Sensitive bioluminescence imaging of cryptococcosis in Galleria mellonella improves antifungal screening under in vivo conditions

Cryptococcus neoformans is an environmental yeast that primarily affects immunocompromised individuals, causing respiratory infections and life-threatening meningoencephalitis. Treatment is complicated by limited antifungal options, with concerns such as adverse effects, dose-limiting toxicity, blood-brain barrier permeability, and resistance development, emphasizing the critical need to optimize and expand current treatment options against invasive cryptococcosis. Galleria mellonella larvae have been introduced as an ethical intermediate for in vivo testing, bridging the gap between in vitro antifungal screening and mouse studies. However, current infection readouts in G. mellonella are indirect, insensitive, or invasive, which hampers the full potential of the model. To address the absence of a reliable non-invasive method for tracking infection, we longitudinally quantified the cryptococcal burden in G. mellonella using bioluminescence imaging (BLI). After infection with firefly luciferase-expressing C. neoformans, the resulting bioluminescence signal was quantitatively validated using colony-forming unit analysis. Longitudinal comparison of BLI to health and survival analysis revealed increased sensitivity of BLI in discriminating cryptococcal burden during early infection. Furthermore, BLI improved the detection of treatment efficacy using first-line antifungals, thereby benchmarking this model for antifungal testing. In conclusion, we introduced BLI as a real-time, quantitative readout of cryptococcal burden in G. mellonella over time, enabling more sensitive and reliable antifungal screening.

Subacute Hydrocephalus Revealing a Cryptococcus Infection in a Seven-Year-Old Child

Cryptococcal meningitis (CM) is the third most common neurological complication in immunocompromised patients and is usually associated with high rates of morbidity and mortality. The most common complication of CM is intracranial hypertension (ICH), and it constitutes a poor prognosis factor. This case report describes a case of subacute onset hydrocephalus revealing a human immunodeficiency virus (HIV)-associated CM in a seven-year-old girl requiring cerebrospinal fluid diversion and fungal treatment with a favorable outcome.

Chronic Ventriculitis Caused by Cryptococcus neoformans: A Rare Presentation

Cryptococcus neoformans is a fungus notorious for invading the central nervous system. while Cryptococcus is known to cause meningitis, encephalitis, and meningoencephalitis in immunocompromised patients, especially those with AIDS (CD4 <100), and found to be rapidly fatal, instances of ventricular involvement with chronic sequelae are exceedingly rare. Typical presentations of cryptococcal meningitis involve headache, altered mental status, nuchal rigidity, and vomiting. We report a case of a 58-year-old HIV-positive male who presented with intermittent headaches and changes in gait. The MRI revealed ventriculomegaly and advanced chronic sequela of prior ventriculitis with serum and CSF cryptococcal antigen being positive. The treatment of cryptococcal chronic ventriculitis requires a multidisciplinary approach involving internal medicine, neurosurgery, neurology, and infectious diseases. However, this patient's CSF had no pleocytosis and had very high protein, which is a poor prognostic indicator for this disease and could have been prevented with the prompt recognition of the condition before it had progressed to the chronic stage. We recommend that clinicians maintain a high index of suspicion for opportunistic infections, such as cryptococcal meningitis, in any patient with HIV regardless of typical clinical findings.

Cryptococcal endocarditis of native valve in a patient with systemic lupus erythematosus

Cryptococcal endocarditis is an exceedingly rare entity associated with high mortality and morbidity. Hereby, we present a 37-year-old patient with underlying systemic lupus erythematosus and end-stage renal disease who was diagnosed with cryptococcal endocarditis involving native mitral valve. Her blood culture grew Cryptococcus neoformans. Echocardiography confirmed presence of vegetations and patient underwent mitral valve replacement and received appropriate anti-fungal treatment. Her course was further complicated by sternal wound dehiscence and infection of hemodialysis site as well as atrial flutter. Unfortunately, patient passed 2 weeks after discharge from hospital. C. neoformans is typically known to cause serious central nervous system. However, this pathogen can rarely cause serious infective endocarditis case particularly in immune compromised patients or those with prosthetic valves. Fungal endocarditis is usually treated with a combination of surgery and anti-fungal medications.

Disseminated Cryptococcosis Revealing an HIV Infection: A Case Report

Cryptococcosis is a common fungal infection regarded as a disease of immunocompromised patients with high mortality. Cryptococcosis is usually observed in the central nervous system and lungs. However, other organs may be involved such as skin, soft tissue, and bones. Disseminated cryptococcosis is defined as fungemia or the involvement of two distinct sites. Here, we report the case of a 31-year-old female patient with disseminated cryptococcosis with neuro-meningeal and pulmonary involvement revealing a human immunodeficiency virus (HIV) infection. Chest computed tomography scan showed a right apical excavated lesion, pulmonary nodules, and mediastinal lymphadenopathy. Concerning biological tests, hemoculture, sputum, and cerebrospinal fluid (CSF) culture were positive for Cryptococcus neoformans. The latex agglutination test for cryptococcal polysaccharide antigen was positive in CSF and serum and HIV infection was confirmed by serological testing. The patient did not respond to initial antifungal therapy with amphotericin B and flucytosine. Despite the adaptation of antifungal treatment, the patient died of respiratory distress.

Fatal Cryptococcal Meningitis in a Patient With Chronic Lymphocytic Leukemia Treated With Ibrutinib

According to the latest World Health Organization classification published in 2022, chronic lymphocytic leukemia (CLL) is classified as a low-grade proliferation of clonal B-cells. The Bruton tyrosine kinase (BTK) pathway plays a crucial role in B-cell receptor signaling. Ibrutinib, the first irreversible BTK inhibitor, has been shown to improve the survival of CLL patients with lower toxicity than traditional chemotherapy. Cryptococcosis is an invasive fungal infection that primarily affects individuals with compromised immune systems. We present a case of a 69-year-old male with relapsed CLL who received treatment with ibrutinib and subsequently developed meningeal cryptococcosis, presenting with seizures and fever. A physical exam showed bilateral hypoacusis, but no focal deficits. Cerebral imaging was normal and laboratory results showed a low gamma globulin level and leucopenia with lymphopenia but without neutropenia. The cerebrospinal fluid profile was not inflammatory, opening pressure was normal, the classic India ink test was positive, and fungal cultures grew Cryptococcus neoformans. To complete investigations, HIV testing was negative, and sinus and chest tomography scans showed no anomalies. Treatment consisted of discontinuing ibrutinib and administering anti-fungal therapy with liposomal amphotericin (4 mg/kg/day) in combination with flucytosine (25 mg/kg/day). However, the patient's neurological status declined, and he passed away. This case highlights the potential risk of developing opportunistic infections such as cryptococcal meningitis in CLL patients treated with ibrutinib. It is crucial to consider the patient's immune status when administering ibrutinib and to closely monitor for signs of infection.

Comprehensive genome-scale metabolic model of the human pathogen Cryptococcus neoformans: A platform for understanding pathogen metabolism and identifying new drug targets

Introduction: The fungal priority pathogen Cryptococcus neoformans causes cryptococcal meningoencephalitis in immunocompromised individuals and leads to hundreds of thousands of deaths per year. The undesirable side effects of existing treatments, the need for long application times to prevent the disease from recurring, the lack of resources for these treatment methods to spread over all continents necessitate the search for new treatment methods. Methods: Genome-scale models have been shown to be valuable in studying the metabolism of many organisms. Here we present the first genome-scale metabolic model for C. neoformans, iCryptococcus. This comprehensive model consists of 1,270 reactions, 1,143 metabolites, 649 genes, and eight compartments. The model was validated, proving accurate when predicting the capability of utilizing different carbon and nitrogen sources and growth rate in comparison to experimental data. Results and Discussion: The compatibility of the in silico Cryptococcus metabolism under infection conditions was assessed. The steroid and amino acid metabolisms found in the essentiality analyses have the potential to be drug targets for the therapeutic strategies to be developed against Cryptococcus species. iCryptococcus model can be applied to explore new targets for antifungal drugs along with essential gene, metabolite and reaction analyses and provides a promising platform for elucidation of pathogen metabolism.

Synergistic effect of pyrvinium pamoate and posaconazole against Cryptococcus neoformans in vitro and in vivo

Background

Cryptococcosis is a global invasive mycosis with high rates of morbidity and mortality, especially in AIDS patients. Its treatment remains challenging because of the limited antifungals and their unavoidable toxicity, and as such more efforts need to focus on the development of novel effective drugs. Previous studies have indicated that pyrvinium pamoate (PP) has individual and synergistic fungistatic effect. In this study, the effects of PP alone and in combination with azoles [fluconazole (FLU), itraconazole (ITR), voriconazole (VOR), posaconazole (POS)] or amphotericin B (AmB) were evaluated against Cryptococcus neoformans both in vitro and in vivo.

Methods

A total of 20 C. neoformans strains collected from cryptococcal pneumonia and cryptococcal meningitis were studied. The effects of PP alone, PP-azoles and PP-AmB interactions against C. neoformans were evaluated via the microdilution chequerboard technique, adapted from broth microdilution method according to the CLSI M27-A4. The in vivo antifungal activity of PP alone and in combination with azoles and AmB against C. neoformans infections was evaluated by Galleria mellonella survival assay.

Results

The in vitro results revealed that PP individually was ineffective against C. neoformans (MIC>16 μg/ml). Nevertheless, the synergistic effects of PP with ITR, VOR, POS, FLU or AmB was observed in 13 (65.0%, FICI 0.188-0.365), 3 (15.0%, FICI 0.245-0.301), 19 (95.0%, FICI 0.188-0.375), 7 (35.0%, FICI 0.188-0.375), and 12(60.0%, FICI 0.281-0.375) strains of C. neoformans, respectively. There was no antagonism. The survival rates of larvae treated with PP (3.33%) showed almost no antifungal effective, but the larvae survival rates improved when PP combined with AmB (35% vs. 23.33%), FLU (40% vs. 25%), ITR (48.33% vs. 33.33%), VOR (48.33% vs. 53.33%) and POS (56.67% vs. 36.67%) comparison with AmB or azoles alone, and statistical significance was observed when PP combined with POS versus POS alone (P = 0.04).

Conclusions

In summary, the preliminary results indicated the potential of PP in reduction the MICs of azoles and AmB, also itself against C. neoformans; the combination of PP with AMB, FLU, ITR, VOR and POS improve the survival rates of C. neoformans infection larvae, compared with they are alone. The in vitro and in vivo data show that PP could enhance the activity of POS against C. neoformans. This study contributes with data of PP in combination with classical drugs of choice for cryptococcosis treatment.

A fatal disseminated cryptococcal infection in a patient treated with zanubrutinib for Waldenström's macroglobulinemia

INTRODUCTION

Zanubrutinib is a second generation, irreversible small-molecule Bruton tyrosine kinase inhibitor (BTK) approved for the treatment of Waldenström's macroglobulinemia, mantle cell lymphoma, and marginal zone lymphoma. As a class, BTKs have been linked with an increased risk of respiratory infections in clinical trials.

CASE REPORT

We describe a 75-year-old patient who presented with generalized weakness, fevers, dyspnea, and dry cough four months after starting zanubrutinib therapy for Waldenström's macroglobulinemia. He was subsequently diagnosed with pneumonia. Septic work-up led to diagnosis of disseminated cryptococcal infection, complicated by fungal pneumonia and meningitis.

MANAGEMENT AND OUTCOME

Zanubrutinib was held on admission, and the patient was started on combination oral and intravenous antifungal therapy. Despite clearance of fungemia, aggressive resuscitation, and appropriate antimicrobial therapy, respiratory status deteriorated requiring intubation. His condition progressed to septic shock, multiorgan failure, and demise.

DISCUSSION/CONCLUSION

We report herein a case of fatal disseminated cryptococcosis in the setting of zanubrutinib use for Waldenström's macroglobulinemia. At the time of diagnosis, his Waldenström's macroglobulinemia was in a partial response. The mechanism by which Bruton tyrosine kinase inhibitors (BTKs) lead to invasive fungal infections in these patients remains to be explored. T- and B-cell immune defects accompanying low-grade B-cell lymphomas may contribute to the severity of these infections.

Cryptococcus neoformans in Association with Dermatophagoides pteronyssinus has Pro- (IL-6/STAT3 Overproduction) and Anti-inflammatory (CCL2/ERK1/2 Downregulation) Effects on Human Bronchial Epithelial Cells

Cryptococcosis (caused, for example, by Cryptococcus neoformans) and allergic asthma (caused, for example, by Dermatophagoides pteronyssinus) target the respiratory tract (the lung and bronchial epithelium). C. neoformans and D. pteronyssinus can coexist in the same indoor environment, and exposure to both can cause alterations in the local airway inflammatory milieu and exacerbation of airway inflammatory diseases. Here, we evaluated the effects of the association between C. neoformans and D. pteronyssinus in the modulation of airway inflammatory responses in an in vitro experimental model using human bronchial epithelial cells. BEAS-2B cells were cultivated and stimulated with D. pteronyssinus (10 μg/mL) and/or C. neoformans (MOI 100) for 24 h. No cytotoxic effect was observed in cells stimulated by C. neoformans and/or D. pteronyssinus. The production of IL-8, IL-6, and/or CCL2, but not IL-10, as well as the activation of NF-kB, STAT3, STAT6, and/or ERK1/2 were increased in cells stimulated by C. neoformans or D. pteronyssinus compared to controls. C. neoformans in association with D. pteronyssinus inhibited the CCL2‑ERK1/2 signaling pathway in cells treated with both pathogens compared to cells stimulated by D. pteronyssinus alone. In addition, their association induced an additive effect on the IL-6/STAT3 signaling pathway in cells compared to cells stimulated with D. pteronyssinus or C. neoformans only. D. pteronyssinus increased the internalization and growth of C. neoformans in BEAS-2B cells. D. pteronyssinus in association with C. neoformans promoted pro- and anti-inflammatory responses, which can modulate cryptococcal infection and asthmaticus status.

An open label randomized controlled trial of tamoxifen combined with amphotericin B and fluconazole for cryptococcal meningitis

Background

Cryptococcal meningitis has high mortality. Flucytosine is a key treatment but is expensive and rarely available. The anticancer agent tamoxifen has synergistic anti-cryptococcal activity with amphotericin in vitro. It is off-patent, cheap, and widely available. We performed a trial to determine its therapeutic potential.

Methods

Open label randomized controlled trial. Participants received standard care - amphotericin combined with fluconazole for the first 2 weeks - or standard care plus tamoxifen 300 mg/day. The primary end point was Early Fungicidal Activity (EFA) - the rate of yeast clearance from cerebrospinal fluid (CSF). Trial registration https://clinicaltrials.gov/ct2/show/NCT03112031.

Results

Fifty patients were enrolled (median age 34 years, 35 male). Tamoxifen had no effect on EFA (-0.48log10 colony-forming units/mL/CSF control arm versus -0.49 tamoxifen arm, difference -0.005log10CFU/ml/day, 95% CI: -0.16, 0.15, p=0.95). Tamoxifen caused QTc prolongation.

Conclusions

High-dose tamoxifen does not increase the clearance rate of Cryptococcus from CSF. Novel, affordable therapies are needed.

Funding

The trial was funded through the Wellcome Trust Asia Programme Vietnam Core Grant 106680 and a Wellcome Trust Intermediate Fellowship to JND grant number WT097147MA.

Imaging of cryptococcus neoformans infection in breasts: A case report

There have been few reports on the imaging characteristics of cryptococcus neoformans (C. neoformans) infection of the breast. Herein, we reported the imaging features of C. neoformans infection of the breast in a 41-year-old woman with immune thrombocytopenic purpura. Bilateral, diffuse, hyperechoic, and well-defined margin lesions were observed on breast ultrasounds. In addition, a global asymmetry in the left breast, and a focal asymmetry in the right breast were observed on mammograms. Breast fine needle aspiration and biopsy results revealed a C. neoformans infection. After 5 months of treatment with oral fluconazole and amphotericin B, the lesion on the right breast disappeared on repeated-breast ultrasounds.

Cryptococcal Meningitis Causing Refractory Hemichorea-Hemiballismus Treated With Pallidotomy

We report a case of a 31-year-old immunocompetent male who presented with altered mental status and agitation requiring intubation. As sedation was weaned, he demonstrated choreiform movements with associated hemiballismus of the right upper and lower extremities, and he was ultimately diagnosed with cryptococcal meningitis. The patient’s chorea did not terminate after the completion of induction antifungal therapy and all pharmacologic options for the management of chorea were ineffective. He underwent a successful unilateral pallidotomy using standard stereotactic methodology targeting the posterior-ventral pallidum, and his choreiform movements dramatically improved post-operatively within 48 hours.

Uniparental nuclear inheritance following bisexual mating in fungi

Some remarkable animal species require an opposite-sex partner for their sexual development but discard the partner’s genome before gamete formation, generating hemi-clonal progeny in a process called hybridogenesis. Here, we discovered a similar phenomenon, termed pseudosexual reproduction, in a basidiomycete human fungal pathogen, Cryptococcus neoformans, where exclusive uniparental inheritance of nuclear genetic material was observed during bisexual reproduction. Analysis of strains expressing fluorescent reporter proteins revealed instances where only one of the parental nuclei was present in the terminal sporulating basidium. Whole-genome sequencing revealed that the nuclear genome of the progeny was identical with one or the other parental genome. Pseudosexual reproduction was also detected in natural isolate crosses where it resulted in mainly MATα progeny, a bias observed in Cryptococcus ecological distribution as well. The mitochondria in these progeny were inherited from the MATa parent, resulting in nuclear-mitochondrial genome exchange. The meiotic recombinase Dmc1 was found to be critical for pseudosexual reproduction. These findings reveal a novel, and potentially ecologically significant, mode of eukaryotic microbial reproduction that shares features with hybridogenesis in animals.

Sexual reproduction enables organisms to recombine their genes to generate progeny that have higher levels of evolutionary fitness. This process requires reproductive cells – like the sperm and egg – to fuse together and mix their two genomes, resulting in offspring that are genetically distinct from their parents.

In a disease-causing fungus called Cryptococcus neoformans, sexual reproduction occurs when two compatible mating types (MATa and MATα) merge together to form long branched filaments called hyphae. Cells in the hyphae contain two nuclei – one from each parent – which fuse in specialized cells at the end of the branches called basidia. The fused nucleus is then divided into four daughter nuclei, which generate spores that can develop into new organisms. In nature, the mating types of C. neoformans exhibit a peculiar distribution where MATα represents 95% or more of the population. However, it is not clear how this fungus successfully reproduces with such an unusually skewed distribution of mating types.

To investigate this further, Yadav et al. tracked the reproductive cycle of C. neoformans applying genetic techniques, fluorescence microscopy, and whole-genome sequencing. This revealed that during hyphal branching some cells lose the nucleus of one of the two mating types. As a result, the nuclei of the generated spores only contain genetic information from one parent.

Yadav et al. named this process pseudosexual reproduction as it defies the central benefit of sex, which is to produce offspring with a new combination of genetic information. Further experiments showed that this unconventional mode of reproduction can be conducted by fungi isolated from both environmental samples and clinical patient samples. This suggests that pseudosexual reproduction is a widespread and conserved process that may provide significant evolutionary benefits.

C. neoformans represents a flexible and adaptable model organism to explore the impact and evolutionary advantages of sex. Further studies of the unique reproductive strategies employed by this fungus may improve the understanding of similar processes in other eukaryotes, including animals and plants. This research may also have important implications for understanding and controlling the growth of other disease-causing microbes.

Pneumococcal Bacteremia and Cryptococcal Meningitis Dual Infection in a Patient With Multiple Myeloma

Infections remain one of the major complications in patients with multiple myeloma, having a significant impact on morbidity and mortality. The increased risk of infection in these patients are a result of various factors contributing to the impairment of immune system caused by the disease and the chemotherapy regimens given during the treatment phases. Here we report a rare case of pneumococcal bacteraemia and cryptococcal meningitis dual infection in a patient with underlying multiple myeloma who had a favourable clinical outcome. This case also serves to highlight the importance of adult vaccinations especially in patients with underlying comorbidities.

High mortality co-infections of COVID-19 patients: mucormycosis and other fungal infections

Severe COVID-19 disease is associated with an increase in pro-inflammatory markers, such as IL-1, IL-6, and tumor necrosis alpha, less CD4 interferon-gamma expression, and fewer CD4 and CD8 cells, which increase the susceptibility to bacterial and fungal infections. One such opportunistic fungal infection is mucormycosis. Initially, it was debated whether a person taking immunosuppressants, such as corticosteroids, and monoclonal antibodies will be at higher risk for COVID-19 or whether the immunosuppresive state would cause a more severe COVID-19 disease. However, immunosuppressants are currently continued unless the patients are at greater risk of severe COVID-19 infection or are on high-dose corticosteroids therapy. As understood so far, COVID-19 infection may induce significant and persistent lymphopenia, which in turn increases the risk of opportunistic infections. It is also noted that 85% of the COVID-19 patients' laboratory findings showed lymphopenia. This means that patients with severe COVID-19 have markedly lower absolute number of T lymphocytes, CD4+T and CD8+ T cells and, since the lymphocytes play a major role in maintaining the immune homeostasis, the patients with COVID-19 are highly susceptible to fungal co-infections. This report is intended to raise awareness of the importance of early detection and treatment of mucormycosis and other fungal diseases, such as candidiasis, SARS-CoV-2-associated pulmonary aspergillosis, pneumocystis pneumonia and cryptococcal disease, in COVID-19 patients, to reduce the risk of mortality.

Multilocus sequence typing (MLST) of clinical and environmental isolates of Cryptococcus neoformans and Cryptococcus gattii in six departments of Colombia reveals high genetic diversity

INTRODUCTION

The average annual incidence of cryptococcosis in Colombia is 0.23 cases per 100,000 inhabitants in the general population, and 1.1 cases per 1000 in inhabitants with Acquired Immune Deficiency Syndrome (AIDS). In addition, the causal fungus has been isolated from the environment, with serotypes A-B and C in different regions. This study aims to determine the genetic association between clinical and environmental isolates of C. neoformans/C. gattii in Colombia.

METHODS

Multilocus sequence typing (MLST) was used to identify possible clones, providing information about the epidemiology, ecology, and etiology of this pathogen in Colombia.

RESULTS

A total of 110 strains, both clinical (n=61) and environmental (n=49), with 21 MLST sequence types (ST) of C. neoformans (n=14STs) and C. gattii (n=7STs) were identified. The STs which shared clinical and environmental isolate sources were grouped in different geographical categories; for C. neoformans, ST93 was identified in six departments, ST77 in five departments; and for C. gattii, ST25 was identified in three departments and ST79 in two.

CONCLUSIONS

High genetic diversity was found in isolates of C. neoformans/gattii by MLST, suggesting the presence of environmental sources harboring strains which may be sources of infection for humans, especially in immunocompromised patients; these data contribute to the information available in the country on the distribution and molecular variability of C. neoformans and C. gattii isolates recovered in Colombia.

Comparison of cryptococcal meningitis in HIV-negative patients with and without lung infections

Objective

To investigate the clinical features and outcomes of cryptococcal meningitis (CM) in HIV-negative patients with and without lung infections.

Methods

We retrospectively reviewed the medical records of HIV-negative patients with CM admitted to two university hospitals in Southwest China over the past 5 years.

Results

Seventy-one patients were included, of whom 35 (49.3%) had lung disease. Compared with patients without lung infection, CM patients with lung infection tended to be male and younger (≤30 years), experienced more fever, less vomiting and fewer central nervous system symptoms; more often had low white blood cell (WBC) counts (<20 × 10⁶/L), and fewer often had ethmoid sinusitis, maxillary sinusitis, paranasal sinusitis, and otitis media. Cryptococcus neoformans isolates from these patients were sensitive to itraconazole, voriconazole, fluconazole, and amphotericin B but resistant to flucytosine. CM patients with lung infection had higher mortality at discharge compared with patients without lung infection (8.6% vs. 0%). Multivariable analyses showed that a WBC count <20 × 10⁶/L was significantly associated with poor treatment outcome (odds ratio 0.01, 95% confidence interval 0–0.83).

Conclusion

HIV-negative CM patients with lung infections tended to be male and younger. Fever, fewer central nervous system symptoms, and WBC counts <20 × 10⁶/L were characteristic of this patient group.

Cryptococcal Choroid Plexitis and Non-Communicating Hydrocephalus

Cryptococcus neoformans is a fungus that commonly invades the central nervous system. While the choroid plexus, the site of the blood-cerebrospinal fluid barrier, serves as one potential entry point for the pathogen, disease involvement of the choroid plexus itself remains a very rare manifestation of Cryptococcus infection. In cases in which choroid plexus involvement blocks cerebrospinal fluid flow, obstructive hydrocephalus may occur. Here we report the case of a 63-year-old woman who presented with choroid plexitis causing obstructive hydrocephalus at the foramen of Monro. Endoscopic biopsy confirmed Cryptococcus neoformans, and the patient was successfully treated with amphotericin, flucytosine, and fluconazole. With proper recognition and treatment of this pathology, patients can fully recover from this condition.

Disseminated Cryptococcosis in a Patient With Metastatic Prostate Cancer Who Died in the Coronavirus Disease 2019 (COVID-19) Outbreak

We report the case of a 61-year-old patient with a history of prostate cancer affected by bone metastasis. He presented to our attention for ulcerous and necrotic cutaneous lesions unresponsive to antibiotics. The spread of cutaneous lesions and the onset of neurological symptoms suggested a cryptococcal disease, which was confirmed by lumbar puncture and cutaneous biopsy. We present the diagnostic and therapeutic approach to this case.

Screening for invasive fungal disease using non-culture-based assays among inpatients with advanced HIV disease at a large academic hospital in South Africa

INTRODUCTION

Despite widespread access to antiretroviral therapy (ART), the burden of advanced HIV disease in South Africa is high. This translates into an increased risk of AIDS-related opportunistic infections, including invasive mycoses.

METHODS

Using a limited number of non-culture-based diagnostic assays, we aimed to determine the prevalence of invasive mycoses and tuberculosis among hospitalised adults with very advanced HIV (CD4 counts < 100 cells/µL) at a large academic hospital. We conducted interviews and prospective medical chart reviews. We performed point-of-care finger stick and serum cryptococcal antigen lateral flow assays; serum (1 → 3) ß-D-glucan assays; urine Histoplasma galactomannan antigen enzyme immunoassays and TB lipoarabinomannan assays.

RESULTS

We enrolled 189 participants from 5280 screened inpatients. Fifty-eight per cent were female, with median age 37 years (IQR: 30-43) and median CD4 count 32 cells/µL (IQR: 13-63). At enrolment, 60% (109/181) were receiving ART. Twenty-one participants (11%) had a diagnosis of an invasive mycosis, of whom 53% (11/21) had cryptococcal disease. Thirteen participants (7%) had tuberculosis and a concurrent invasive mycosis. ART-experienced participants were 60% less likely to have an invasive mycosis than those ART-naïve (adjusted OR: 0.4; 95% CI 0.15-1.0; P = .03). Overall in-hospital mortality was 13% (invasive mycosis: 10% [95% CI 1.2-30.7] versus other diagnoses: 13% (95% CI 8.4-19.3)).

CONCLUSIONS

One in ten participants had evidence of an invasive mycosis. Diagnosis of proven invasive fungal disease and differentiation from other opportunistic infections was challenging. More fungal-specific screening and diagnostic tests should be applied to inpatients with advanced HIV disease.

Synergic effect of simvastatin in combination with amphotericin B against environmental strains of Cryptococcus neoformans from northeastern Brazil: a prospective experimental study

BACKGROUND

Statins are used as cholesterol-lowering drugs and may also have direct antimicrobial effects.

OBJECTIVE

To evaluate synergic interactions between simvastatin and both amphotericin B and fluconazole, against environmental strains of Cryptococcus neoformans isolated from captive birds' droppings.

DESIGNAND SETTING

Experimental study conducted at Federal University of Piauí, Parnaíba, in collaboration with Federal University of Triângulo Mineiro, Uberaba, Brazil.

METHODS

Statin susceptibility tests of Cryptococcus neoformans samples were performed as prescribed in standards. Interactions of simvastatin with amphotericin and fluconazole were evaluated using the checkerboard microdilution method. Presence of these interactions was quantitatively detected through determining the fractional inhibitory concentration index (FICI).

RESULTS

Isolates of Cryptococcus neoformans were obtained from 30 of the 206 samples of dry bird excreta (14.5%) that were collected from pet shops and houses. Ten isolates were selected for susceptibility tests. All of them were susceptible to amphotericin and fluconazole. All presented minimum inhibitory concentration (MIC) > 128 µg/ml and, thus, were resistant in vitro to simvastatin. An in vitro synergic effect was shown through combined testing of amphotericin B and simvastatin, such that six isolates (60%) presented FICI < 0.500. Two isolates showed considerable reductions in MIC, from 1 µg/ml to 0.250 µg/ml. No synergic effect was observed through combining fluconazole and simvastatin.

CONCLUSION

These results demonstrate that simvastatin should be considered to be a therapeutic alternative, capable of potentiating the action of amphotericin B. However, further studies are necessary to clarify the real effect of simvastatin as an antifungal agent.

A Case of Cryptococcal Hepatitis in an HIV Patient with a Negative Serum Cryptococcal Antigen

Infectious Cryptococcus neoformans occurs primarily in immunocompromised patients. The primary organ affected is the lungs, but the infection of the central nervous system (CNS) is also be seen. Disseminated cryptococcosis can involve any organ in the body. However, hepatic involvement is rare. Here we discuss a case of cryptococcal hepatitis in a patient who presented with persistently elevated liver enzymes. A 56-year-old Ecuadorian female with no known past medical history presented with fever, abdominal pain, nausea, unintentional weight loss, and diarrhea for two months. Her liver function tests (LFTs) revealed elevated aspartate aminotransferase (AST: 415 U/L), elevated alanine aminotransferase (ALT: 201 U/L), elevated alkaline phosphatase (ALP: 763 U/L), but normal total bilirubin (0.9 mg/dl). Her HIV antigen screening was reactive, and the absolute cluster of differentiation 4 (CD4) helper count was 22 cell/µL. Over the course of her hospital stay, the patient's liver enzymes continued to trend upward, with negative Histoplasma antibodies and negative serum cryptococcal antigen titers. During the second week of hospitalization, her liver enzymes continued to rise with an ALP of 4046 U/L, AST of 436 U/L, and ALT of 276 U/L. With a persistent elevation of the liver enzymes without any definitive cause, an ultrasound-guided biopsy was performed. Pathology revealed cryptococcal hepatitis, and the patient was started on a 15-day course of amphotericin B with an eight-week course of fluconazole 400 mg with LFTs nearly normalizing at six weeks. This case demonstrates an unusual manifestation of cryptococcosis. Our patient did not present with the typical cryptococcal pulmonary or central nervous system infection. Additionally, our patient's serum cryptococcal antigen titers were negative, but biopsy results revealed cryptococcal hepatitis, despite a very high sensitivity and specificity of the serum cryptococcal antigen test. This case demonstrates the importance of maintaining a broad differential, specifically in immunocompromised patients.

Distribution and Diversity of Cytochrome P450 Monooxygenases in the Fungal Class Tremellomycetes

Tremellomycetes, a fungal class in the subphylum Agaricomycotina, contain well-known opportunistic and emerging human pathogens. The azole drug fluconazole, used in the treatment of diseases caused by some species of Tremellomycetes, inhibits cytochrome P450 monooxygenase CYP51, an enzyme that converts lanosterol into an essential component of the fungal cell membrane ergosterol. Studies indicate that mutations and over-expression of CYP51 in species of Tremellomycetes are one of the reasons for fluconazole resistance. Moreover, the novel drug, VT-1129, that is in the pipeline is reported to exert its effect by binding and inhibiting CYP51. Despite the importance of CYPs, the CYP repertoire in species of Tremellomycetes has not been reported to date. This study intends to address this research gap. Comprehensive genome-wide CYP analysis revealed the presence of 203 CYPs (excluding 16 pseudo-CYPs) in 23 species of Tremellomycetes that can be grouped into 38 CYP families and 72 CYP subfamilies. Twenty-three CYP families are new and three CYP families (CYP5139, CYP51 and CYP61) were conserved across 23 species of Tremellomycetes. Pathogenic cryptococcal species have 50% fewer CYP genes than non-pathogenic species. The results of this study will serve as reference for future annotation and characterization of CYPs in species of Tremellomycetes.

A Unique Case of Cryptococcus and Histoplasmosis Co-infection in an HIV-negative Male on Chronic Steroid Therapy

Histoplasmosis and cryptococcosis are systemic fungal diseases frequently encountered in immunocompromised hosts, particularly in patients with HIV/AIDS with low CD4 counts. However, co-infection with histoplasmosis and cryptococcosis is an uncommon clinical scenario, hence carrying the risk of under diagnosis by medical professionals. For instance, when one infection is identified, most health professionals will have a low suspicion for an additional co-infection. Here, we report the case of a 71-year-old gentleman with a new diagnosis of myasthenia gravis (MG) requiring recent steroid therapy who presented with recurrent respiratory symptoms despite treatment for community acquired pneumonia. Bronchoscopy and bronchoalveolar lavage (BAL) were performed; BAL samples revealed presence of Cryptococcus neoformans and histoplasma antigen (Ag). Serum cryptococcal Ag and urine histoplasma Ag returned positive as well. The patient then required inpatient treatment with amphotericin B, with eventual transition to oral fluconazole at discharge. Pulmonology and Infectious disease consults assisted in appropriate diagnosis and management of this rare presentation. Given the high prevalence of immunocompromised states in a myriad of medical co-morbidities, it is important to highlight this case to create awareness regarding possibility of concomitant systemic fungal diseases.

A Case Report: Tragic Death in a Young Patient with Human Immunodeficiency Virus Due to Cryptococcal Meningitis

Cryptococcal meningitis is a systemic infection that can be seen in immunosuppressed patients. Altered mental status, somnolence, and obtundation are warning signs of poor prognosis or advanced disease processes.

We present a 23-year-old female with a past medical history significant for human immunodeficiency virus (HIV) obtained via vertical transmission who presented to the emergency department (ED) with a gradual onset of worsening headache over 10 days, with blurry vision, photophobia, nausea and vomiting, and progressive memory lapses. Her blood tests, chest plain radiograph, and non-contrast brain computed tomography (CT) were normal. In the ED, she developed a fever of 102°F and became more confused and agitated, with interspersed screaming and yelling. A lumbar puncture (LP) showed elevated white blood cell count and was positive for Cryptococcus neoformans; an opening pressure was unable to be obtained due to patient agitation. Despite prompt intravenous antibiotics and antifungal medications, her short, but tenuous hospital course involved declining mental status, requiring intubation and multiple therapeutic lumbar punctures, with an elevated opening pressure of up to 55 cm H2O. The patient suffered global ischemic encephalopathy and died on hospital day two.

This case highlights the rapid decompensation of a young immunocompromised patient with cryptococcal meningitis, as well as the importance of early disease management and consultation to neurology and neurosurgery services. An important paradigm difference for emergency medicine (EM) physicians in the management of increased intracranial pressure (ICP) in patients with cryptococcal meningitis is avoiding acetazolamide, mannitol, and steroids and considering the indication for neurosurgical interventions for severe cryptococcal meningitis.

Lacunar Stroke in Cryptococcal Meningitis: Clinical and Radiographic Features

OBJECTIVE

Cryptococcal meningitis carries a high mortality, and survivors are left with considerable neurologic sequelae and marked disability. We lack a clear understanding of the pathogenesis of neurologic sequelae and description of stroke features in this population. We aim to describe clinical and radiographic features and predictors of stroke in a cohort of patients with cryptococcal meningitis.

METHODS

We collected key information on patients diagnosed with cryptococcal meningitis at the University of Colorado Hospital between 2000 and 2018 (n = 42). Of those, 32 had neuroimaging studies available. Bivariate and risk ratio estimates regression models were performed to identify predictors of stroke.

RESULTS

We found a 26% ischemic stroke complication rate in individuals with cryptococcal meningitis. Most strokes were acute (75%), lacunar (100%), multiple (88%), bilateral (63%), and involving the basal ganglia (75%). Presence of malignancy (38% versus 8%, P = .085) was higher in stroke in individuals with cryptococcal meningitis, although not statistically significant. Every unit decrease in hemoglobin and serum sodium were predictors for 1.35 and 1.14 times increase in the risk of ischemic stroke, respectively. The presence of hyponatremia carried a RR of 5.7 (95% confidence interval, 1.7-34, P = .005). Cryptococcal meningitis lead to death in 19% of patients and a considerable rate of neurologic sequela among survivors.

CONCLUSIONS

Cryptococcal meningitis carries a high risk of lacunar stroke, particularly in the basal ganglia. Cryptococcal meningitis-associated stroke is common and frequently associated with neurologic disability among survivors. We need to understand the possible role of malignancy, anemia, and hyponatremia in the onset of ischemic stroke.

Diagnostic and therapeutic strategies in cryptococcosis: impact on outcome

Cryptococcosis diagnosis has been recently improved by the use of rapid cryptococcal antigen testing with lateral flow assays, which have proved sensitive and specific. Using "test and treat" screening strategies for cryptococcal disease with these tests has been showed effective in reducing cryptococcal meningitis (CM) in HIV-infected patients. Recommended induction, consolidation, and maintenance therapeutic strategy for CM is widely unavailable and/or expensive in low and middle-income settings. New therapeutic strategies, mostly using reduced duration, have recently shown acceptable outcome or are currently tested. Diagnostic and therapeutic guidelines for cryptococcal disease in limited resources countries are undergoing a paradigmatic shift.

Cryptococcal pathogenic mechanisms: a dangerous trip from the environment to the brain

Cryptococcus neoformans is an opportunistic pathogenic yeast that causes serious infections, most commonly of the central nervous system (CNS). C. neoformans is mainly found in the environment and acquired by inhalation. It could be metaphorically imagined that cryptococcal disease is a "journey" for the microorganism that starts in the environment, where this yeast loads its suitcase with virulence traits. C. neoformans first encounters the infected mammalian host in the lungs, a site in which it must choose the right elements from its "virulence suitcase" to survive the pulmonary immune response. However, the lung is often only the first stop in this journey, and in some individuals the fungal trip continues to the brain. To enter the brain, C. neoformans must "open" the main barrier that protects this organ, the blood brain barrier (BBB). Once in the brain, C. neoformans expresses a distinct set of protective attributes that confers a strong neurotropism and the ability to cause brain colonisation. In summary, C. neoformans is a unique fungal pathogen as shown in its ability to survive in the face of multiple stress factors and to express virulence factors that contribute to the development of disease.

Cryptococcal meningitis complicating sarcoidosis

BACKGROUND

Cryptococcal meningitis is an uncommon but severe complication of sarcoidosis.

METHODS

We present 2 patients with cryptococcal meningitis complicating sarcoidosis and compared findings with 38 cases reported in the literature.

RESULTS

When analyzing our patients and 38 cases reported in the literature, we found that median age of sarcoidosis patients with cryptococcal meningitis was 39 years (range 30-48); 27 of 33 reported cases (82%) had a history of sarcoidosis. Only 16 of 40 patients (40%) received immunomodulating therapy at the time of diagnosis of cryptococcal meningitis. The diagnosis of cryptococcal meningitis was delayed in 17 of 40 patients (43%), mainly because of the initial suspicion of neurosarcoidosis. Cerebrospinal fluid (CSF) examination showed mildly elevated white blood cell count (range 23-129/mm). Twenty-nine of 32 cases (91%) had a positive CSF culture for Cryptococcus neoformans and 25 of 27 cases (93%) had a positive CSF C neoformans antigen test. CD4 counts were low in all patients in whom counts were performed (84-228/mL). Twelve patients had an unfavorable outcome (32%), of which 7 died (19%) and 24 patients (65%) had a favorable outcome. The rate of unfavorable outcome in patients with a delayed diagnosis was 7 of 17 (41%) compared to 5 of 28 (21%) in patients in whom diagnosis was not delayed.

CONCLUSION

Cryptococcal meningitis is a rare but life-threatening complication of sarcoidosis. Patients were often initially misdiagnosed as neurosarcoidosis, which resulted in considerable treatment delay and worse outcome. CSF cryptococcal antigen tests are advised in patients with sarcoidosis and meningitis.

False-negative cerebrospinal fluid fungal culture results following oral antineoplastic therapy with a 5-fluorouracil derivative

WHAT IS KNOWN AND OBJECTIVE

Cryptococcus neoformans, a common opportunistic pathogen among patients with human immunodeficiency virus (HIV) infection, lymphoproliferative disorders and other conditions causing immunosuppression, can be differentiated from other yeasts using biochemical tests as well as culture results and direct histopathological examination.

CASE SUMMARY

We present a case of a 78-year-old man with Cryptococcal meningitis and false-negative cerebrospinal fluid culture results following receipt of capecitabine.

WHAT IS NEW AND CONCLUSION

Patients receiving immunosuppressive agents are at higher risk of developing invasive fungal infections, and all patient medications should be reviewed to identify those with potential antifungal properties.

Cryptococcal osteomyelitis in an adolescent survivor of T-cell acute lymphoblastic leukemia

Cryptococcosis is infrequent in children, and isolated cryptococcal osteomyelitis is rarely encountered. Here, we describe a 14-year-old patient in remission from T-cell acute lymphoblastic leukemia with osteomyelitis because of Cryptococcus neoformans var. grubii. The patient was effectively treated with antifungal therapy.

The phenotype of the Cryptococcus-specific CD4+ memory T-cell response is associated with disease severity and outcome in HIV-associated cryptococcal meningitis

Background. Correlates of immune protection in patients with human immunodeficiency virus (HIV)–associated cryptococcal meningitis are poorly defined. A clearer understanding of these immune responses is essential to inform rational development of immunotherapies.

Methods. Cryptococcal-specific peripheral CD4⁺ T-cell responses were measured in 44 patients with HIV-associated cryptococcal meningitis at baseline and during follow-up. Responses were assessed following ex vivo cryptococcal mannoprotein stimulation, using 13-color flow-cytometry. The relationships between cryptococcal-specific CD4⁺ T-cell responses, clinical parameters at presentation, and outcome were investigated.

Results. Cryptococcal-specific CD4⁺ T-cell responses were characterized by the production of macrophage inflammatory protein 1α, interferon γ (IFN-γ), and tumor necrosis factor α (TNF-α). Conversely, minimal interleukin 4 and interleukin 17 production was detected. Patients surviving to 2 weeks had significantly different functional CD4⁺ T-cell responses as compared to those who died. Patients with a response predominantly consisting of IFN-γ or TNF-α production had a 2-week mortality of 0% (0/20), compared with 25% (6/24) in those without this response (P = .025). Such patients also had lower fungal burdens (10 400 vs 390 000 colony-forming units/mL; P < .001), higher cerebrospinal fluid lymphocyte counts (122 vs 8 cells/μL; P < .001), and a trend toward faster rates of clearance of infection.

Conclusions. The phenotype of the peripheral CD4⁺ T-cell response to Cryptococcus was associated with disease severity and outcome in HIV-associated cryptococcal meningitis. IFN-γ/TNF-α–predominant responses were associated with survival.

Using solid-state NMR to monitor the molecular consequences of Cryptococcus neoformans melanization with different catecholamine precursors

Melanins are a class of natural pigments associated with a wide range of biological functions, including microbial virulence, energy transduction, and protection against solar radiation. Because of their insolubility and structural heterogeneity, solid-state nuclear magnetic resonance (NMR) spectroscopy provides an unprecedented means to define the molecular architecture of these enigmatic pigments. The requirement of obligatory catecholamines for melanization of the pathogenic fungus Cryptococcus neoformans also offers unique opportunities for investigating melanin development. In the current study, pigments produced with L-dopa, methyl-L-dopa, epinephrine, and norepinephrine precursors are compared structurally using (13)C and (1)H magic-angle spinning (MAS) NMR. Striking structural differences were observed for both aromatic and aliphatic molecular constituents of the mature fungal pigment assemblies, thus making it possible to redefine the molecular prerequisites for formation of the aromatic domains of insoluble indole-based biopolymers, to rationalize their distinctive physical characteristics, and to delineate the role of cellular constituents in assembly of the melanized macromolecules with polysaccharides and fatty acyl chain-containing moieties. By achieving an augmented understanding of the mechanisms of C. neoformans melanin biosynthesis and cellular assembly, such studies can guide future drug discovery efforts related to melanin-associated virulence, resistance to tumor therapy, and production of melanin mimetics under cell-free conditions.

Paucity of initial cerebrospinal fluid inflammation in cryptococcal meningitis is associated with subsequent immune reconstitution inflammatory syndrome

BACKGROUND

Cryptococcal meningitis (CM)-related immune reconstitution inflammatory syndrome (IRIS) complicates antiretroviral therapy (ART) in 20%-40% of ART-naive persons with AIDS and prior CM. Pathogenesis is unknown.

METHODS

We compared initial cerebrospinal fluid (CSF) cultures, inflammatory markers, and cytokine profiles in ART-naive patients with AIDS who did or did not subsequently develop IRIS after starting ART. We also compared results obtained at IRIS events or CM relapse.

RESULTS

Of 85 subjects with CM, 33 (39%) developed CM-related IRIS and 5 (6%) developed culture-positive CM relapse. At CM diagnosis, subjects subsequently developing IRIS had less inflammation, with decreased CSF leukocytes, protein, interferon-gamma, interleukin-6, interleukin-8, and tumor necrosis factor-alpha, compared with subjects not developing IRIS (P<.05, for each). Initial CSF white blood cell counts < or =25 cells/microL and protein levels < or =50 mg/dL were associated with development of IRIS (odds ratio, 7.2 [95% confidence interval, 2.7-18.7]; P<.001). Compared with baseline levels, we identified CSF elevations of interferon-gamma, tumor necrosis factor-alpha, granulocyte colony-stimulating factor, vascular-endothelial growth factor, and eotaxin (CCL11) (P<.05, for each) at the time of IRIS but minimal inflammatory changes in those with CM relapse.

CONCLUSIONS

Patients who subsequently develop CM-related IRIS exhibit less initial CSF inflammation at the time of CM diagnosis, compared with those who do not develop IRIS. The inflammatory CSF cytokine profiles observed at time of IRIS can distinguish IRIS from CM relapse.

Acute respiratory failure associated with cryptococcal pneumonia and disseminated cryptococcosis in an AIDS patient

A 36-year-old homosexual Mexican man was admitted to our hospital, with a 30-day history of fever and headache. Upon cerebrospinal fluid examination, the patient's white blood cell count was 1,580/L, total protein was 26 mg/dL, sugar was 17 mg/dL, and his intracranial pressure was 23 cmH2O. The patient was diagnosed with HIV (Human Immunodeficiency Virus) infection by serum Western blotting. Cryptococcus neoformans was isolated in cultures of the patient's blood and cerebrospinal fluids. Chest computerized tomography revealed diffuse reticulonodular infiltration and a ground-glass appearance in both perihilar regions, suggestive of either Pneumocystis carinii pneumonia or cryptococcal pneumonia. On the patient's 6th day in our hospital, bronchoalveolar lavage and transbronchial lung biopsy were conducted via bronchoscopy, and a pathologic examination of lung biopsy specimens revealed signs of cryptococcal pneumonia. This patient died on his 14th day in our hospital, as the result of acute respiratory failure, associated with cryptococcal pneumonia and disseminated cryptococcosis.

Intraabdominal cryptococcal lymphadenitis in a patient with systemic lupus erythematosus

Cryptococcal infection is a rare, yet well recognized complication of systemic lupus erythematosus (SLE). We present a case of mesenteric and retroperitoneal cryptococcal lymphadenitis resulting in the obstruction of the stomach and proximal duodenum in a patient suffering from SLE, while recently she did not receive any immunosuppressive treatment. A 42-yr-old woman was admitted due to high fever and diffuse abdominal pain for three weeks. Abdominal computed tomography (CT) scan showed multiple conglomerated lymphadenopathies in the retroperitoneum and the mesentery resulting in luminal narrowing of the third portion of the duodenum. Cryptococcal lymphadenitis was proven by needle biopsy and she was treated with intravenous liposomal amphotericin B, followed by oral fluconazole. After fourteen-month antifungal therapies, the clinical symptoms and follow-up images improved. This case emphasize that the intrinsic immunological defects of SLE may be directly responsible for the predisposition to fungal infections.