Human Pathogenic Entomophthorales.

The pathogenic entomophthoralean fungi cause infection in insects and mammalian hosts. Basidiobolus and Conidiobolus species can be found in soil and insect, reptile, and amphibian droppings in tropical and subtropical areas. The life cycles of these fungi occur in these environments where infecting sticky conidia are developed. The infection is acquired by insect bite or contact with contaminated environments through open skin. Conidiobolus coronatus typically causes chronic rhinofacial disease in immunocompetent hosts, whereas some Conidiobolus species can be found in immunocompromised patients. Basidiobolus ranarum infection is restricted to subcutaneous tissues but may be involved in intestinal and disseminated infections. Its early diagnosis remains challenging due to clinical similarities to other intestinal diseases. Infected tissues characteristically display eosinophilic granulomas with the Splendore-Höeppli phenomenon. However, in immunocompromised patients, the above-mentioned inflammatory reaction is absent. Laboratory diagnosis includes wet mount, culture serological assays, and molecular methodologies. The management of entomophthoralean fungi relies on traditional antifungal therapies, such as potassium iodide (KI), amphotericin B, itraconazole, and ketoconazole, and surgery. These species are intrinsically resistant to some antifungals, prompting physicians to experiment with combinations of therapies. Research is needed to investigate the immunology of entomophthoralean fungi in infected hosts. The absence of an animal model and lack of funding severely limit research on these fungi.

Visceral basidiobolomycosis: An overlooked infection in immunocompetent children.

Visceral basidiobolomycosis is an unusual fungal infection of viscera caused by saprophyte Basidiobolus ranarum. It is very rare in healthy children and poses a diagnostic challenge due to the non-specific clinical presentation and the absence of predisposing factors. We report a case of gastrointestinal basidiobolomycosis in a 4-year-old healthy girl who presented with a short history of abdominal pain, bleeding per rectum, fever, and weight loss. The diagnosis was based on high eosinophilic count, classical histopathology findings of fungal hyphae (the Splendore-Hoeppli phenomenon), and positive fungal culture from a tissue biopsy. Fungal infection was successfully eradicated with a combined approach of surgical resection of the infected tissue and a well-monitored course of antifungal therapy. The atypical clinical presentation, diagnostic techniques, and the role of surgery in the management of a rare and lethal fungal disease in an immunocompetent child are discussed.

Successful treatment of cutaneous zygomycosis with extensive surgical debridement and oral posaconazole in an immunocompetent patient.

We describe a case of successful treatment of cutaneous zygomycosis using a combination of extensive surgical debridement and the oral antifungal agent, posaconazole.

Zigomicosis cutánea primaria en paciente pediátrica inmunocomprometida / Primary zygomycosis in a pediatric inmunocompromised patient

La zigomicosis es una infección infrecuente causada por hongos oportunistas que pertenecen al orden Mucorales, cuya característica es la invasión vascular por hifas, lo que determina trombosis, infarto y necrosis tisular. En General afecta a pacientes con efermedades subyacentes, causando infecciones invasoras severas y a menudo fulminantes. Algunas condiciones de riesgo son: leucemias y linfomas con neutropenia prolongada, cetoacidosis diabética, malnutrición severa, ruptura de la integridad de la barrera cutánea y terapia inmunosupresora. Se presenta un caso de zigomicosis cutánea primaria en el antebrazo, en una paciente pedíatrica con leucemia linfobástica aguda de tipo B, con grave neutropenia y tratamiento con corticoides, y describimos los aspectos histológicos y clínicos de la lesión necrótica en la zona de punción venosa.

Cutaneous zygomycosis: a possible postoperative complication in immunocompetent individuals.

Fungi in the class of zygomycetes usually produce serious infections in diabetics and immunocompromised hosts. Cutaneous zygomycosis is a less common form, with an unpredictable extent of anatomical involvement and clinical course. Here, we report two cases of primary cutaneous zygomycosis as postoperative complications in otherwise healthy females. Zygomycosis was suspected and specimens from the surgical debridement were examined by microbiological and histopathological studies for confirming the clinical diagnosis. Rapid diagnosis, liposomal amphotericin B, and proper debridement of affected tissue are necessary to avoid a fatal outcome.

The role of neutrophils in the development and outcome of zygomycosis in haematological patients.

Zygomycosis constitutes the third leading cause of invasive fungal infections following aspergillosis and candidosis. Patients with haematologic malignancies or haematopoietic stem cell transplantation are particularly susceptible to zygomycosis. Neutropenia represents the most important pathogenic mechanism influencing the onset and outcome of zygomycosis. Neutrophils cause a lesion of the fungal wall with subsequent destruction by macrophages. They also enhance the activity of antifungal drugs against Zygomycetes. Strategies that aim to increase neutrophil count and function, such as granulocyte colony stimulating factor and granulocyte transfusion, could play an important role in the management of this life-threatening infectious complication.

An unusual case of fungal chorioretinitis in an immunocompetent individual.

PURPOSE: To describe a case of fungal chorioretinitis in a healthy individual. DESIGN: Case report. RESULTS: A 74-year-old immunocompetent man presented with peripheral chorioretinitis with hemorrhage in the superonasal quadrant. A retinal biopsy was performed. PAS and Gomori methenamine silver stain disclosed fungal structures identified as broad nonseptate hyphae with right-angle branches, probably belonging to the Zygomycete class. A systemic workup was initiated to seek the source of the infection with normal findings. The patient was successfully treated with intravitreous and intravenous amphotericine B. CONCLUSION: Nontraumatic fungal chorioretinitis can present in immunocompetent patients.

Primary cutaneous zygomycosis in an immunodeficient infant: a case report and review of the literature.

We report a case of primary cutaneous zygomycosis caused by Rhizopus species in an infant with a hematological malignancy. Multiple surgical debridements, skin grafting, and intravenous antifungal therapy were necessary to ultimately eradicate the infection. Zygomycotic infections are an emerging concern in immunocompromised patients because of their increased incidence as well as their potential to cause substantial morbidity through both emotional distress and impaired functionality. Because resection is a cornerstone of treatment for zygomycosis, the authors anticipate a growing need for plastic surgery involvement for both surgical debridement with limb and tissue-sparing procedures, and for reconstructive options that effectively treat the disease while preserving both function and esthetics. The plastic surgery literature is reviewed regarding surgical and reconstructive options for this population of patients. This case demonstrates the important role plastic surgeons play in the multidisciplinary treatment of zygomycotic and other opportunistic cutaneous infections.

The immune response to fungal infections.

During the past two decades, invasive fungal infections have emerged as a major threat to immunocompromised hosts. Patients with neoplastic diseases are at significant risk for such infections as a result of their underlying illness and its therapy. Aspergillus, Candida, Cryptococcus and emerging pathogens, such as the zygomycetes, dark walled fungi, Trichosporon and Fusarium, are largely opportunists, causing infection when host defences are breached. The immune response varies with respect to the fungal species and morphotype encountered. The risk for particular infections differs, depending upon which aspect of immunity is impaired. This article reviews the current understanding of the role and relative importance of innate and adaptive immunity to common and emerging fungal pathogens. An understanding of the host response to these organisms is important in decisions regarding use of currently available antifungal therapies and in the design of new therapeutic modalities.

Interferon- gamma and granulocyte-macrophage colony-stimulating factor augment the activity of polymorphonuclear leukocytes against medically important zygomycetes.

Zygomycetes cause serious invasive infections, predominantly in immunocompromised and diabetic patients with poor prognoses and limited therapeutic options. We compared the antifungal function of human polymorphonuclear leukocytes (PMNLs) against hyphae of Rhizopus oryzae and R. microsporus, the most frequently isolated zygomycetes, with that against the less frequently isolated Absidia corymbifera. We then evaluated the effects of interferon (IFN)- gamma and granulocyte-macrophage colony-stimulating factor (GM-CSF), alone or combined, on PMNL antifungal function against these zygomycetes. Both PMNL oxidative burst in response to hyphae and PMNL-induced hyphal damage were significantly lower in response to Rhizopus species than in response to A. corymbifera. Incubation of PMNLs with IFN- gamma and GM-CSF alone or combined for 22 h increased the PMNL-induced hyphal damage of all 3 species. The treatment of PMNLs with the combination of IFN- gamma and GM-CSF significantly increased the release of tumor necrosis factor- alpha in response to R. microsporus and A. corymbifera hyphae. IFN- gamma significantly reduced interleukin-8 release in response to all zygomycetes. Although Rhizopus species demonstrate a decreased susceptibility to the antifungal activity of human PMNLs, in comparison with A. corymbifera, IFN- gamma and GM-CSF augment the hyphal damage of all 3 zygomycetes, suggesting a role for IFN- gamma and GM-CSF in the management of invasive zygomycosis.

Antigenic relationship between Loboa loboi and Paracoccidioides brasiliensis as shown by serological methods.

Lobomycosis and paracoccidioidomycosis are two different mycoses caused by Loboa loboi and Paracoccidioides brasiliensis, respectively. To verify cross-antigenicity between them, lobomycosis sera were tested by immunoblotting, ELISA and capture-EIA against crude exo-antigen, 'cell-free antigen' and gp43 from P. brasiliensis. The majority of lobomycosis serum samples recognized crude exo-antigens and gp43 from P. brasiliensis. Gp43 was eluted from an affinity column prepared with IgG from a patient with active lobomycosis. In lower frequencies and intensities, lobomycosis sera also recognized proteins of 29 kDa, 36 kDa, 39 kDa, 52 kDa, 63 kDa, 70 kDa, 83 kDa, and 108 kDa from P. brasiliensis.