyces species identified in clinical isolates on disease symptoms and severity.Results: No significant differences were found in SNP frequency between cases and controls or between those with severe or mild to moderate blastomycosis. We did detect significant differences in symptom frequency and disease severity by Blastomyces species.Conclusions: Our study did not identify any genetic risk factors for blastomycosis. Instead, the species of Blastomyces causing the infection had a significant effect on disease severity.

Beware of the Acute Respiratory Distress Syndrome in a Pulmonary Blastomycosis!

Blastomyces dermatitidis is a dimorphic fungus that can range from mild to severe disease presentation, including the acute respiratory distress syndrome (ARDS) based on the individual's immunity. Acute respiratory distress syndrome is an uncommon presentation having an incidence of about 10% to 15% but has a high mortality exceeding 90%. This is a case of a 50-year-old female with past medical history of asthma and type 2 diabetes mellitus who presented to the pulmonology clinic with worsening dyspnea for the last 2 months. She also had a lesion in the left lower back, which was draining purulent fluid. Chest radiographs showed bilateral infiltrates and was started empirically on vancomycin and piperacillin-tazobactam. Bronchoalveolar lavage was done and the cultures grew B dermatitidis. The patient was moved to a higher level of care and given amphotericin B. Unfortunately, the patient experienced septic shock, which later deteriorated into cardiac arrest, ultimately leading to their passing. The importance of early diagnosis of blastomycosis and timely treatment has been emphasized in this case report.

Detection of Blastomyces gilchristii via metagenomic sequencing in outbreak-associated soils.

Cases of blastomycosis, a serious fungal disease globally rare but endemic to North America, can appear both sporadically and in outbreaks. Tracing these outbreaks to their environment has traditionally used culturing and polymerase chain reaction. Here, we present our method for metagenomic detection of Blastomyces in a 2015 outbreak soil sample from central Wisconsin. By sequencing this sample to multiple depths, we simulated the minimum required depth to detect Blastomyces in this outbreak. Our methods and recommendations can be used to identify the sources of blastomycosis during outbreaks and to learn about the ecology of Blastomyces.

Epistaxis and Facial Swelling Due to Nasal Blastomycosis in a Cat.

A 5 yr old castrated male domestic longhair was examined because of left-sided facial swelling and epistaxis. Head computed tomography with contrast identified a mass within the left nasal cavity and multifocal regions of nasal bone osteolysis. Histopathology of nasal mass biopsies and cytology of the facial swelling revealed pyogranulomatous inflammation due to Blastomyces dermatitidis. The cat experienced resolution of clinical signs following 8 mo of treatment with itraconazole. Although rare, clinicians should include blastomycosis on the differential diagnoses list of infectious causes for feline nasal disease if within an endemic area.

Detection of Histoplasma capsulatum and Blastomyces dermatitidis antigens in serum using a single quantitative enzyme immunoassay.

Histoplasma and Blastomyces antigen detection assays are commonly used diagnostic tools. However, a high level of cross-reactivity between these antigens prevents definitive pathogen identification by these assays alone. Retrospective analysis of 3,529 patients with Histoplasma and Blastomyces antigen testing performed on the same serum sample yielded an overall percent agreement of 99.3% (3,506 of 3,529; kappa: 0.859) between the two assays, suggesting that use of a single assay to detect both antigens may be an alternative diagnostic approach. We assessed performance of the Gotham BioTech Blastomyces antigen (GBA) enzyme immunoassay (EIA) (Portland, Maine) for detection of Blastomyces and Histoplasma antigens in serum. Comparison to the MiraVista Diagnostics Blastomyces (MVB) EIA showed 100% positive (24 of 24), negative (57 of 57), and overall (81 of 81) percent agreement. Additionally, 171 sera were used to compare the GBA EIA to the MiraVista Diagnostics Histoplasma (MVH) EIA, which showed 91.3% (63 of 69), 98% (100 of 102), and 95.3% (163 of 171) positive, negative, and overall percent agreement, respectively. Among eight patients with discordant GBA/MVH EIA results, seven had additional fungal testing performed, and results suggested that the MVH and GBA results were inaccurate for two and five samples, respectively. Overall, this study suggests that the GBA EIA has a high level of agreement with both of the commonly used, individual Blastomyces and Histoplasma antigen EIAs. By taking advantage of the high level of cross-reactivity between Blastomyces and Histoplasma antigen EIAs, utilization of a single antigen detection assay for these fungi provides an opportunity to optimize test utilization and decrease patient cost while maintaining a high level of diagnostic accuracy.

In vitro manogepix susceptibility testing of South African Emergomyces africanus, Emergomyces pasteurianus, and Blastomyces emzantsi clinical isolates.

We performed in vitro antifungal susceptibility testing of manogepix against the yeast phase of 78 Emergomyces africanus, 2 Emergomyces pasteurianus, and 5 Blastomyces emzantsi isolates using a reference broth microdilution method following Clinical and Laboratory Standards Institute recommendations. All three pathogens had low minimum inhibitory concentrations ranging from <0.0005 to 0.008 mg/L. Manogepix should be investigated in animal models and potentially in future human clinical trials for endemic mycoses.

Structure of the imine reductase from Ajellomyces dermatitidis in three crystal forms.

The NADPH-dependent imine reductase from Ajellomyces dermatitidis (AdRedAm) catalyzes the reductive amination of certain ketones with amine donors supplied in an equimolar ratio. The structure of AdRedAm has been determined in three forms. The first form, which belongs to space group P3121 and was refined to 2.01 Šresolution, features two molecules (one dimer) in the asymmetric unit in complex with the redox-inactive cofactor NADPH4. The second form, which belongs to space group C21 and was refined to 1.73 Šresolution, has nine molecules (four and a half dimers) in the asymmetric unit, each complexed with NADP+. The third form, which belongs to space group P3121 and was refined to 1.52 Šresolution, has one molecule (one half-dimer) in the asymmetric unit. This structure was again complexed with NADP+ and also with the substrate 2,2-difluoroacetophenone. The different data sets permit the analysis of AdRedAm in different conformational states and also reveal the molecular basis of stereoselectivity in the transformation of fluorinated acetophenone substrates by the enzyme.

A case series and literature review of blastomycosis during pregnancy amidst the COVID-19 crisis.

Blastomycosis dermatitidis is a rare fungus known for is classic mimicry of pneumonia, lung cancer, and mycobacterial infections. Whilst it is known best for affecting those in the Ohio and Mississippi River basins, several cases have erupted in the Midwest region. Few case reports have focused on blastomycosis and its sequalae in pregnancy. We present a case series of blastomycosis diagnosed during the second and third trimesters in two women amidst the COVID-19 pandemic. Given immunosuppression, complications and treatment can be challenging for clinicians. This case series and discussion hopes to provide future clinicians with the presentation, diagnosis, management, and treatment of this uncommon infection.

First Japanese case of disseminated blastomycosis imported from North America: A case report.

Blastomycosis is a fungal infectious disease that can occur in both immunocompromised and immunocompetent populations endemic in North America, with no previous reports in Japan. A 26-year-old Japanese female patient with no relevant medical history presented intermittent left back pain and an abnormal shadow in the left upper lung field eight months ago at a local clinic. She was referred to our hospital for further evaluation and treatment. The patient currently lives in Japan, but until two years ago had spent several years in New York, Vermont and California. Chest computed tomography revealed a 30 mm mass with a cavity in the left pulmonary apex. The specimens obtained by transbronchial biopsy showed periodic acid-Schiff stain (PAS)-positive and Grocott-positive yeast-like fungi scattered among the granulomas, with no malignant findings, and the initial pathology did not lead to a definitive diagnosis. She was empirically started on fluconazole because of onset of multiple subcutaneous abscesses and was referred to the Medical Mycology Research Center. Although antibody tests could not diagnose the disease, blastomycosis was suspected based on the pathology of the skin and lung tissue at the Medical Mycology Research Center, and Blastomyces dermatitidis was identified by ITS analysis of the rRNA region. Her symptoms and CT findings gradually improved with fluconazole. We reported the first Japanese case of blastomycosis with pulmonary and cutaneous involvement in Japan. As the number of overseas travelers is expected to continue increasing, we would like to emphasize the importance of travel history interviews and information of blastomycosis.

Blastomyces dermatitidis Septic Arthritis in a Renal Transplant Patient.

Blastomycosis is a rare endemic fungal infection caused by the dimorphic fungus Blastomyces dermatitidis. It is more likely to occur in persons living in areas of the United States and Canada, which border the Ohio and Mississippi River Valleys and the Great Lakes region. Most infections are localized to the lungs, often presenting as acute or chronic pneumonia. Occasionally, patients progress to develop disseminated disease and extrapulmonary infections. Blastomycosis tends to be misdiagnosed initially at clinical evaluation as it is rare and may resemble other common conditions. We present a case of a 78-year-old immunosuppressed renal transplant patient who was suspected of having gout but eventually was diagnosed with an unusual presentation of septic arthritis of the ankle secondary to blastomycosis.

Classical Presentation of Disseminated Blastomycosis in a 44-Year-Old Healthy Man 3 Months After Diagnosis of COVID-19.

BACKGROUND During the COVID-19 pandemic, the incidence of opportunistic infections, including fungal infections, has increased. Blastomycosis is caused by inhalation of an environmental fungus, Blastomyces dermatides, which is endemic in parts of the USA and Canada. This case report is of a 44-year-old man from the American Midwest who presented with disseminated blastomycosis infection 3 months following a diagnosis of COVID-19. CASE REPORT Our patient initially presented to an outpatient clinic with mild upper-respiratory symptoms. He tested positive for SARS-CoV-2 via polymerase chain reaction (PCR). Three months later, he presented to our emergency department due to some unresolved COVID-19 symptoms and the development of a widely disseminated, painful rash of 1-week duration. A positive Blastomyces urine enzyme immunoassay was the first indication of his diagnosis, which was followed by the identification of the pathogen via fungal culture from bronchoscopy samples and pathology from lung and skin biopsies. Given the evidence of dissemination, the patient was treated with an intravenous and oral antifungal regimen. He recovered well after completing treatment. CONCLUSIONS The immunocompetent status of patients should not exclude disseminated fungal infections as a differential diagnosis, despite the less frequent manifestations. This is especially important when there is a history of COVID-19, as this may predispose once-healthy individuals to more serious disease processes. This case supports the recent recommendations made by the U.S. Centers for Disease Control and Prevention (CDC) for increased vigilance regarding fungal infections in patients with a history of COVID-19.

UTILITY OF URINE ANTIGEN TESTING FOR DIAGNOSIS OF BLASTOMYCOSIS IN NONDOMESTIC FELIDS.

Blastomycosis caused by the fungus Blastomyces dermatitidis has been reported to cause disease in numerous species of nondomestic felids. Diagnosis of blastomycosis in domestic species often relies on the combination of clinical signs, radiographic findings, and commercial urinary antigen testing. In this report, the sensitivity, specificity, and positive and negative predictive values for urine blastomyces antigen testing for use in nondomestic felids were examined and compared with findings on postmortem examination. The study showed a sensitivity of 100%, specificity of 91.86%, positive predictive value of 50%, and negative predictive value of 100% for urine antigen testing. Furthermore, radiographic and hematologic findings were compared with those of animals diagnosed with blastomycosis. Radiographic evidence consistent with blastomycosis was found in those animals diagnosed via urine antigen testing, but no significant differences in plasma biochemistry parameters between diseased and nondiseased animals were found. This study provides evidence that a positive blastomycosis antigenuria test result should be combined with other diagnostic methods to confirm the presence of infection with B. dermatitidis, whereas a negative antigenuria test result is 100% effective in predicting the absence of disease.

Disseminated Blastomycosis Mimicking Metastatic Head and Neck Cancer in a 70-year-Old Man.

Blastomycosis is a fungal infection known to mimic many disease processes, including malignancy. A 70-year-old man presented with an enlarging neck mass and, incidentally found on preliminary imaging, a lung mass. The initial biopsy of the neck mass demonstrating cytologic atypia and mitotic figures was suggestive of malignancy. Whole body positron emission tomography (PET)/CT revealed hypermetabolic lesions in multiple sites, including the neck, lung, and soft tissue, raising concern for metastatic disease. Repeat sampling from multiple lesions, however, demonstrated granuloma. Microbiological studies were collected, and Blastomyces dermatitidis was isolated in culture. The diagnosis of disseminated blastomycosis was made, and the patient received antifungal therapy with good response. A high degree of suspicion for blastomycosis in endemic areas is required to ensure patients receive appropriate and timely treatment. Laryngoscope, 133:2237-2239, 2023.

Scrotal abscess as an unusual presentation of blastomycosis.

Blastomyces dermatitidis is an environmental fungus endemic to parts of Eastern North America that notably causes pulmonary infection in humans and other animals with the potential for extrapulmonary spread, particularly in immunocompromised hosts. However, it rarely presents with genitourinary (GU) tract involvement. Herein, we present a unique case of a 37-year-old immunocompetent male with genitourinary blastomycosis with the initial presentation of a scrotal abscess.