Histoplasmosis: A systematic review to inform the World Health Organization of a fungal priority pathogens list.

Histoplasmosis, a significant mycosis primarily prevalent in Africa, North and South America, with emerging reports globally, poses notable health challenges, particularly in immunocompromised individuals such as people living with HIV/AIDS and organ transplant recipients. This systematic review, aimed at informing the World Health Organization's Fungal Priority Pathogens List, critically examines literature from 2011 to 2021 using PubMed and Web of Science, focusing on the incidence, mortality, morbidity, antifungal resistance, preventability, and distribution of Histoplasma. We also found a high prevalence (22%-44%) in people living with HIV, with mortality rates ranging from 21% to 53%. Despite limited data, the prevalence of histoplasmosis seems stable, with lower estimates in Europe. Complications such as central nervous system disease, pulmonary issues, and lymphoedema due to granuloma or sclerosis are noted, though their burden remains uncertain. Antifungal susceptibility varies, particularly against fluconazole (MIC: ≥32 mg/l) and caspofungin (MICs: 4-32 mg/l), while resistance to amphotericin B (MIC: 0.125-0.16 mg/l), itraconazole (MICs: 0.004-0.125 mg/l), and voriconazole (MICs: 0.004-0.125 mg/l) remains low. This review identifies critical knowledge gaps, underlining the need for robust, globally representative surveillance systems to better understand and combat this fungal threat.

Management of disseminated histoplasmosis in a high-complexity clinic in Cali, Colombia.

Histoplasmosis presents a substantial clinical challenge globally, with a particular prevalence in South America, especially among patients with concurrent Human Immunodeficiency Virus (HIV) infection. Despite itraconazole's established efficacy, investigating alternative therapeutic approaches remains imperative. This is the largest study in our region to date, assessing the effectiveness of the less explored posaconazole treatment. This observational study, conducted at Fundación Valle del Lili (FVL) from 2016 to 2022, encompassed adults with disseminated histoplasmosis. Patients (n = 31) were treated with liposomal amphotericin B as an initial treatment, followed by consolidation treatment with posaconazole or itraconazole. Patients with single-organ cases, those lacking microbiological diagnosis, those who received initial treatment with antifungals other than liposomal Amphotericin B and those with < 6 months follow-up were excluded (Figure 1). Analyses considered population characteristics, treatments, and outcomes. Patients (average age: 45.6; 58.1% female) had common comorbidities (HIV 38.7%, solid organ transplantation 29% and oncologic disease 12.9%). Lungs (48.4%) and lymph nodes (16.1%) were commonly affected. Biopsy (64.5%) was the primary diagnostic method. Initial treatment with liposomal amphotericin B (100%) was given for 14 days on average. Follow-up indicated 71% completion with 19.4% requiring treatment modifications. Notably, 70.9% completed a posaconazole consolidation regimen over 350 days on average. Drug interactions during consolidation (80.6%) were common. No relapses occurred, and three deaths unrelated to histoplasmosis were reported. Traditionally, itraconazole has been the prevalent initial treatment; however, in our cohort, 55.9% of patients received posaconazole as the primary option. Encouragingly, posaconazole showed favorable tolerance and infection resolution, suggesting its potential as an effective and well-tolerated alternative for consolidation treatment. This finding prompts further exploration of posaconazole, potentially leading to more effective patient care and better outcomes.

Histoplasmosis is a critical concern in South America, notably among human immunodeficiency virus patients, leading to high mortality rates. This study, the largest in our region, investigates the effectiveness of posaconazole as an alternative treatment to itraconazole. The results offer the potential for enhanced patient care and improved outcomes.

Antifungal Susceptibility Testing and Drug Discovery in the Dimorphic Fungus Histoplasma Capsulatum.

The thermal dimorphism of the fungal pathogen Histoplasma is linked to its virulence in mammalian hosts. Mammalian body temperature triggers differentiation of the fungus into virulent yeasts which successfully infect host phagocytes. Accurate determination of antifungal susceptibility with relevance to infection requires that the tests be performed specifically using the yeast form, not the filamentous environmental form. However, traditional CLSI methodology for antifungal susceptibility testing of yeasts with Histoplasma is in adequate. We present optimized methodology for performing antifungal susceptibility assays on Histoplasma yeasts with an emphasis on quantitative yeast growth determination. Colorimetric and fluorometric assays for Histoplasma growth overcome challenges associated with quantifying some Histoplasma strains which grow as aggregates of yeasts. We also describe antifungal susceptibility testing of Histoplasma yeasts within macrophages to provide improved accuracy and better physiological relevance of antifungal susceptibility profiles.

A metabolic inhibitor arms macrophages to kill intracellular fungal pathogens by manipulating zinc homeostasis.

Macrophages deploy numerous strategies to combat invasion by microbes. One tactic is to restrict acquisition of diverse nutrients, including trace metals, a process termed nutritional immunity. Intracellular pathogens adapt to a resource-poor environment by marshaling mechanisms to harvest nutrients. Carbon acquisition is crucial for pathogen survival; compounds that reduce availability are a potential strategy to control intracellular replication. Treatment of macrophages with the glucose analog 2-deoxy-D-glucose (2-DG) armed phagocytes to eliminate the intracellular fungal pathogen Histoplasma capsulatum in vitro and in vivo. Killing did not rely on altering access to carbon-containing molecules or changes in ATP, ER stress, or autophagy. Unexpectedly, 2-DG undermined import of exogenous zinc into macrophages, decreasing the quantity of cytosolic and phagosomal zinc. The fungus perished as a result of zinc starvation. This change in metal ingress was not ascribed to a defect in a single importer; rather, there was a collective impairment in transporter activity. This effect promoted the antifungal machinery of macrophages and expanded the complexity of 2-DG activities far beyond manipulating glycolysis. Mechanistic metabolic studies employing 2-DG will have to consider its effect on zinc transport. Our preclinical data support consideration of this agent as a possible adjunctive therapy for histoplasmosis.

Histoplasmosis in the Republic of Congo dominated by African histoplasmosis, Histoplasma capsulatum var. duboisii.

The Republic of Congo (RoC) is one of the African countries with the most histoplasmosis cases reported. This review summarizes the current status regarding epidemiology, diagnostic tools, and treatment of histoplasmosis in the RoC. A computerized search was performed from online databases Medline, PubMed, HINARI, and Google Scholar to collect literature on histoplasmosis in the RoC. We found 57 cases of histoplasmosis diagnosed between 1954 and 2019, corresponding to an incidence rate of 1-3 cases each year without significant impact of the AIDS epidemic in the country. Of the 57 cases, 54 (94.7%) were cases of Histoplasma capsulatum var. duboisii (Hcd) infection, African histoplasmosis. Three cases (5.3%) of Histoplasma capsulatum var. capsulatum infection were recorded, but all were acquired outside in the RoC. The patients' ages ranged between 13 months to 60 years. An equal number of cases were observed in adults in the third or fourth decades (n = 14; 24.6%) and in children aged ≤15 years. Skin lesions (46.3%), lymph nodes (37%), and bone lesions (26%) were the most frequent clinical presentations. Most diagnoses were based on histopathology and distinctive large yeast forms seen in tissue. Amphotericin B (AmB) was first line therapy in 65% of the cases and itraconazole (25%) for maintenance therapy. The occurrence of African histoplasmosis in apparently normal children raises the possibility that African histoplasmosis is linked to environmental fungal exposure.

Media matters! Alterations in the loading and release of Histoplasma capsulatum extracellular vesicles in response to different nutritional milieus.

Histoplasma capsulatum is a dimorphic fungus that most frequently causes pneumonia, but can also disseminate and proliferate in diverse tissues. Histoplasma capsulatum has a complex secretion system that mediates the release of macromolecule-degrading enzymes and virulence factors. The formation and release of extracellular vesicles (EVs) are an important mechanism for non-conventional secretion in both ascomycetes and basidiomycetes. Histoplasma capsulatum EVs contain diverse proteins associated with virulence and are immunologically active. Despite the growing knowledge of EVs from H. capsulatum and other pathogenic fungi, the extent that changes in the environment impact the sorting of organic molecules in EVs has not been investigated. In this study, we cultivated H. capsulatum with distinct culture media to investigate the potential plasticity in EV loading in response to differences in nutrition. Our findings reveal that nutrition plays an important role in EV loading and formation, which may translate into differences in biological activities of these fungi in various fluids and tissues.

Bilateral adrenal histoplasmosis presenting as adrenal insufficiency in an immunocompetent host in the Philippines.

Disseminated histoplasmosis, with the adrenal glands as being the only site of demonstrable disease in an immunocompetent adult, is a rare infection leading to adrenal insufficiency. This disease carries high mortality when unrecognised. We describe the first reported case of adrenal histoplasmosis in the Philippines in a 72-year-old immunocompetent, Filipino man who presented with a 3-month history of intermittent flank pain, weight loss and generalised weakness. His imaging demonstrated bilateral adrenal masses on ultrasonography and contrast-enhanced CT scan. The initial impression was adrenal cancer, however, fine-needle aspiration cytology revealed the presence of yeast cells and blood culture grew Histoplasma capsulatum The diagnosis of the case represents a diagnostic challenge in immunocompetent individuals because they manifest with non-specific symptoms. A heightened suspicion is therefore needed to prevent significant morbidity and mortality.

Pyrexia of unknown origin in HIV-negative adults from Himachal Pradesh (India): will you suspect disseminated histoplasmosis?

Histoplasmosis is usually clinically suspected only in people who reside in, are migrants from or are travelling to endemic areas such as North America. Immunocompetent patients with a low level of exposure typically have either subclinical or mild and self-limiting infection. The most common risk for the development of progressive disseminated form is HIV infection. We recently managed two patients with disseminated histoplasmosis, presenting with prolonged fever, significant weight loss, pallor and hepatosplenomegaly. Both were HIV-negative and lived in Himachal Pradesh (India), a region that was considered "Histoplasma-free" until recently.

Fever of Unknown Origin in a Renal Transplant Recipient: Lactate Dehydrogenase as an Important Clue to Diagnosis.

Histoplasmosis is a rare disease in nonendemic areas. We report a case of a 23-year-old male patient who presented with fever of unknown origin, cytopenias, organomegaly, and allograft dysfunction 4 months after renal transplant with father as donor. Bone marrow examination showed intracellular budding yeast cells, which was confirmed as histoplasmosis by culture of bone marrow biopsy sample. The patient was treated with intravenous liposomal amphotericin and responded well.

Histoplasmosis: epidemiología, diagnóstico y terapéutica / Histoplasmosis: epidemiology, diagnosis and therapy

La histoplasmosis es una enfermedad granulomatosa, producida por hongos dimorfos del género Histoplasma. Se observa en casi todos los países del mundo. En América Latina, en Venezuela, Colombia, Brasil, Argentina, Ecuador, Perú, Paraguay y Uruguay, entre otros. Datos epidemiológicos recienteshanmostrado un aumento de histoplasmosis en Venezuela y otros países.Los clínicos no están conscientes de su importancia en nuestro medio. Objetivo: Dar a conocer la situación actual de esta enfermedad en el Area Metropolitana de Caracas y en otras áreas endémicas, con la intención de crear la inquietud de investigar su incidencia y otras características relevantes en el resto del país. Métodos: Se analizaron las características de todos los pacientes con diagnóstico de certeza de histoplasmosis registrados y realizados por la Sección de Micología Médica ­Dr. Dante Borelli‖ del Instituto de Medicina Tropical de la UCV, referidos de los diferentes hospitales del Distrito Capital y otros estados del país, con énfasis en los datos epidemiológicos, manifestaciones clínicas, diagnóstico, tratamiento y evolución entre 1994 y 2012. Resultados: se encontraron 553 pacientes. La mayoría estaban entre los 20 y 49 años, relacionado con un alto número de pacientes con VIH/SIDA. Hubo más casos en hombres que en mujeres en todos los grupos etarios, menos en los pacientes mayores de 60 años, posiblemente debido a la disminución de los estrógenos, que son protectores en la mujer. Casi todos los pacientes con VIH/SIDA mostraron la forma diseminada, solo uno presentó una forma pulmonar. De los pacientes VIH negativos, 54,62% presentaron infección diseminada y 44,47%, formas pulmonares. 93 de los de enfermedad diseminada tenían estados de inmunocompromiso. El examen directo fue el método más fácil y eficaz para diagnosticar la histoplasmosis. La anfotericina B (AMB) fue el tratamiento para la histoplasmosis en pacientes con o sin SIDA, que requirieron hospitalización, seguido por itraconazol (ITC). Esta droga se utilizó en pacientes que no se encontraban severamente enfermos o con afectación del sistema nervioso central. Conclusiones: histoplasmosis se encuentra en aumento en nuestro país. Se observa con más frecuencia en pacientes con SIDA, inmunosuprimidos y pacientes que han recibido un inóculo abundante. El examen directo con coloraciones especiales es el método de mayor rendimiento para el diagnóstico. Este debe ser realizado por personal con experiencia.Es conveniente utilizar diferentes técnicas para aumentar la probabilidad de obtener un diagnóstico correcto. AMB e ITC son los tratamientos de elección. Los médicos deben estar alertas de los signos y síntomas, correlacionándolos con los antecedentes epidemiológicos, para evitar el retraso del diagnóstico y mejorar la evolución de los pacientes.

Histoplasmosis is a granulomatous disease, caused by dimorphic fungi from the genus Histoplasma. It is described worldwide.In Latin America, Venezuela, Colombia, Brasil, Argentina, Ecuador, Perú, Paraguay and Uruguay among others are affected. Recent epidemiological data have shown an increase of histoplasmosis in Venezuela and other countries. Clinicians are nor aware of the importance of this mycosis. Objective: analyze the current situation of this disease in the Caracas Metropolitan Area and other endemic areas, with intention to create awareness of its incidence and other relevant characteristics in our country. Methods: characteristics of the patients with diagnosis of histoplasmosis, performed and registered at the Sección de Micología Médica ­Dr. Dante Borelli‖, Instituto de Medicina Tropical, UCV, referred from different hospitals at Distrito Capital and other states of the country, with emphasis on epidemiological data, clinical manifestations, diagnosis, treatment and outcome, between 1994 and 2012 are analized. Results: 553 patients were found. Most of them were between 20 and 49 years old, possibly due to a high number of HIV/AIDS patients. There were more male than female patients in all age groups, except in 60 years and older, possibly due to the lack of estrogenic hormones, which protect women from infection. All HIV/AIDS patients but one, presented with a disseminated form of the disease, and one, a pulmonary form. Of the HIV negative patients, 54,62% showed disseminated infection and 44,47%, pulmonary presentation. 93 of the disseminated infection patients had immunocompromising conditions. Direct examination was the easiest and most efficacious diagnostic method. Amphotericin B (AMB) was the drug of choice for the treatment of hospitalized patients, followed by Itraconazole (ITC). This was the preferred treatment for mild to moderate disease or non CNS infection. Conclusions: Histoplasmosis is rising in our country. It is more frequent in HIV/AIDS patients and immune suppression. It is also seen in patients who have inhaled a large inoculum. Direct examination with special stains is the diagnostic method with better results. It must be performed by experienced personnel in fungal diagnosis. The use of different techniques is recommended to improve early and correct diagnosis. AMB and ITC are drugs of choice for the treatment of histoplasmosis. Clinicians should be aware of suggestive symptoms and signs, correlating them with epidemiological data, to avoid diagnostic delay and improve the outcome of the patients.

Modification of the Francis Medium for the Conversion of Histoplasma capsulatum to the Yeast-Like Growth Phase.

We propose a modification of Francis agar used for identification of the causative agent of histoplasmosis by in vitro conversion of the mycelial culture to the yeast-like growth phase. For improving of the growth characteristics of the medium, we used FT-agar with glucose-vitamin additives developed for culturing of the tularemia causative agent. The modified Francis medium is characterized by significantly higher growth properties and allowed 10-fold increasing the number of CFU of yeast-like cells of both American and African histoplasmosis causative agent.

Laryngeal histoplasmosis in a kidney transplant recipient.

Histoplasma capsulatum is an endemic fungus that most oftenly causes a self-limiting illness but can result in severe infections in immunocompromised patients including pulmonary or extra-pulmonary disease. Rarely it can also cause a chronic progressive infection of the larynx. Herein, we report a case of laryngeal histoplasmosis in a kidney transplant patient who presented with progressive symptoms of several weeks of hoarseness, dysphagia and odynophagia. Laryngoscopic examination revealed thick plaques in the oropharynx with surrounding hyper-erythema and histopathology showed numerous intracellular yeasts forms consistent with H capsulatum. Patient was initiated on treatment with itraconazole. Infection of the larynx due to H capsulatum is highly uncommon and therefore can result in an inappropriate or delayed diagnosis. A review of literature showed four previously reported cases of laryngeal histoplasmosis in patients with solid organ transplant. This is the first case series of laryngeal histoplasmosis in transplant recipients.

Clinical outcomes and cortical reserve in adrenal histoplasmosis-A retrospective follow-up study of 40 patients.

OBJECTIVE: Detailed studies of Addison's disease resulting from disseminated adrenal histoplasmosis (AH) are not available. We describe the presentation and prognosis of AH and cortisol status before and after antifungal therapy. DESIGN: Single-centre retrospective hospital-based study of 40 consecutive adults with AH [39 males; age (mean ± SD) 53 ± 11 years] was conducted between 2006 and 2018. The median duration of follow-up was 2.5 years (range 0.2-12 years). PATIENTS AND METHODS: AH was diagnosed by bilateral adrenal enlargement on CT scan and presence of Histoplasma by histology and/or culture of biopsied adrenal tissue. All patients received oral itraconazole and, if required, amphotericin B as per guidelines. ACTH-stimulated serum cortisol (normal > 500 nmol/L) was measured in 38 patients at diagnosis and re-tested after one year of antifungal therapy in 21 patients. RESULTS: Seventy-three per cent of patients had primary adrenal insufficiency (PAI) and one-third had an adrenal crisis at presentation. HIV antibody was negative in all patients. Of the 29 patients who completed antifungal therapy, 25 (86%) were in remission at last follow-up. Overall, 8 (20%) patients died: three had a sudden death, four had severe histoplasmosis and one died due to adrenal crisis. No patient with PAI became eucortisolemic on re-testing after one year of antifungal therapy. Of the eight patients with normal cortisol at diagnosis, two developed adrenal insufficiency on follow-up. CONCLUSION: All patients with AH tested negative for HIV antibody. While patients achieved a high rate of clinical remission after antifungal therapy, overall mortality was significant. Cortisol insufficiency did not normalize despite treatment.

Case Report: Hemophagocytic Lymphohistiocytosis Caused by Disseminated Histoplasmosis in a Venezuelan Patient with HIV and Epstein-Barr Virus Reactivation Who Traveled to Japan.

We describe a Venezuelan visitor to Japan who was diagnosed with hemophagocytic lymphohistiocytosis (HLH). The patient was also diagnosed with human immunodeficiency virus (HIV) and Epstein-Barr virus infection by the Western blot and polymerase chain reaction (PCR) tests, respectively. The cause of HLH was considered to be these two infections at first; however, the patient did not recover with antiretroviral/anti-herpes virus therapy. Thereafter, diagnosis of disseminated histoplasmosis was confirmed with an antigen detection test, culture, and PCR test of blood, urine, and bone marrow, and the patient improved gradually after the initiation of liposomal amphotericin B. This case highlights the importance of ruling out endemic mycosis as a cause of HLH even if other probable causes exist in patients from endemic areas.

Onydecalins, Fungal Polyketides with Anti- Histoplasma and Anti-TRP Activity.

We report an unusual 3-substituted pyridine polyketide, onydecalin A (1), which was obtained along with 2 as a major constituent from the fungus Aioliomyces pyridodomos (order: Onygenales) following a two-month fermentation. Feeding studies demonstrated that the pyridine subunit originates via an unprecedented biosynthetic process in comparison to other polyketide-linked pyridines or derivatives such as pyridones. The slow growth of the fungus led us to perform a one-year fermentation, leading to production of compounds 2-4 as the major constituents. These compounds showed modest but selective inhibition against a variety of transient receptor potential channels, as well as against the human pathogenic fungus Histoplasma capsulatum.

Paracoccidioides spp. and Histoplasma capsulatum: Current and New Perspectives for Diagnosis and Treatment.

The thermally-dimorphic systemic fungal group includes several important human pathogens: Blastomyces dermatitides, Coccidioides immitis and C. posadasii, Histoplasma capsulatum, Paracoccidioides brasiliensis, P. lutzii, and Talaromyces (Penicillium) marneffei. They usually are geographically restricted and have natural habitats in soil or in plants, and when fungal propagules invade mammalian host by inhalation, they initiate an inflammatory reaction that can result in self-resolution of the infection or cause an acute or chronic disease. In the setting of the AIDS pandemic and the developments in modern medicine, such as immunosuppressive therapy in cancer surgery patients and in transplantation and autoimmune diseases, the incidence of endemic mycoses has progressively increased. Another important factor of the increased incidence of systemic mycoses in certain regions is the progressive devastation of tropical and subtropical forests. In this review, we focus on two of the most important systemic mycoses: paracoccidioidomycosis and histoplasmosis, and their major characteristics in epidemiology, clinical aspects and laboratorial diagnosis.

A case of Histoplasma capsulatum variety capsulatum septic arthritis successfully treated with surgery, systemic antifungals, and local amphotericin cement beads.

Histoplasma capsulatum variety capsulatum (H. capsulatum) is a thermally dimorphic fungus that is endemic to the Mississippi River and Ohio River valley regions. Of the hundreds of thousands of patients exposed to this fungus, less than 1% develop a severe illness most commonly manifesting as pulmonary disease. Septic arthritis from hematogenous seeding with H. capsulatum or from direct inoculation has been reported only rarely in the literature. The first case of septic arthritis of the shoulder due to H. capsulatum occurring in an immunocompromised patient, treated successfully with irrigation and debridement, systemic antifungals, and local delivery of amphotericin B with cement beads, is reported here. Importantly, the addition of local amphotericin B delivery by cement beads to conventional treatment likely led to clinical cure in this patient.

A proposal for antifungal epidemiological cut-off values against Histoplasma capsulatum var. capsulatum based on the susceptibility of isolates from HIV-infected patients with disseminated histoplasmosis in Northeast Brazil.

Epidemiological cut-off values (ECVs) have been used as a tool to detect the acquisition of resistance mechanisms to antifungal drugs. In this context, the objective of this study was to determine the ECVs for classic antifungals against Histoplasma capsulatum var. capsulatum isolates from human immunodeficiency virus (HIV)-infected patients with a diagnosis of disseminated histoplasmosis. First, minimum inhibitory concentrations (MICs) for amphotericin B (AmB), itraconazole (ITR), fluconazole (FLU), voriconazole (VCZ) and caspofungin (CAS) were determined against 138 H. capsulatum isolates in the filamentous form by the broth microdilution method; antifungal ECVs were then calculated. MIC ranges were 0.0078-1 µg/mL for AmB, 0.0005-0.0625 µg/mL for ITR, 2 to ≥256 µg/mL for FLU, 0.0078-1 µg/mL for VCZ and ≤0.0156 to ≥32 µg/mL for CAS. The obtained ECVs were 0.5, 0.0313, 128, 0.5 and 16 µg/mL for AmB, ITR, FLU, VCZ and CAS, respectively. The percentage of wild-type isolates was 96.4% for AmB, 98.6% for ITR and 99.3% for FLU, VCZ and CAS. Although these results do not cover all phylogenetic species of H. capsulatum, they bring important information on strains from Brazil. In addition, the assessed isolates were from HIV-positive patients, which may not reflect the antifungal ECVs against isolates from immunocompetent individuals or from other sources. Finally, this study pioneers the initiative of establishing ECVs for five antifungal agents against H. capsulatum var. capsulatum, providing a criterion for the interpretation of susceptibility results as well as a monitoring strategy for the emergence of antifungal resistance.

Synthesis and biological evaluation of aminothiazoles against Histoplasma capsulatum and Cryptococcus neoformans.

The design and synthesis of a library of forty novel 2-aminoazole analogues as well as their evaluation as antifungal compounds against Histoplasma capsulatum and Cryptococcus neoformans is described. These structures were derived from N-[5-(1-naphthalenylmethyl)-2-thiazolyl]cyclohexanecarboxamide (41F5), a fungistatic agent previously identified through phenotypic screening (Antimicrob Agents Chemother. 2013;57:4349). Modifications to improve potency and water-solubility of 41F5 focused primarily on the 5-naphthalenyl group, the thiazole core, and the methylene linker between these two structural elements. In general, compounds with lipophilic [5+6] bicyclic ring systems, such as the 7-benzothiophenyl- and 4-indanyl groups, at the 5-position were 2-3 times more active against both fungal species as compared to 41F5. Also, introduction of a carbonyl group at the methylene linker of 41F5 resulted in a 2-3-fold increase in potency. These highly active compounds also showed generally low toxicities against murine P388D1 macrophages resulting in selectivity indices ranging from 63 to >200. Compounds that were highly active against fluconazole-sensitive C. neoformans strains had almost identical activity against fluconazole-resistant variants of this fungus indicating that 14α-demethylase is not their molecular target. Highly active compounds also retained activity against H. capsulatum phagocytosed into P388D1 macrophages.