An update on Cryptococcus among HIV-infected patients

Cryptococcosis-a systematic review to inform the World Health Organization Fungal Priority Pathogens List

Cryptococcosis causes a high burden of disease worldwide. This systematic review summarizes the literature on Cryptococcus neoformans and C. gattii infections to inform the World Health Organization's first Fungal Priority Pathogen List. PubMed and Web of Science were used to identify studies reporting on annual incidence, mortality, morbidity, antifungal resistance, preventability, and distribution/emergence in the past 10 years. Mortality rates due to C. neoformans were 41%-61%. Complications included acute renal impairment, raised intracranial pressure needing shunts, and blindness. There was moderate evidence of reduced susceptibility (MIC range 16-32 mg/l) of C. neoformans to fluconazole, itraconazole, ketoconazole, voriconazole, and amphotericin B. Cryptococcus gattii infections comprised 11%-33% of all cases of invasive cryptococcosis globally. The mortality rates were 10%-23% for central nervous system (CNS) and pulmonary infections, and ∼43% for bloodstream infections. Complications described included neurological sequelae (17%-27% in C. gattii infections) and immune reconstitution inflammatory syndrome. MICs were generally low for amphotericin B (MICs: 0.25-0.5 mg/l), 5-flucytosine (MIC range: 0.5-2 mg/l), itraconazole, posaconazole, and voriconazole (MIC range: 0.06-0.5 mg/l). There is a need for increased surveillance of disease phenotype and outcome, long-term disability, and drug susceptibility to inform robust estimates of disease burden.

Deciphering antifungal and antibiofilm mechanisms of isobavachalcone against Cryptococcus neoformans through RNA-seq and functional analyses

Cryptococcus neoformans has been designated as critical fungal pathogens by the World Health Organization, mainly due to limited treatment options and the prevalence of antifungal resistance. Consequently, the utilization of novel antifungal agents is crucial for the effective treatment of C. neoformans infections. This study exposed that the minimum inhibitory concentration (MIC) of isobavachalcone (IBC) against C. neoformans H99 was 8 µg/mL, and IBC dispersed 48-h mature biofilms by affecting cell viability at 16 µg/mL. The antifungal efficacy of IBC was further validated through microscopic observations using specific dyes and in vitro assays, which confirmed the disruption of cell wall/membrane integrity. RNA-Seq analysis was employed to decipher the effect of IBC on the C. neoformans H99 transcriptomic profiles. Real-time quantitative reverse transcription PCR (RT-qPCR) analysis was performed to validate the transcriptomic data and identify the differentially expressed genes. The results showed that IBC exhibited various mechanisms to impede the growth, biofilm formation, and virulence of C. neoformans H99 by modulating multiple dysregulated pathways related to cell wall/membrane, drug resistance, apoptosis, and mitochondrial homeostasis. The transcriptomic findings were corroborated by the antioxidant analyses, antifungal drug sensitivity, molecular docking, capsule, and melanin assays. In vivo antifungal activity analysis demonstrated that IBC extended the lifespan of C. neoformans-infected Caenorhabditis elegans. Overall, the current study unveiled that IBC targeted multiple pathways simultaneously to inhibit growth significantly, biofilm formation, and virulence, as well as to disperse mature biofilms of C. neoformans H99 and induce cell death.

Neurological Complications Caused by Human Immunodeficiency Virus (HIV) and Associated Opportunistic Co-infections: A Review on their Diagnosis and Therapeutic Insights

Neurocognitive disorders associated with human immunodeficiency virus (HIV) infected individuals increase the risk of mortality and morbidity that remain a prevalent clinical complication even in the antiretroviral therapy era. It is estimated that a considerable number of people in the HIV community are developing neurological complications at their early stages of infection. The daily lives of people with chronic HIV infections are greatly affected by cognitive declines such as loss of attention, learning, and executive functions, and other adverse conditions like neuronal injury and dementia. It has been found that the entry of HIV into the brain and subsequently crossing the blood-brain barrier (BBB) causes brain cell damage, which is the prerequisite for the development of neurocognitive disorders. Besides the HIV replication in the central nervous system and the adverse effects of antiretroviral therapy on the BBB, a range of opportunistic infections, including viral, bacterial, and parasitic agents, augment the neurological complications in people living with HIV (PLHIV). Given the immuno-compromised state of PLHIV, these co-infections can present a wide range of clinical syndromes with atypical manifestations that pose challenges in diagnosis and clinical management, representing a substantial burden for the public health system. Therefore, the present review narrates the neurological complications triggered by HIV and their diagnosis and treatment options. Moreover, coinfections that are known to cause neurological disorders in HIV infected individuals are highlighted.

Mapping evidence on cryptococcal antigen infection among HIV-infected persons in sub-Saharan Africa- A scoping review protocol

INTRODUCTION

Infections of the central nervous system are a considerable basis of mortality in people living with HIV, with progression to cryptococcal meningitis documented at around 15% of HIV-associated mortality globally, with nearly three-quarters occurring in the sub-Saharan Africa. Discoveries from previous studies prelude to the mortality of cryptococcal antigen positive, which persisted to be elevated than in cryptococcal antigen negative persons. One feasible interpretation of this could be due to undiagnosed cryptococcus. Laboratory investigations identify cryptococcal disease prior to cryptococcal meningitis progression. Point-of-care testing has high sensitivity and specificity as seen with the cryptococcal antigen lateral flow assay screening to expedite treatment. The aim of the study is to map and translate evidence on cryptococcal antigen infection among HIV-infected persons in sub-Saharan Africa.

METHODOLOGY

The proposed scoping review will be conducted using guidelines proposed by Arksey and O'Malley methodological framework and Levac et al. advanced method. It will be guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis for Scoping Reviews. A comprehensive literature search of studies published from the first relevant publication to 2022 will be conducted on multiple electronic databases. Additional sources (grey literature) will also be searched. The search strategy will be generated and implemented by the principal investigator with assistance from a subject specialist, and an information specialist. Two reviewers will screen eligible studies. The screening will be guided by an inclusion and exclusion criteria. The mixed methods appraisal tool version 2018 will be used to appraise the quality of the empirical studies.

DISCUSSION

The proposed scoping review will map and translate evidence on cryptococcal antigen infection among HIV-infected persons in sub-Saharan Africa. Synthesising and sharing recent evidence in this area has potential to help guide future research and interventions aimed at improving the management of cryptococcal antigen infection among HIV-infected persons in sub-Saharan Africa and other high HIV- burdened settings.

Primaquine, an antimalarial drug that controls the growth of cryptococcal cells

INTRODUCTION

The treatment of Cryptococcus neoformans with fluconazole and amphotericin B is, at times, characterised by clinical failure. Therefore, this study sought to re-purpose primaquine (PQ) as an anti-Cryptococcus compound.

METHOD

The susceptibility profile of some cryptococcal strains towards PQ was determined using EUCAST guidelines, and PQ's mode of action was examined. In the end, the ability of PQ to enhance in vitro macrophage phagocytosis was also assessed.

RESULTS

We show that PQ had a significant inhibitory effect on the metabolic activity of all tested cryptococcal strains, with 60 µM, defined as MIC₅₀ in this preliminary study, as it reduced the metabolic activity by more than 50%. Moreover, at this concentration, the drug was able to affect mitochondrial function adversely, as treated cells displayed significant (p < 0.05) loss of mitochondrial membrane potential, cytochrome c (cyt c) leakage and overproduction of reactive oxygen species (ROS) when compared to non-treated cells. It is our reasoned summation that the produced ROS targeted the cell walls and cell membranes, inducing observable ultrastructural changes and a significant (p < 0.05) increase in membrane permeability when compared to non-treated cells. Concerning the PQ effect on macrophages, it was noted that it significantly (p < 0.05) enhanced macrophage phagocytic efficiency compared to non-treated macrophages.

CONCLUSION

This preliminary study highlights the potential of PQ to inhibit the in vitro growth of cryptococcal cells. Moreover, PQ could control the proliferation of cryptococcal cells inside macrophages, which they often manipulate in a Trojan horse-like manner.

Protective interaction of human phagocytic APC subsets with Cryptococcus neoformans induces genes associated with metabolism and antigen presentation

Cryptococcal meningitis is the most common cause of meningitis among HIV/AIDS patients in sub-Saharan Africa, and worldwide causes over 223,000 cases leading to more than 181,000 annual deaths. Usually, the fungus gets inhaled into the lungs where the initial interactions occur with pulmonary phagocytes such as dendritic cells and macrophages. Following phagocytosis, the pathogen can be killed or can replicate intracellularly. Previous studies in mice showed that different subsets of these innate immune cells can either be antifungal or permissive for intracellular fungal growth. Our studies tested phagocytic antigen-presenting cell (APC) subsets from the human lung against C. neoformans. Human bronchoalveolar lavage was processed for phagocytic APCs and incubated with C. neoformans for two hours to analyze the initial interactions and fate of the fungus, living or killed. Results showed all subsets (3 macrophage and 3 dendritic cell subsets) interacted with the fungus, and both living and killed morphologies were discernable within the subsets using imaging flow cytometry. Single cell RNA-seq identified several different clusters of cells which more closely related to interactions with C. neoformans and its protective capacity against the pathogen rather than discrete cellular subsets. Differential gene expression analyses identified several changes in the innate immune cell's transcriptome as it kills the fungus including increases of TNF-α (TNF) and the switch to using fatty acid metabolism by upregulation of the gene FABP4. Also, increases of TNF-α correlated to cryptococcal interactions and uptake. Together, these analyses implicated signaling networks that regulate expression of many different genes - both metabolic and immune - as certain clusters of cells mount a protective response and kill the pathogen. Future studies will examine these genes and networks to understand the exact mechanism(s) these phagocytic APC subsets use to kill C. neoformans in order to develop immunotherapeutic strategies to combat this deadly disease.

Elevated Intracranial Pressure in Cryptococcal Meningoencephalitis: Examining Old, New, and Promising Drug Therapies

Despite the availability of effective antifungal therapy, cryptococcal meningoencephalitis (CM) remains associated with elevated mortality. The spectrum of symptoms associated with the central nervous system (CNS) cryptococcosis is directly caused by the high fungal burden in the subarachnoid space and the peri-endothelial space of the CNS vasculature, which results in intracranial hypertension (ICH). Management of intracranial pressure (ICP) through aggressive drainage of cerebrospinal fluid by lumbar puncture is associated with increased survival. Unfortunately, these procedures are invasive and require specialized skills and supplies that are not readily available in resource-limited settings that carry the highest burden of CM. The institution of pharmacologic therapies to reduce the production or increase the resorption of cerebrospinal fluid would likely improve clinical outcomes associated with ICH in patients with CM. Here, we discuss the potential role of multiple pharmacologic drug classes such as diuretics, corticosteroids, and antiepileptic agents used to decrease ICP in various neurological conditions as potential future therapies for CM.

Isolated cryptococcal osteomyelitis of the ulna in an immunocompetent patient: A case report

BACKGROUND

Cryptococcal osteomyelitis is a bone infection caused by cryptococcus. As an opportunistic infection, bone cryptococcosis usually occurs in patients with immunodeficiency diseases or in those undergoing immunosuppressive therapy and often displays characteristics of disseminated disease. Isolated cryptococcal osteomyelitis is extremely unusual in immunocompetent person. The pathogenic fungus often invades vertebrae, femur, tibia, rib, clavicle, pelvis, and humerus, but the ulna is a rare target.

CASE SUMMARY

A 79-year-old woman complaining of chronic pain, skin ulceration and a sinus on her right forearm was admitted, and soon after was diagnosed with cryptococcal osteomyelitis in the right ulna. Unexpectedly, she was also found to have apparently normal immunity. After treatment with antifungal therapy combined with surgery debridement, the patient’s osteomyelitis healed with a satisfactory outcome.

CONCLUSION

Although rare, cryptococcal osteomyelitis should be considered in the differential diagnosis of osteolytic lesions even in immunocompetent patients, and good outcomes can be expected if early definitive diagnosis and etiological treatment are established.

Proteomics of Cryptococcus neoformans: From the Lab to the Clinic

Fungal pathogens cause an array of diseases by targeting both immunocompromised and immunocompetent hosts. Fungi overcome our current arsenal of antifungals through the emergence and evolution of resistance. In particular, the human fungal pathogen, Cryptococcus neoformans is found ubiquitously within the environment and causes severe disease in immunocompromised individuals around the globe with limited treatment options available. To uncover fundamental knowledge about this fungal pathogen, as well as investigate new detection and treatment strategies, mass spectrometry-based proteomics provides a plethora of tools and applications, as well as bioinformatics platforms. In this review, we highlight proteomics approaches within the laboratory to investigate changes in the cellular proteome, secretome, and extracellular vesicles. We also explore regulation by post-translational modifications and the impact of protein-protein interactions. Further, we present the development and comprehensive assessment of murine models of cryptococcal infection, which provide valuable tools to define the dynamic relationship between the host and pathogen during disease. Finally, we explore recent quantitative proteomics studies that begin to extrapolate the findings from the bench to the clinic for improved methods of fungal detection and monitoring. Such studies support a framework for personalized medical approaches to eradicate diseases caused by C. neoformans.

Cryptococcal Meningitis and Post-Infectious Inflammatory Response Syndrome in a Patient With X-Linked Hyper IgM Syndrome: A Case Report and Review of the Literature

The hyper IgM syndromes are a rare group of primary immunodeficiency. The X-linked Hyper IgM syndrome (HIGM), due to a gene defect in CD40L, is the commonest variant; it is characterized by an increased susceptibility to a narrow spectrum of opportunistic infection. A few cases of HIGM patients with Cryptococcal meningoencephalitis (CM) have been described in the literature. Herein we report the case of a young male diagnosed in infancy with HIGM who developed CM complicated by a post-infectious inflammatory response syndrome (PIIRS), despite regular immunoglobulin replacement therapy and appropriate antimicrobial prophylaxis. The patient was admitted because of a headache and CM was diagnosed through detection of Cryptococcus neoformans in the cerebrospinal fluid. Despite the antifungal therapy resulting to negative CSF culture, the patient exhibited persistent headaches and developed diplopia. An analysis of inflammatory cytokines on CSF, as well as the brain MRI, suggested a diagnosis of PIIRS. Therefore, a prolonged corticosteroids therapy was started obtaining a complete resolution of symptoms without any relapse.

Antifungal activity of dendritic cell lysosomal proteins against Cryptococcus neoformans

Cryptococcal meningitis is a life-threatening disease among immune compromised individuals that is caused by the opportunistic fungal pathogen Cryptococcus neoformans. Previous studies have shown that the fungus is phagocytosed by dendritic cells (DCs) and trafficked to the lysosome where it is killed by both oxidative and non-oxidative mechanisms. While certain molecules from the lysosome are known to kill or inhibit the growth of C. neoformans, the lysosome is an organelle containing many different proteins and enzymes that are designed to degrade phagocytosed material. We hypothesized that multiple lysosomal components, including cysteine proteases and antimicrobial peptides, could inhibit the growth of C. neoformans. Our study identified the contents of the DC lysosome and examined the anti-cryptococcal properties of different proteins found within the lysosome. Results showed several DC lysosomal proteins affected the growth of C. neoformans in vitro. The proteins that killed or inhibited the fungus did so in a dose-dependent manner. Furthermore, the concentration of protein needed for cryptococcal inhibition was found to be non-cytotoxic to mammalian cells. These data show that many DC lysosomal proteins have antifungal activity and have potential as immune-based therapeutics.

Cryptococcal Osteomyelitis of the Entire Humerus: A Case Report

CASE

We describe a case of cryptococcal osteomyelitis in a 70-year-old man who presented with left elbow and shoulder pain. Subsequent imaging indicated osteomyelitis of the entire humerus, and he underwent debridement of the elbow and shoulder. Pathological findings revealed Cryptococcus neoformans infection. Surgical management was followed by a prolonged course of antibiotics.

CONCLUSION

Although C. neoformans is rare as the etiology of infection of the entire humerus, orthopaedic surgeons should consider cryptococcosis as a potential cause of infection.

Evaluation of a Cryptococcal Antigen Lateral Flow Assay and Cryptococcal Antigen Positivity at a Large Public Hospital in Atlanta, Georgia

BACKGROUND

Cryptococcus neoformans is a major cause of morbidity and mortality among human immunodeficiency virus (HIV)-infected persons worldwide, and there are scarce recent data on cryptococcal antigen (CrAg) positivity in the United States We sought to determine the frequency of cryptococcal disease and compare the performance of a CrAg lateral flow assay (LFA) versus latex agglutination (LA) test.

METHODS

All patients from Grady Health System in Atlanta who had a serum or cerebrospinal fluid (CSF) sample sent for CrAg testing as part of clinical care from November 2017 to July 2018 were included. Percentage positivity and test agreement were calculated.

RESULTS

Among 467 patients, 557 diagnostic tests were performed; 413 on serum and 144 on CSF. The mean age was 44 years, and most were male (69%) and had HIV (79%). Twenty-four (6.4%, 95% confidence interval [CI] = 4.1-9.4) patients were serum CrAg positive, and 8 (5.8%, 95% CI = 2.6-11.2) individuals tested positive for CSF CrAg. Although overall agreement between the LA and LFA was substantial to high for CSF (κ = 0.71, 95% CI = 0.51-0.91) and serum (κ = 0.93, 95% CI = 0.86-1.00), respectively, there were important discrepancies. Five patients had false-positive CSF LA tests that affected clinical care, and 4 patients had discordant serum tests.

CONCLUSIONS

We found a moderately high proportion of cryptococcal disease and important discrepancies between the LA test and LFA. Clinical implications of these findings include accurate detection of serum CrAg and averting unnecessary treatment of meningitis with costly medications associated with high rates of adverse events.

Interactions between fungal hyaluronic acid and host CD44 promote internalization by recruiting host autophagy proteins to forming phagosomes

Phagocytosis and autophagy play critical roles in immune defense. The human fungal pathogen Cryptococcus neoformans (Cn) subverts host autophagy-initiation complex (AIC)-related proteins, to promote its phagocytosis and intracellular parasitism of host cells. The mechanisms by which the pathogen engages host AIC-related proteins remain obscure. Here, we show that the recruitment of host AIC proteins to forming phagosomes is dependent upon the activity of CD44, a host cell surface receptor that engages fungal hyaluronic acid (HA). This interaction elevates intracellular Ca²⁺ concentrations and activates CaMKKβ and its downstream target AMPKα, which results in activation of ULK1 and the recruitment of AIC components. Moreover, we demonstrate that HA-coated beads efficiently recruit AIC components to phagosomes and CD44 interacts with AIC components. Taken together, these findings show that fungal HA plays a critical role in directing the internalization and productive intracellular membrane trafficking of a fungal pathogen of global importance.

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Fungal HA drives non-canonical and ligand-induced autophagy in phagocytic cells

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Cn recruits host CD44 to forming phagocytic cups to initiate fungal internalization

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Fungal HA-CD44 interactions elevate intracellular Ca²⁺ levels and activate CaMKKβ

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A Ca²⁺-CaMKKβ-AMPK-ULK1 signaling axis is involved in HA-CD44 induced autophagy

In vitro infection models to study fungal-host interactions

Fungal infections (mycoses) affect over a billion people per year. Approximately, two million of these infections are life-threatening, especially for patients with a compromised immune system. Fungi of the genera Aspergillus, Candida, Histoplasma and Cryptococcus are opportunistic pathogens that contribute to a substantial number of mycoses. To optimize the diagnosis and treatment of mycoses, we need to understand the complex fungal–host interplay during pathogenesis, the fungal attributes causing virulence and how the host resists infection via immunological defenses. In vitro models can be used to mimic fungal infections of various tissues and organs and the corresponding immune responses at near-physiological conditions. Furthermore, models can include fungal interactions with the host–microbiota to mimic the in vivo situation on skin and mucosal surfaces. This article reviews currently used in vitro models of fungal infections ranging from cell monolayers to microfluidic 3D organ-on-chip (OOC) platforms. We also discuss how OOC models can expand the toolbox for investigating interactions of fungi and their human hosts in the future.

Iron Assimilation during Emerging Infections Caused by Opportunistic Fungi with emphasis on Mucorales and the Development of Antifungal Resistance

Iron is a key transition metal required by most microorganisms and is prominently utilised in the transfer of electrons during metabolic reactions. The acquisition of iron is essential and becomes a crucial pathogenic event for opportunistic fungi. Iron is not readily available in the natural environment as it exists in its insoluble ferric form, i.e., in oxides and hydroxides. During infection, the host iron is bound to proteins such as transferrin, ferritin, and haemoglobin. As such, access to iron is one of the major hurdles that fungal pathogens must overcome in an immunocompromised host. Thus, these opportunistic fungi utilise three major iron acquisition systems to overcome this limiting factor for growth and proliferation. To date, numerous iron acquisition pathways have been fully characterised, with key components of these systems having major roles in virulence. Most recently, proteins involved in these pathways have been linked to the development of antifungal resistance. Here, we provide a detailed review of our current knowledge of iron acquisition in opportunistic fungi, and the role iron may have on the development of resistance to antifungals with emphasis on species of the fungal basal lineage order Mucorales, the causative agents of mucormycosis.

Cryptococcal infection in HIV-infected patients with CD4+ T-cell counts under 100/μL diagnosed in a high-income country: a multicentre cohort study

OBJECTIVES

The World Health Organization recommends routinely screening HIV-infected patients with CD4⁺ T-cell counts <100/μL for cryptococcal infection to prevent cryptococcal meningitis (CM), based on studies in Sub-Saharan Africa where the prevalence of positive cryptococcal antigen (CrAg+) is ≥ 3% in this subgroup. Data about such prevalence in Spain are unavailable and rare in other European countries. Thus, the Spanish AIDS Study Group guidelines do not recommend routinely screening. We aim to determine the prevalence and outcomes of cryptococcal infection in this subgroup of patients in Spain.

METHODS

We determined CrAg using a lateral flow assay in banked plasma from participants in the cohort of the Spanish AIDS Research Network. Eligible patients had CD4⁺ T-cell counts ≤100/μL at the time of plasma collection and a follow-up >4 weeks, unless they died.

RESULTS

We included 576 patients from June 2004 to December 2017. Of these, 43 were CrAg+ for an overall prevalence of 7.5%. There were no differences depending on birthplace. The CrAg+ was independently associated with a higher mortality at eight weeks (hazard ratio (HR) 5.36, 95% confidence interval (CI) 1.46-19.56) and 6 months (HR 3.12, 95% CI 1.19-8.21). CM was reported in 10 of the 43 CrAg+ patients. There were no cases among negatives. Five patients had CM when the plasma was collected and five developed it during the follow-up. The number of subjects needed to screen to anticipate the diagnosis of one CM case was 114.

CONCLUSIONS

The CrAg+ prevalence among HIV-infected patients with CD4⁺ T-cell counts ≤100/μL diagnosed in Spain, both immigrants and native-born Spanish, is >7%. Consequently, the Spanish AIDS Study Group guidelines have to be updated and recommend routine screening for cryptococcal infection in these patients. Future studies should explore whether this recommendation could be firmly applied to other European populations.

Opportunistic Invasive Fungal Infections Mimicking Progression of Non-Small-Cell Lung Cancer

BACKGROUND

Many studies have shown that invasive pulmonary aspergillosis, cryptococcosis, and mucormycosis can mimic radiographic and clinical features of primary lung cancer. However, more research surveying the incidence and outcomes of these fungal infections among patients with a history of lung cancer is needed. The aim of this study was to describe the occurrence and clinical outcomes of opportunistic invasive fungal infections that can mimic tumors in non-small-cell lung cancer patients.

PATIENTS AND METHODS

Patients seen at Stanford University Medical Center from January 1, 2007, to May 1, 2020, with pulmonary aspergillosis, cryptococcosis, or mucormycosis after non-small-cell lung cancer (NSCLC) diagnosis were reviewed. The European Organization for Research and Treatment of Cancer National Institute of Allergy and Infectious Diseases Mycoses Study Group criteria was used to classify patients with evidence of proven or probable invasive fungal infection within our cohort.

RESULTS

A total of 12 patients with proven or probable invasive mold infection (including 8 cases of aspergillosis) and 1 patient with proven cryptococcosis were identified, without any cases of mucormycosis. Of this cohort, 6 patients (46%) showed radiographic findings that were found to be most consistent with lung cancer by radiologists. Eight cases (62%) were suspected of cancer recurrence or progression by the treatment team on the basis of additional considerations of medical history and clinical symptoms. Most patients had active NSCLC or had a history of recurrence without active NSCLC at the time of fungal discovery (11 patients; 85%). Most patients died without full recovery (7 patients; 54%).

CONCLUSIONS

Invasive pulmonary aspergillosis and cryptococcosis can often be mistaken as cancer recurrence or progression in patients with a history of NSCLC because of mimicking radiographic and clinical characteristics.

Detected SARS-CoV-2 in Ascitic Fluid Followed by Cryptococcemia: a Case Report

SARS coronavirus-2 (SARS-CoV-2) detection in different clinical specimens has raised important insights about its pathogenesis, but some details remain to be understood. In that respect, disrupt viral control seen in solid organ transplant patients on chronic immunosuppression can help unveil pathogenic mechanisms and characterize new coronavirus disease-19 (COVID-19) immunological and clinical aspects, as well as secondary complications. We herein report a case of SARS-CoV-2 detection in ascitic fluid from a kidney transplant patient with decompensated cirrhosis and COVID-19 and then discuss about immune, cellular, and virological aspects of such clinical presentation of the disease, which also included a disseminated infection, demonstrated by viral detection in his blood sample. We subsequently discuss about the fatal outcome caused by a secondary bloodstream infection by Cryptococcus neoformans. This unprecedented case report presents ascitic fluid as a novel specimen in which SARS-CoV-2 can be detected. Immune dysregulation and cumulative risk factors may lead to secondary infections by opportunistic agents, including Cryptococcus neoformans.

Mortality After Cryptococcal Infection in the Modern Antiretroviral Therapy Era

BACKGROUND

The prevalence of cryptococcosis in people living with HIV (PLWH) in the developed world has decreased considerably in the modern antiretroviral therapy (ART) era. Although early mortality of PLWH with opportunistic infections is well understood, overall mortality has not been previously evaluated.

METHODS

We conducted a retrospective cohort study of cryptococcosis in PLWH from January 1, 2002, to July 1, 2017. Data were also evaluated before and after 2008 to evaluate the possible effect of modern ART on outcomes. Death date was obtained from the hospital's medical informatics database and the Social Security Death Index. Participants were grouped as survivors, early-mortality (death <90 days), and late-mortality (death ≥90 days) individuals.

RESULTS

We reviewed 105 PLWH with cryptococcosis, with 55 survivors (52.4%), 17 early-mortality (16.2%), and 33 late-mortality individuals (31.4%). Overall, mortality was 47.6% (n = 50) with a median follow-up of 3.7 years (interquartile range 1.1, 8.1 years). Late-mortality individuals were less likely to be virally suppressed at the last observation compared with survivors (24% vs 62%, P < 0.001). Individuals diagnosed in the modern ART era had significantly lower mortality (hazard ratio 0.5, confidence interval: 0.2 to 0.8) and were more likely to be virally suppressed at the last observation (57% vs 29%, P = 0.003). Individuals with government-provided insurance had a higher mortality compared to those with private insurance (hazard ratio 2.8, confidence interval: 1.1 to 7.2, P = 0.013).

CONCLUSIONS

Despite improvements in ART, PLWH have high mortality after cryptococcal infection that persists beyond their initial hospitalization. Lower mortality was associated with increased HIV viral suppression and private insurance in the modern ART era.

Cutaneous manifestations associated with HIV infections: A great imitator

HIV is associated with an increased incidence of mucocutaneous disorders, with the overwhelming majority of HIV-infected individuals being afflicted with skin diseases during the course of the infection. Skin diseases in HIV patients are rarely fatal, but they have a significant effect on the quality of life. The immunologic stage of the infection and the use of highly active antiretroviral therapy (HAART) are the main elements that determine the spectrum of the mucocutaneous involvement. Many skin diseases may occur simultaneously in HIV patients, and the course of these diseases may or may not be different than it is in HIV-negative individuals. The unusual, severe, and different presentations of the mucocutaneous involvement make HIV one of the great imitators in dermatology.

Longitudinal Changes in Cd4+, Cd8+ T Cell Phenotype and Activation Marker Expression Following Antiretroviral Therapy Initiation among Patients with Cryptococcal Meningitis

Despite improvement in the prognosis of HIV/AIDS (human immunodeficiency virus/acquired immune deficiency syndrome) patients on antiretroviral therapy (ART), cryptococcal meningitis (CM) still causes 10–15% mortality among HIV-infected patients. The immunological impact of ART on the CD4⁺ and CD8⁺ T cell repertoire during cryptococcal co-infection is unclear. We determined longitudinal phenotypic changes in T cell subsets among patients with CM after they initiated ART. We hypothesized that ART alters the clonotypic phenotype and structural composition of CD4⁺ and CD8⁺ T cells during CM co-infection. For this substudy, peripheral blood mononuclear cells (PBMC) were isolated at four time points from CM patients following ART initiation during the parent study (ClinicalTrials.gov number, NCT01075152). Phenotypic characterization of CD4⁺ and CD8⁺ T cells was done using T cell surface marker monoclonal antibodies by flow cytometry. There was variation in the expression of immunophenotypic markers defining central memory (CD27⁺CD45R0⁺), effector memory (CD45R0⁺CD27^–), immune activation (CD38⁺ and Human Leucocyte Antigen DR (HLA-DR⁺), and exhaustion (Programmed cell death protein one (PD-1) in the CD4⁺ T cell subset. In comparison to the CD4⁺ T cell population, the CD8⁺ central memory subset declined gradually with minimal increase in the effector memory subset. Both CD4⁺ and CD8⁺ T cell immune exhaustion and activation markers remained elevated over 12 weeks. The relative surge and decline in the expression of T cell surface markers outlines a variation in the differentiation of CD4⁺ T cells during ART treatment during CM co-infection.

HIV Initial Assessment and Routine Follow-up: What Tests to Order and Why

Laboratory tests are an important tool in the care of patients with human immunodeficiency virus. An organized approach to laboratory ordering helps clinicians to understand the utility of each test, ensure a comprehensive evaluation, and decrease use of unnecessary tests. Tests are organized around the following goals of care: confirm the diagnosis, assess for immune suppression, guide antiretroviral therapy, screen for coinfections and latent infections, monitor response to therapy, and provide preventative care. This article reviews appropriate testing for patients with human immunodeficiency virus to accomplish these goals with a focus on how each test is useful in clinical practice.

Disseminated cryptococcal infection in a patient with treatment-naïve chronic lymphocytic leukemia (CLL)

We report a case of disseminated cryptococcosis in a treatment-naïve chronic lymphocytic leukemia (CLL) patient. A 60-year-old man presented with a two-week history of intermittent fevers, frontal headaches, night sweats, weight loss and multiple pink papules on hands and face. Cryptococcemia was found by blood culture unexpectedly. Further investigation confirmed cryptococcal meningitis and skin disease. He responded to two week amphotericin B and flucytosine followed by four-week amphotericin B and fluconazole, three-month high dose fluconazole (800 mg/day), and maintenance fluconazole (400 mg/day) thereafter. CSF pleocytosis persisted until day 203 while cryptococcal antigen in the CSF persisted at day 334 of treatment.

Anti-infective Properties of the Golden Spice Curcumin

The search for novel anti-infectives is one of the most important challenges in natural product research, as diseases caused by bacteria, viruses, and fungi are influencing the human society all over the world. Natural compounds are a continuing source of novel anti-infectives. Accordingly, curcumin, has been used for centuries in Asian traditional medicine to treat various disorders. Numerous studies have shown that curcumin possesses a wide spectrum of biological and pharmacological properties, acting, for example, as anti-inflammatory, anti-angiogenic and anti-neoplastic, while no toxicity is associated with the compound. Recently, curcumin’s antiviral and antibacterial activity was investigated, and it was shown to act against various important human pathogens like the influenza virus, hepatitis C virus, HIV and strains of Staphylococcus, Streptococcus, and Pseudomonas. Despite the potency, curcumin has not yet been approved as a therapeutic antiviral agent. This review summarizes the current knowledge and future perspectives of the antiviral, antibacterial, and antifungal effects of curcumin.

Magnitude of Cryptococcal Antigenemia among HIV Infected Patients at a Referral Hospital, Northwest Ethiopia

Background

Cryptococcosis is one of the common opportunistic fungal infections among HIV infected patients living in Sub-Saharan Africa, including Ethiopia. The magnitude of the disease at Felege Hiwot Referral Hospital (FHRH) in particular and in Ethiopia at large is not well explored.

Methods

A retrospective document review and analysis was done on records of 137 HIV infected patients who visited FHRH ART clinic from 1 Sep to 30 Dec 2016 and had registered data on their sex, age, CD4 count and cryptococcal antigen screening result. The cryptoccocal antigen (CrAg) detection was done by the IMMY CrAg^® LFA (Cryptococcal Antigen Lateral Flow Assay) kit from patient serum as per the manufacturer's instruction. All data were entered, cleared, and analyzed using SPSS v20. Descriptive data analysis and cross tabulation were done to assess factors associated with cryptococcal antigenemia. Statistical significance was set at p-value less than or equal to 0.05.

Results

More than half of the participants, 54.7% (75/137), included in the study were females. The median age of the participants was 32.0 years (ranged: 8–52 years). The mean CD4 count was 51.8 with SD of 26.3 (range 3–98). All the patients were HIV stage IV. The proportion of positive cryptococal antigen from serum test was at 11.7% (95% CI: 7.3–18.1%). The IMMY CrAg^® LFA result was found statically associated with patient sex (p= 0.045). However, it was not associated with patient age group and the CD4 count (P>0.05)

Conclusions

This study provided baseline data on the magnitude of cryptococcal antigenemia among HIV positive patients that is not touched before in the studied area. The results of the study showed that this opportunistic fungal infection is an important health concern among HIV patients. Further studies with sound design employing adequate sample size should be considered.

Fluconazole resistance is not a predictor of poor outcome in patients with cryptococcosis

BACKGROUND

Cryptococcus isolates with high MICs to fluconazole are increasingly reported, and a potential clinical impact has been advocated. However, there are different methods to evaluate fluconazole MICs and comparative analysis among such techniques and their comprehensive correlation with clinical outcome are not available.

METHODS

Over a 13-year period (2000-2013), fluconazole MICs were determined for 62 cryptococcal isolates recovered from 22 patients with cryptococcosis using CLSI M27-A3, EUCAST, E test and Sensititre YeastOne, simultaneously. The relationship between the fluconazole MICs and the clinical outcome at week 10 was assessed in patients who received fluconazole as induction or maintenance therapy (n = 16).

RESULTS

The percentage of cryptococcal strains with MIC values ≥16 μg/mL according to different methods was CLSI 1.6%, EUCAST 16.1%, E test 31.6% and Sensititre YeastOne 53.2%. Among the 16 patients treated with fluconazole, no correlation between clinical outcome and any MIC value obtained with either method was observed. The only variable independently associated with a poor outcome was having a disseminated disease.

CONCLUSIONS

There is a weak correlation between fluconazole MICs against Cryptococcus spp. as determined by CLSI, EUCAST, E test and Sensititre YeastOne. Neither procedure could predict the clinical outcome of patients with cryptococcosis receiving fluconazole-based therapy. With present methods, fluconazole resistance in Cryptococcus may be clinically misleading.

Recent progress in the strategic incorporation of fluorine into medicinally active compounds

This account exemplifies our recent progress on the strategic incorporation of fluorine and organofluorine groups to (i) taxoid anticancer agents, (ii) acylhydrazone-based antifungal agents and (iii) inhibitors of matrix metalloproteinase 9 (MMP9) for medicinal chemistry and chemical biology studies. In the case study (i), a series of next-generation fluorotaxoids, bearing m-OCF3 or m-OCF2H group in the C2-benzoate moiety was designed, synthesized and examined for their potencies. A number of these fluorotaxoids possess two orders of magnitude greater potency in different drug-resistant cancer cell lines as compared to paclitaxel. One of these next-generation fluorotaxoids, SB--121205wasselected for detailed mechanistic study against highly paclitaxel-resistant human breast cancer cell line, MCF-7/PTX, which disclosed a unique mechanism of action. Recently, glucosylceramide (GlcCer) synthesis emerged as a promising target for next-generation antifungal agents, especially against cryptococcosis, candidiasis and pulmonary aspergillosis. The HTP screening of compound libraries identified several acylhydrazones as hit compounds. In the case study (ii), fluoro-acylhydrazones containing F, OCF3, OCHF2, o-F/p-OCF3, as well as o-F/p-CF3 functional groups in the ring A and ring B were designed based on these hit compounds, synthesized and examined for their potencies against C. neoformans. A number of those novel fluoro-acylhydrazones exhibited high potency and excellent killing properties. The hemopexin-like domain of matrix metalloproteinases (MMPs) is a highly promising target to circumvent the critical issue in the development of MMP inhibitors for the treatment of various cancers. In the case study (iii), a small optimization library of compounds, based on the OCHF2-containing hit compound, SB-M-001, was generated and evaluated, which identified a fluorine-containing new lead compound, SB-M-103. SB-M-103 was found to inhibit tumor cell growth, migration, and invasion by effectively disrupting the MMP-9 homodimerization.

Rare presentation of cutaneous cryptococcosis in advanced HIV

Cryptococcus neoformans is an encapsulated yeast which causes opportunistic infection in the context of immunosuppression, including advanced HIV infection. Cryptococcal infection is systemic and can result in a fatal meningoencephalitis. Cutaneous lesions occur in 15% of those with systemic cryptococcosis and may be the first indicator of infection. Identification of these lesions may therefore expedite diagnosis and access to treatment. Cutaneous lesions typically present as papulonodular molluscum-like lesions; however, may vary significantly in appearance. We describe a rare case of extraneuronal cryptococcal infection manifesting as large subcutaneous tumours in a patient with advanced HIV-related immune deficiency.

Looking for fungi in all the right places: screening for cryptococcal disease and other AIDS-related mycoses among patients with advanced HIV disease

PURPOSE OF REVIEW

As HIV treatment programmes scale up to meet the UNAIDS 90-90-90 goals, care must be taken to start antiretroviral treatment safely in patients with advanced disease (CD4 counts <200 cells/μl) who are simultaneously at risk for opportunistic infections and immune reconstitution inflammatory syndrome. Invasive fungal diseases pose a great threat at this critical time point, though the development of inexpensive and highly accurate rapid diagnostic tests has changed the approach HIV programmes are taking to reduce the high mortality associated with these opportunistic infections. This article summarizes recent advances and findings in fungal opportunistic infection diagnostics with a focus on screening to prevent cryptococcal meningitis.

RECENT FINDINGS

Cryptococcal antigen (CrAg) screening using a lateral flow assay platform is cost-effective and feasible to implement as either a laboratory reflex or point-of-care test. Recent CrAg screening pilots have elucidated the varying prevalence of cryptococcal antigenemia across geographic regions, which may aid programme planning. Evidence from recently completed clinical trials provides a strong motivation for the use of CrAg titer to refine treatment options for patients with subclinical cryptococcal disease.

SUMMARY

Although several operational barriers to programme effectiveness still need to be addressed, the utility of CrAg screening using inexpensive and accurate antigen assays has been demonstrated in real-world HIV programmes, paving the way for development and testing of other fungal opportunistic infection screening strategies and for an integrated advanced HIV disease testing package to reduce AIDS mortality and ensure safe antiretroviral treatment initiation.

Prevalence of cryptococcal infection among advanced HIV patients in Argentina using lateral flow immunoassay

BACKGROUND

Globally, Latin America ranks third among regions with most cases of AIDS related cryptococcal meningitis. In 2009, a lateral flow immunoassay (LFA) for the detection of cryptococcal antigen (CrAg) was developed as a potential point-of-care test for diagnosis of cryptococcal infection. In 2011 World Health Organizations recommended on CrAg screening for HIV positive persons with CD4 below 100 cells/μL, followed by preemptive fluconazole treatment. However, in Argentina no formal recommendations for CrAg screening have been issued.

METHODS

HIV positive patients > = 18 years with advanced immunosuppression (CD4 counts ≤100 cells/μL within 3 months or WHO stage III/IV), who visited the hospital between April 1, 2014 and January 31, 2015, were included. The LFA was performed according to the manufacturer's instructions on all serum samples. When CrAg detection was positive, a lumbar puncture was performed to rule out cryptococcal meningitis. Patients without evidence of meningeal involvement were treated with preemptive oral fluconazole in ambulatory care.

RESULTS

We included 123 patients. Prevalence of CrAg-positivity was 8.1%. Among the 10 CrAg-positive patients, 6 had meningeal involvement detected through the CSF analysis (CSF India-ink testing, CSF CrAg and culture). The remaining 4 patients with positive CrAg received targeted preemptive treatment with oral fluconazole and were free of cryptococcal disease during the follow-up period. None of the 113 patients with a negative CrAg test result developed cryptococcal disease.

CONCLUSIONS

This is the first study in Argentina, to our knowledge, describing the prevalence of cryptococcosis and usefulness of CrAg screening. LFA provided early diagnosis to determine a high prevalence of CrAg in our hospital, and that screening for subclinical infection with preemptive antifungal treatment, prevented a substantial proportion of meningeal disease.

Cysteinyl leukotrienes as novel host factors facilitating Cryptococcus neoformans penetration into the brain

Cryptococcus neoformas infection of the central nervous system (CNS) continues to be an important cause of mortality and morbidity, and a major contributing factor is our incomplete knowledge of the pathogenesis of this disease. Here, we provide the first direct evidence that C. neoformans exploits host cysteinyl leukotrienes (LTs), formed via LT biosynthetic pathways involving cytosolic phospholipase A₂ α (cPLA₂ α) and 5-lipoxygenase (5-LO) and acting via cysteinyl leukotriene type 1 receptor (CysLT1), for penetration of the blood-brain barrier. Gene deletion of cPLA₂ α and 5-LO and pharmacological inhibition of cPLA₂ α, 5-LO and CysLT1 were effective in preventing C. neoformans penetration of the blood-brain barrier in vitro and in vivo. A CysLT1 antagonist enhanced the efficacy of an anti-fungal agent in therapy of C. neoformans CNS infection in mice. These findings demonstrate that host cysteinyl LTs, dependent on the actions of cPLA₂ α and 5-LO, promote C. neoformans penetration of the blood-brain barrier and represent novel targets for elucidating the pathogenesis and therapeutic development of C. neoformans CNS infection.

Novel cell-based in vitro screen to identify small-molecule inhibitors against intracellular replication of Cryptococcus neoformans in macrophages

The fungal pathogen Cryptococcus neoformans poses a major threat to immunocompromised patients and is a leading killer of human immunodeficiency virus (HIV)-infected patients worldwide. Cryptococci are known to manipulate host macrophages and can either remain latent or proliferate intracellularly within the host phagocyte, a favourable niche that also renders them relatively insensitive to antifungal agents. Here we report an attempt to address this limitation by using a fluorescence-based drug screening method to identify potential inhibitors of intracellular proliferation of C. neoformans. The Prestwick Chemical Library(®) of FDA-approved small molecules was screened for compounds that limit the intracellular replication of a fluorescently-tagged C. neoformans reference strain (H99-GFP) in macrophages. Preliminary screening revealed 19 of 1200 compounds that could significantly reduce intracellular growth of the pathogen. Secondary screening and host cell cytotoxicity assays highlighted fendiline hydrochloride as a potential drug candidate for the development of future anticryptococcal therapies. Live cell imaging demonstrated that this Ca(2+) channel blocker strongly enhanced phagosome maturation in macrophages leading to improved fungal killing and reduced intracellular replication. Whilst the relatively high dose of fendiline hydrochloride required renders it unfit for clinical deployment against cryptococcosis, this study highlights a novel approach for identifying new lead compounds and unravels a pharmacologically promising scaffold towards the development of novel antifungal therapies for this neglected disease.

Deep Fungal Infections, Blastomycosis-Like Pyoderma, and Granulomatous Sexually Transmitted Infections

Granulomatous diseases are caused by multiple infectious and noninfectious causes. Deep fungal infections can present in the skin or extracutaneously, most commonly with lung manifestations. An Azole or amphotericin B is the universal treatment. Blastomycosis-like pyoderma is a clinically similar condition, which is caused by a combination of hypersensitivity and immunosuppression. Successful treatment has been reported with antibiotics and, more recently, the vitamin A analog, acitretin. Granuloma inguinale and lymphogranuloma venereum cause ulcerative genital lesions with a granulomatous appearance on histology. The Centers for Disease Control and Prevention recommens treatment of these genital infections with doxycycline.

Diabetes mellitus is associated with acquisition and increased mortality in HIV-uninfected patients with cryptococcosis: A population-based study

OBJECTIVES

To disclose the association between diabetes mellitus (DM) and cryptococcosis in HIV-uninfected patients.

METHODS

Case patients' diagnoses with cryptococcosis and cryptococcal meningitis were based on data from the Taiwan National Health Insurance Research Database from 2000 to 2010, and diagnoses were defined using the International Classification of Disease, Ninth Revision, Clinical Modification. A case-control study comprising inpatient and outpatient populations was conducted using 4 controls for each patient (4587 case patients and 18,348 controls) matched for age, sex, monthly income, and urbanization level.

RESULTS

Human immunodeficiency virus (HIV)-uninfected patients with cryptococcosis were more likely to have diabetes than matched control patients (adjusted odds ratio [OR], 1.45; 95% confidence interval [95% CI], 1.36-1.64; p < 0.001). A diagnosis of DM was also associated with 1-year and overall mortality from cryptococcosis (hazard ratio [HR], 1.39; 95% CI, 1.17-1.65; p < 0.001, HR, 1.47; 95% CI, 1.29-1.67; p < 0.001; respectively) and cryptococcal meningitis (p = 0.018).

CONCLUSIONS

Diabetes was associated with the occurrence of cryptococcosis and cryptococcal meningitis in HIV-uninfected patients. DM was also associated with 1-year and overall mortality for these patients.

Simvastatin inhibits planktonic cells and biofilms of Candida and Cryptococcus species

The antifungal activity of some statins against different fungal species has been reported. Thus, at the first moment, the in vitro antifungal activity of simvastatin, atorvastatin and pravastatin was tested against Candida spp. and Cryptococcus spp. Then, in a second approach, considering that the best results were obtained for simvastatin, this drug was evaluated in combination with antifungal drugs against planktonic growth and tested against biofilms of Candida spp. and Cryptococcus spp. Drug susceptibility testing was performed using the microdilution broth method, as described by the Clinical and Laboratory Standards Institute. The interaction between simvastatin and antifungals against planktonic cells was analyzed by calculating the fractional inhibitory concentration index. Regarding biofilm susceptibility, simvastatin was tested against growing biofilm and mature biofilm of one strain of each tested yeast species. Simvastatin showed inhibitory effect against Candida spp. and Cryptococcus spp. with minimum inhibitory concentration values ranging from 15.6 to 1000 mg L⁻¹ and from 62.5 to 1000 mg L⁻¹, respectively. The combination of simvastatin with itraconazole and fluconazole showed synergism against Candida spp. and Cryptococcus spp., while the combination of simvastatin with amphotericin B was synergistic only against Cryptococcus spp. Concerning the biofilm assays, simvastatin was able to inhibit both growing biofilm and mature biofilm of Candida spp. and Cryptococcus spp. The present study showed that simvastatin inhibits planktonic cells and biofilms of Candida and Cryptococcus species.

Prevalence, correlates, and outcomes of cryptococcal antigen positivity among patients with AIDS, United States, 1986-2012

BACKGROUND

Cryptococcal meningitis (CM) is one of the most common causes of AIDS-related mortality worldwide, accounting for 33%-63% of all cases of adult meningitis in sub-Saharan Africa and >500 000 deaths annually. In sub-Saharan Africa, the World Health Organization recommends routinely screening AIDS patients with a CD4 count ≤100 cells/µL for cryptococcal infection. In the United States, there are no recommendations for routine screening. We aimed to determine the prevalence of cryptococcal infection and outcomes of those infected among people living with advanced AIDS in the United States, to inform updates in the prevention and management of CM.

METHODS

Using stored sera from participants in the Multicenter AIDS Cohort Study and the Women's Interagency HIV Study from 1986 to 2012, we screened 1872 specimens with CD4 T-cell counts ≤100 cells/µL for cryptococcal antigen (CrAg) using the CrAg lateral flow assay.

RESULTS

The overall prevalence of CrAg positivity within the study population was 2.9% (95% confidence interval, .2%-3.8%). Results from multivariable analysis revealed that a previous diagnosis with CM and a CD4 count ≤50 cells/µL were significantly associated with CrAg positivity. Participants who were CrAg positive had significantly shorter survival (2.8 years) than those who were CrAg negative (3.8 years; P = .03).

CONCLUSIONS

The prevalence of cryptococcal infection among advanced AIDS patients in the United States was high and above the published cost-effectiveness threshold for routine screening. We recommend routine CrAg screening among human immunodeficiency virus-infected patients with a CD4 count ≤100 cells/µL to detect and treat early infection.

Recognition of seven species in the Cryptococcus gattii/Cryptococcus neoformans species complex

Phylogenetic analysis of 11 genetic loci and results from many genotyping studies revealed significant genetic diversity with the pathogenic Cryptococcus gattii/Cryptococcus neoformans species complex. Genealogical concordance, coalescence-based, and species tree approaches supported the presence of distinct and concordant lineages within the complex. Consequently, we propose to recognize the current C. neoformans var. grubii and C. neoformans var. neoformans as separate species, and five species within C. gattii. The type strain of C. neoformans CBS132 represents a serotype AD hybrid and is replaced. The newly delimited species differ in aspects of pathogenicity, prevalence for patient groups, as well as biochemical and physiological aspects, such as susceptibility to antifungals. MALDI-TOF mass spectrometry readily distinguishes the newly recognized species.

Extensive Central Nervous System Cryptococcal Disease Presenting as Immune Reconstitution Syndrome in a Patient with Advanced HIV: Report of a Case and Review of Management Dilemmas and Strategies

One of the complications of the use of antiretroviral therapy (ART), immune reconstitution inflammatory syndrome (IRIS), is particularly problematic in the management of cryptococcal meningitis. We present the case of a 35-year-old male with acquired immune deficiency syndrome diagnosed with extensive central nervous system (CNS) cryptococcal disease, including meningitis and multiple intracranial cysts, diagnosed eight weeks after the initiation of ART. The patient experienced a relapsing and remitting clinical course despite repeated courses of potent antifungal therapy and aggressive management of raised intracranial pressure. This review highlights therapeutic dilemmas and strategies in the management of CNS cryptococcosis complicated with IRIS and highlights gaps in available treatment guidelines.

Immunoreactivity of synthetic peptides derived from proteins of Cryptococcus gattii

AIM

To determine the immunoreactivity of synthetic Cryptococcus-derived peptides.

MATERIALS & METHODS

A total of 63 B-cell epitopes from previously identified Cryptococcus gattii immunoreactive proteins were synthesized and evaluated as antigens in ELISAs. The peptides were first evaluated for their ability to react against sera from immunocompetent subjects carrying cryptococcal meningitis. Peptides that yielded high sensitivity and specificity in the first test were then retested with sera from individuals with other fungal pathologies for cross-reactivity determination.

RESULTS

Six of 63 synthetic peptides were recognized by antibodies in immunoassays, with a specificity of 100%, sensitivity of 78% and low cross-reactivity.

CONCLUSION

We successfully determined the immunoreactivity of selected synthetic peptides of C. gattii derived proteins.

Clinical characteristics and outcomes in 303 HIV-infected patients with invasive fungal infections: data from the Prospective Antifungal Therapy Alliance registry, a multicenter, observational study

This analysis aimed to characterize the epidemiology, diagnosis, treatment, and outcomes of invasive fungal infections (IFIs) in patients with human immunodeficiency virus (HIV). Data were examined for HIV patients enrolled in the Prospective Antifungal Therapy (PATH) Alliance registry, a multicenter, observational study of patients with IFIs in North America from 2004 to 2008. Patient demographics, clinical characteristics, comorbidities, antifungal therapies, and survival were assessed. In total, 320 fungal isolates were identified from 303 HIV patients with IFIs in the PATH Alliance® registry. These included Cryptococcus (50.0%), Candida (33.1%), Histoplasma (9.1%), and Aspergillus (4.4%). Candida infection occurred mainly as candidemia (86.0%); Cryptococcus as central nervous system infection (76.7%); Histoplasma as disseminated infection (74.1%); and Aspergillus as pulmonary infection (81.8%). The CD4 cell count was ≤200 cells/μL in 91.2% of patients with available data. The majority of patients with Cryptococcus (77.9%), Histoplasma (100.0%), and Aspergillus (71.4%) infections had CD4 cell counts <50 cells/μL compared with 48.9% of patients with Candida infections. Patients with candidiasis were more likely to have other conditions requiring medical services compared with patients with other IFIs. Survival probability was lower in patients with Aspergillus (0.58) and Candida (0.59) infection than in patients with Histoplasma (0.84) and Cryptococcus (0.81) infection. In the highly active antiretroviral therapy era, traditional opportunistic IFIs such as cryptococcosis and histoplasmosis still mainly occur in HIV patients with CD4 counts <50 cells/μL. Fungal infections remain a clinical challenge in HIV patients with severe immunosuppression. Our data also suggest that HIV patients with CD4 cell counts >200 cells/μL and other underlying conditions may be susceptible to invasive candidiasis.

Molecular epidemiology and antifungal susceptibility of Serbian Cryptococcus neoformans isolates

Molecular typing and antifungal susceptibility testing of 34 clinical Serbian Cryptococcus neoformans isolates from 25 patients was retrospectively performed. Amplified fragment length polymorphism (AFLP) fingerprinting was used for genotyping, whereas a novel real-time PCR was used to determine the mating- and serotype. The antifungals amphotericin B, 5-fluorocytosine, fluconazole, voriconazole, itraconazole and posaconazole were used to determine the antifungal susceptibility profiles. The majority of isolates belonged to genotype AFLP1/VNI (n = 20; 58.8%), followed by AFLP2/VNIV (n = 10; 29.4%), AFLP3/VNIII (n = 3; 8.8%) and AFLP1B/VNII (n = 1; 2.9%). All AFLP1/VNI isolates were mating-serotype αA, the sole AFLP1B/VNII isolate was found to be aA, whereas AFLP2/VNIV harboured serotype D isolates with either the a (n = 2; 5.9%) or α (n = 8; 23.5%) mating-type allele. The isolates (n = 3; 8.8%) that were found to be genotype AFLP3/VNIII had the hybrid mating- and serotype combination aA-αD. In vitro antifungal susceptibility testing showed that all isolates were susceptible to amphotericin B, voriconazole and posaconazole. Low resistance level was observed for fluconazole (n = 1; 2.9%) and 5-fluorocytosine. (n = 2; 5.8%). A large percentage of isolates was found to be susceptible dose dependent to itraconazole (n = 16; 47.1%). AFLP1/VNI was the most common genotype among clinical C. neoformans isolates from immunocompromised patients in Serbia. C. neoformans from HIV-negative patients were significantly less susceptible to 5-fluorocytosine (P < 0.01). Correlation between genotypes and antifungal susceptibility was not observed.

Approaches to antifungal therapies and their effectiveness among patients with cryptococcosis

The goal of this study was to determine the degree to which the persistence of cryptococcosis, overall 1-year mortality, and 1-year mortality due to cryptococcosis were influenced by initial antifungal treatment regimen in a cohort of adults with cryptococcosis treated at a tertiary care medical center. Risk factors, underlying conditions, treatment, and mortality information were obtained for 204 adults with cryptococcosis from Duke University Medical Center (DUMC) from 1996 to 2009. Adjusted risk ratios (RR) for persistence and hazard ratios (HR) for mortality were estimated for each exposure. The all-cause mortality rate among patients with nonsevere disease (20%) was similar to that in the group with disease (26%). However, the rate of cryptococcosis-attributable mortality with nonsevere disease (5%) was much lower than with severe disease (20%). Flucytosine exposure was associated with a lower overall mortality rate (HR, 0.4; 95% confidence interval [CI], 0.2 to 0.9) and attributable mortality rate (HR, 0.5; 95% CI, 0.2 to 1.2). Receiving a nonrecommended antifungal regimen was associated with a higher relative risk of persistent infection at 4 weeks (RR, 1.9; 95% CI, 0.9 to 4.3), and the rate of attributable mortality among those not receiving the recommended dose of initial therapy was higher than that of those receiving recommended dosing (HR, 2.3; 95% CI, 1.0 to 5.0). Thus, the 2010 Infectious Diseases Society of America (IDSA) guidelines are supported by this retrospective review as a best-practice protocol for cryptococcal management. Future investigations should consider highlighting the distinction between all-cause mortality and attributable mortality so as not to overestimate the true effect of cryptococcosis on patient death.

The Mannoprotein Cig1 supports iron acquisition from heme and virulence in the pathogenic fungus Cryptococcus neoformans

Iron acquisition is critical for virulence of the human pathogenic fungus Cryptococcus neoformans. The cryptococcal transcript for the extracellular mannoprotein Cig1 is highly regulated by iron and abundant in iron-starved cells, suggesting a role in iron acquisition. Indeed, loss of Cig1 resulted in delayed growth on heme at physiological pH. Expression of CIG1 is regulated by the pH-responsive transcription factor Rim101, and loss of Rim101 also impaired growth on heme. A cig1Δ mutant was less susceptible than the wild-type strain to noniron metalloporphyrins, further indicating a role for Cig1 in heme uptake. Recombinant Cig1 exhibited the absorbance spectrum of a heme-binding protein upon heme titration, and Cig1 may therefore function as a hemophore at the cell surface. Cig1 contributed to virulence in a mouse model of cryptococcosis but only in a mutant that also lacked the high-affinity iron uptake system. Overall, Cig1-mediated heme uptake is a potential therapeutic target in C. neoformans.