Fungal infections of the heart: A clinicopathologic study of 50 autopsy cases

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.

Case report: cardiac tamponade secondary to candida pericarditis

Fungal pericarditis, a rare clinical presentation primarily observed in post-cardiothoracic surgery and immunocompromised patients, requires prompt recognition and effective treatment involving antifungal medications and surgical drainage. We report the case of a 40-year-old female initially diagnosed with infective endocarditis who progressed to cardiac tamponade. Timely surgical drainage significantly improved the patient's clinical status and revealed fungal pericarditis through pathological analysis. This case highlights the importance of considering the diagnosis of fungal pericarditis even in the absence of prior cardiothoracic surgical intervention and emphasizes the crucial role of both intravenous antifungal therapy and surgical drainage in its treatment.

GRP78 and Integrins Play Different Roles in Host Cell Invasion during Mucormycosis

Mucormycosis, caused by Rhizopus species, is a life-threatening fungal infection that occurs in patients immunocompromised by diabetic ketoacidosis (DKA), cytotoxic chemotherapy, immunosuppressive therapy, hematologic malignancies, or severe trauma. Inhaled Rhizopus spores cause pulmonary infections in patients with hematologic malignancies, while patients with DKA are much more prone to rhinoorbital/cerebral mucormycosis. Here, we show that Rhizopus delemar interacts with glucose-regulated protein 78 (GRP78) on nasal epithelial cells via its spore coat protein CotH3 to invade and damage the nasal epithelial cells. Expression of the two proteins is significantly enhanced by high glucose, iron, and ketone body levels (hallmark features of DKA), potentially leading to frequently lethal rhinoorbital/cerebral mucormycosis. In contrast, R. delemar CotH7 recognizes integrin β1 as a receptor on alveolar epithelial cells, causing the activation of epidermal growth factor receptor (EGFR) and leading to host cell invasion. Anti-integrin β1 antibodies inhibit R. delemar invasion of alveolar epithelial cells and protect mice from pulmonary mucormycosis. Our results show that R. delemar interacts with different mammalian receptors depending on the host cell type. Susceptibility of patients with DKA primarily to rhinoorbital/cerebral disease can be explained by host factors typically present in DKA and known to upregulate CotH3 and nasal GRP78, thereby trapping the fungal cells within the rhinoorbital milieu, leading to subsequent invasion and damage. Our studies highlight that mucormycosis pathogenesis can potentially be overcome by the development of novel customized therapies targeting niche-specific host receptors or their respective fungal ligands.IMPORTANCE Mucormycosis caused by Rhizopus species is a fungal infection with often fatal prognosis. Inhalation of spores is the major route of entry, with nasal and alveolar epithelial cells among the first cells that encounter the fungi. In patients with hematologic malignancies or those undergoing cytotoxic chemotherapy, Rhizopus causes pulmonary infections. On the other hand, DKA patients predominantly suffer from rhinoorbital/cerebral mucormycosis. The reason for such disparity in disease types by the same fungus is not known. Here, we show that the unique susceptibility of DKA subjects to rhinoorbital/cerebral mucormycosis is likely due to specific interaction between nasal epithelial cell GRP78 and fungal CotH3, the expression of which increases in the presence of host factors present in DKA. In contrast, pulmonary mucormycosis is initiated via interaction of inhaled spores expressing CotH7 with integrin β1 receptor, which activates EGFR to induce fungal invasion of host cells. These results introduce a plausible explanation for disparate disease manifestations in DKA versus those in hematologic malignancy patients and provide a foundation for development of therapeutic interventions against these lethal forms of mucormycosis.

Oral surgery related fungal endocarditis: The need for a novel concept in endocarditis prophylaxy

Current paper aims to hypothesize that, oral surgical interventions such as tooth extractions, endosseous implant placement, subgingival curettage, etc. might result in widespread of fungal species via blood stream and can cause fungal contaminations of the cardiac valves. We hereby suggest that, an additional fungal endocarditis risk assessment and prevention protocol should be created for patients with a possible risk of endocarditis development.

Fulminant Cryptococcus neoformans infection with fatal pericardial tamponade in a patient with chronic myelomonocytic leukaemia who was treated with ruxolitinib: Case report and review of fungal pericarditis

Cryptococcus neoformans is a saprophytic fungal pathogen that can cause serious illness in immune-compromised hosts and it presents with a wide variety of clinical symptoms. We present a fatal case of fulminant C. neoformans infection presenting as pericardial tamponade in a 71-year-old male with chronic myelomonocytic leukaemia undergoing chemotherapy with the JAK-STAT inhibitor ruxolitinib. We also review the published cases of fungal pericarditis/tamponade. In addition to illustrating an atypical presentation of C. neoformans, this case highlights the risk for opportunistic fungal infections in patients with haematological malignancies, especially the ones treated with small molecule kinase inhibitors.

Imaging Spectrum of Invasive Fungal and Fungal-like Infections

Invasive fungal and fungal-like infections contribute to substantial morbidity and mortality in immunocompromised individuals. The incidence of these infections is increasing-largely because of rising numbers of immunocompromised patients, including those with neutropenia, human immunodeficiency virus, chronic immunosuppression, indwelling prostheses, burns, and diabetes mellitus, and those taking broad-spectrum antibiotics. Invasive fungal pathogens include primary mycotic organisms such as Histoplasma capsulatum, Coccidioides immitis, Blastomyces dermatitidis, and Paracoccidioides brasiliensis, which are true pathogens and inherently virulent. Secondary mycotic organisms such as Candida and Aspergillus species, Cryptococcus neoformans, Pneumocystis jirovecii, and Mucorales fungi are opportunistic, less virulent pathogens. Nocardia and Actinomyces species are gram-positive bacteria that behave like fungi in terms of their growth pattern and cause fungal-like invasive indolent infections; thus, these organisms are included in this review. Fungal and fungal-like infections can affect a variety of organ systems and include conditions such as meningitis, sinusitis, osteomyelitis, and enteritis. As awareness of these infections increases, timely diagnosis and treatment will become even more important. Imaging has a critical role in the evaluation of disease activity, therapy response, and related complications. Using an organ-based approach with computed tomography, magnetic resonance imaging, and ultrasonography to gain familiarity with the appearances of these infections enables timely and accurate diagnoses. ^©RSNA, 2017.

Granulomatous myocarditis caused by Candida albicans in a canary (Serinus canaria)

Candida albicans is among the major agents of mucous membrane mycosis in humans and animals, with systemic and deep infections observed in immunocompromised hosts. We describe a case of fatal granulomatous myocarditis caused by C albicans in a 20-day-old canary (Serinus canaria). The etiologic diagnosis was confirmed by identifying characteristic morphologic features of the organism, combined with histochemical staining, and followed by the use of ad hoc biomolecular analysis.