Cryptococcosis

Lung adenocarcinoma concurrent with pulmonary cryptococcosis: a case report and literature review

Pulmonary cryptococcosis (PC) is a common opportunistic fungal infection caused by Cryptococcus neoformans or Cryptococcus gattii. PC primarily invades the respiratory system, followed by the central nervous system. Few clinical reports have examined the coexistence of PC and lung cancer. This study reports the case of a 54-year-old immunocompetent PC patient with lung adenocarcinoma. Chest CT revealed multiple nodules in the right lung, with the largest nodule located in the dorsal segment of the right lower lobe. 18 F‑FDG positron emission tomography-computed tomography (PET-CT) revealed elevated glucose metabolism in the dorsal segment of the right lower lobe, which suggested lung cancer. The metabolism level of the nodule in the basal segment of the right lower lobe and the anterior segment of the right upper lobe was not abnormally increased, but the possibility of a malignant tumour could not be excluded. The pulmonary nodules in the dorsal segment and the basal segment of the right lower lobe were simultaneously resected via video-assisted thoracic surgery (VATS), and the final histopathology revealed primary lung adenocarcinoma and pulmonary cryptococcal infection, respectively. After surgery, antifungal treatment was administered for 3 months. Over the 3-year follow-up, contrast-enhanced computed tomography (CT) revealed no recurrence of either disease. This case study highlights the possibility of dualism in the diagnosis of multiple pulmonary nodules on chest CT, such as the coexistence of lung cancer and PC. Surgical resection is recommended for micronodules that are not easy to diagnose via needle biopsy; in addition, early diagnosis and treatment are helpful for ensuring a good prognosis. This paper reports the clinical diagnosis and treatment of one patient with pulmonary cryptococcal infection of the right lung complicated with lung adenocarcinoma, including 3 years of follow-up, providing a reference for clinical practice.

Synergistic antifungal activity against Candida albicans between voriconazole and cyclosporine a loaded in polymeric nanoparticles

The goal of this work is to investigate if the synergistic antifungal activity between cyclosporine A, CsA, and voriconazole, VRZ, increases when both drugs are encapsulated in a nanocarrier as compared when they are free. The preparation and characterization of blank and VRZ and CsA loaded polymeric based PLGA nanoparticles (PLGA, PLGA-PEG, and PLGA+PEG) was a necessary previous step. Using the more suitable NPs, those of PLGA, the antifungal susceptibility tests performed with VRZ-loaded PLGA NPs, show no significant increase of the antifungal activity in comparison to that of free VRZ. However, the synergistic behavior found for the (VRZ+CsA)-loaded PLGA NPs was fourfold stronger than that observed for the two free drugs together. On the other hand, the investigation into the suppression of C. albicans biofilm formation showed that blank PLGA NPs inhibit the biofilm formation at high NPs concentrations. However, a minor effect or even a slight biofilm increase formation was observed at low and moderate NPs concentrations. Therefore, the enhancement of the biofilm inhibition found for the three tested treatments (CsA alone, VRZ alone, and VRZ+CsA) when comparing free and encapsulated drugs, within the therapeutic window, can be attributed to the drug encapsulation approach. Indeed, polymeric PLGA NPs loaded with CsA, VRZ, or VRZ+CsA are more effective at inhibiting the C. albicans biofilm growth than their free counterparts.

Clinical and immunological features of laryngeal cryptococcosis

The literature holds few descriptions on immune response findings for laryngeal cryptococcosis. Immunology has been more extensively described in cases involving the central nervous system and the lungs, although many of these studies were conducted in animal models. We aimed to analyze the clinical and immunological characteristics of three patients with laryngeal cryptococcosis. We observed a weak participation of the innate immune response, whereas adaptive immunity showed the predominance of a Th2-type response over a Th1-type response. Most cases occur in male older adults with immunosuppressive conditions, of which HIV infection was absent. Hoarseness configured the main symptom. We found a disease that was restricted to the larynx and possibly the lungs by contiguity. Patients with hoarseness and lesions in nasal endoscopy should be investigated for cryptococcosis by a biopsy of the larynx, including with negative serum cryptococcal antigen. The immunological aspects of our findings of laryngeal involvement resembled those in the most commonly affected systems.

Antifungal resistance: why are we losing this battle?

The emergence of fungal pathogens and changes in the epidemiological landscape are prevalent issues in clinical mycology. Reports of resistance to antifungals have been reported. This review aims to evaluate molecular and nonmolecular mechanisms related to antifungal resistance. Mutations in the ERG genes and overexpression of the efflux pump (MDR1, CDR1 and CDR2 genes) were the most reported molecular mechanisms of resistance in clinical isolates, mainly related to Azoles. For echinocandins, a molecular mechanism described was mutation in the FSK genes. Furthermore, nonmolecular virulence factors contributed to therapeutic failure, such as biofilm formation and selective pressure due to previous exposure to antifungals. Thus, there are many public health challenges in treating fungal infections.

The role of veterinarians in zoonosis prevention: Advising families of immunocompromised children with pets

Background

Pet ownership is widespread, offering numerous benefits to individuals and families. However, the risk of zoonotic diseases must be carefully considered, especially for immunosuppressed patients. Knowledge gaps in preventive measures for zoonoses have been identified, underscoring the vital role of veterinarians in addressing this issue.

Objectives

This study aimed to assess the knowledge and recommendations of veterinarians regarding pet ownership by immunocompromised individuals. Additionally, we compared these insights with responses from European healthcare professionals specializing in pediatric transplant recipients.

Methods

We conducted an observational, cross-sectional study involving small animal veterinarians in Spain. An online survey was administered to gather information on veterinarians' knowledge of zoonoses and their recommendations for immunocompromised pet owners.

Results

A survey of 514 individuals was collected from experienced veterinarians mainly working in primary care clinics. Surprisingly, 63% of respondents did not routinely inquire about the presence of immunocompromised individuals among pet owners, although 54% offered specific recommendations for this group. Most respondents adhered to deworming guidelines for pets owned by immunocompromised individuals and demonstrated sound practices in Leishmania and Leptospira prevention, as well as the avoidance of raw food. However, gaps were noted concerning Bordetella bronchiseptica vaccination. Notably, veterinarians outperformed medical professionals in their knowledge of zoonotic cases and identification of zoonotic microorganisms. The presence of specific recommendations in veterinary clinics was viewed positively by nearly all respondents.

Conclusions

Our findings indicate that veterinarians possess a superior understanding of zoonotic pathogens and exhibit greater proficiency in diagnosing zoonoses compared with physicians. They stay well-informed about recommendations outlined in established guidelines and are more likely to provide written recommendations in their clinics than physicians. Nevertheless, knowledge gaps among veterinarians emphasize the need for enhanced communication between medical and veterinary professionals. Reinforcing the "One Health" concept is imperative, with veterinarians playing a pivotal role in this collaborative effort.

A sandwich chemiluminescent magnetic microparticle immunoassay for cryptococcal antigen detection

BACKGROUND

Cryptococcosis is a global invasive mycosis associated with significant morbidity and mortality. Cryptococcal antigen (CrAg) testing from serum and cerebrospinal fluid (CSF) has been regarded as a gold standard for early diagnosis. This study aimed to develop and validate a rapid and sensitive sandwich chemiluminescent magnetic microparticle immunoassay (CMIA) for quantitative detection of CrAg in sera.

RESEARCH DESIGN AND METHODS

CMIA is based on magnetic beads modified with capture antibodies and biotinylated antibodies and Streptavidin-polyHRP, where biotinylated antibodies functioned as the recognition element and Streptavidin-polyHRP as the signal component. Assay parameters were first optimized, and then assay performances were evaluated.

RESULTS

Under optimized conditions, the total runtime of the CMIA was 22 min. The assay had a wide linear range (2 -10,000 ng/mL) and high analytical sensitivity (0.24 ng/mL), together with acceptable reproducibility, accuracy, and stability. Besides, it exhibited no cross-reactivity with other pathogens. Importantly, the assay showed 92.91% (95% CI, 80.97-93.02%) overall qualitative agreement with a commercial ELISA kit in a retrospective cohort of 55 cases with confirmed cryptococcal infection, and 72 controls without evidence of invasive fungal disease (IFD).

CONCLUSION

These results demonstrated that the present study paved a novel strategy for reliable quantitative detection of CrAg in sera.

Outcomes and factors associated with cryptococcal disease among cirrhotics: A study of the national inpatient sample 2005 to 2014

BACKGROUND

Cryptococcal disease (CD) confers a higher mortality in cirrhotic patients compared to non-cirrhotic patients. Factor association for CD in cirrhotic patients is poorly understood. Our aim was to determine the incidence, demographic, and comorbidities associated with CD among cirrhotic patients in the United States (US).

METHOD

Retrospective analysis of admissions of cirrhotic patients, with or without CD, using the National Inpatient Sample (NIS) database from 2005 to 2014. The number of admissions were reported in raw and weighted frequencies. The trends of CD among cirrhotic patients and overall CD were evaluated. Rao-Scott chi-square, t-tests, and multivariate logistic regressions were performed to evaluate variables and CD among cirrhotic patients.

RESULTS

There were 886,962 admissions for cirrhosis, and 164 of these with CD. By adjusted odds ratio (AOR), CD was more often associated with cirrhosis in Southern (2.95; 95 % CI 1.24, 7.02) and Western regions (4.45; 95 % CI 1.91, 10.37), Hispanic patients (1.80; 95 % CI 1.01, 3.20), and patients with chronic kidney disease (CKD) (3.13; 95 % CI 2.09, 4.69). Of note, CD in cirrhotic patients was associated with higher inpatient mortality (AOR of 3.89, 95 % CI 2.53, 5.99), longer length of stay (9.87 vs. 4.88 days), and a higher total charge ($76,880 vs. $ 37,227) when compared to cirrhotic patients without CD.

DISCUSSION

Patients with cirrhosis admitted with CD have a high inpatient mortality. The geographical location and CKD were important factors associated with CD among cirrhotic patients. Autoimmune liver diseases and immunosuppression did not appear to increase the risk of CD.

Enhancing oral bioavailability of an antifungal thiazolylhydrazone derivative: Development and characterization of a self-emulsifying drug delivery system

RN104 (2-[2-(cyclohexylmethylene)hydrazinyl)]-4-phenylthiazole) is a thiazolylhydrazone derivative with prominent antifungal activity. This work aimed to develop a self-emulsifying drug delivery system (SEDDS) loaded with RN104 to improve its biopharmaceutical properties and enhance its oral bioavailability. Medium chain triglycerides, sorbitan monooleate, and polysorbate 80 were selected as components for the SEDDS formulation based on solubility determination and a pseudo-ternary phase diagram. The formulation was optimized using the central composite design in response surface methodology. The optimized condition consisted of medium chain triglycerides, sorbitan monooleate, and polysorbate 80 in a mass ratio of 65.5:23.0:11.5, achieving maximum drug loading (10 mg/mL) and minimum particle size (118.4 ± 0.7 nm). The developed RN104-SEDDS was fully characterized using dynamic light scattering, in vitro release studies, stability assessments, polarized light microscopy, and transmission electron microscopy. In vivo pharmacokinetic studies in mice demonstrated that RN104-SEDDS significantly improved oral bioavailability compared to free RN104 (the relative bioavailability was 2133 %). These results clearly indicated the successful application of SEDDS to improve the pharmacokinetic profile and to enhance the oral bioavailability of RN104, substantiating its potential as a promising antifungal drug candidate.

Skin and soft tissue infections in solid organ transplants

PURPOSE OF REVIEW

Skin and soft tissue infections (SSTI) in solid organ transplant (SOT) recipients may be a great challenge for clinicians caring for SOT due to the involvement of both common and opportunistic pathogens associated with a blunted immune response. The purpose of this review is to outline current literature and describe open issues on the management of SSTI in this special population.

RECENT FINDINGS

Clinical presentation in SOT recipients can manifest as isolated skin lesions after primary inoculation or be the sign of a disseminated infection. Tissue samples for microscopy and histopathology are crucial to making an accurate diagnosis given the nonspecific and heterogeneous appearance of skin lesions. Multidisciplinary teams are required for a comprehensive diagnosis and management.

SUMMARY

SSTI are frequent contributors to morbidity and mortality in SOT. Specific research focused on the clinical presentation, risk factors and management in this special population is needed.

Cryptococcosis and Cryptococcal Meningitis: A Narrative Review and the Up-to-Date Management Approach

Cryptococcosis is a fungal infectious disease that enormously impacts human health worldwide. Cryptococcal meningitis is the most severe disease caused by the fungus Cryptococcus, and can lead to death, if left untreated. Many patients develop resistance and progress to death even after treatment. It requires a prolonged treatment course in people with AIDS. This narrative review provides an evidence-based summary of the current treatment modalities and future trial options, including newer ones, namely, 18B7, T-2307, VT-1598, AR12, manogepix, and miltefosine. This review also evaluated the management and empiric treatment of cryptococcus meningitis. The disease can easily evade diagnosis with subacute presentation. Despite the severity of the disease, treatment options for cryptococcosis remain limited, and more research is needed.

Orofacial Cryptococcosis: A Challenging Clinical Report and a Systematic Analysis of the Literature

Cryptococcosis is a neglected fungal disease. The scarcity of studies on oral cryptococcosis is certainly due to rarity and/or underreporting of the disease, especially in Brazil. We describe an example of orofacial cryptococcosis affecting a 57-year-old man after heart transplantation, who presented with multiple erythematous ulcers and erosions distributed in the chin, nasal cavity, labial mucosa, hard palate, and buccal vestibule. Computed tomography revealed opacities and micronodules in the lungs. Histopathological features of the oral and pulmonary lesions were compatible with Cryptococcus spp. Amphotericin B and fluconazole were used for treatment during hospitalization and itraconazole for prolonged therapy after hospital discharge. The patient has been under follow up for 6 months without signs of disease. According to a review conducted in PubMed, Web of Science, Scopus, Embase, and LILACS for data analysis of oral cryptococcosis, 26 reports were described in the literature. Predilection for men was observed (85%), with a male:female ratio of 5.5:1. The mean age of the individuals was 49 ± 15.3 years. Oral cryptococcosis mostly presented as an ulcer (n = 17). The palate and tongue were the most affected sites (n = 9 for each). Amphotericin B was the primary therapy utilized in most patients. Seventeen (65%) individuals survived. Knowledge of the clinicodemographic aspects of oral cryptococcosis is important for clinicians in decision making and surveillance.

Infectious Myelopathies

OBJECTIVE

Infectious myelopathy of any stage and etiology carries the potential for significant morbidity and mortality. This article details the clinical presentation, risk factors, and key diagnostic components of infectious myelopathies with the goal of improving the recognition of these disorders and guiding subsequent management.

LATEST DEVELOPMENTS

Despite our era of advanced multimodal imaging and laboratory diagnostic technology, a causative organism often remains unidentified in suspected infectious and parainfectious myelopathy cases. To improve diagnostic capability, newer technologies such as metagenomics are being harnessed to develop diagnostic assays with a greater breadth of data from each specimen and improvements in infection identification. Conventional assays have been optimized for improved sensitivity and specificity.

ESSENTIAL POINTS

Prompt recognition and treatment of infectious myelopathy decreases morbidity and mortality. The key diagnostic tools include serologies, CSF analysis, and imaging; however clinical presentation, epidemiologic risk factors, and history of recent illness are all vital to making the proper diagnosis because current laboratory and imaging modalities are often inconclusive. The cornerstone of recommended treatment is targeted antimicrobials with appropriate immune modulation, surgical intervention, supportive care, and interdisciplinary involvement, all of which further improve outcomes for patients with infectious myelopathy.

Temporal trends in antifungal susceptibility of Cryptococcus neoformans isolates from a reference laboratory in the United States, 2011-2021

BACKGROUND

There are no established clinical breakpoints for antifungal agents against Cryptococcus species; however, epidemiological cut-off values can help distinguish wild-type (WT) isolates without any acquired resistance from non-WT strains, which may harbour resistance mechanisms.

PATIENTS/METHODS

We describe the trends of antifungal MICs and percentages of WT C. neoformans species complex (CNSC) isolates processed in our reference laboratory from November 2011 to June 2021. There were only nine isolates in 2011, thus, we included them in the year 2012 for data analysis. Clinical data is also described when available.

RESULTS

We identified 632 CNSC, the majority collected from blood (n = 301), cerebrospinal fluid (n = 230), and respiratory (n = 71) sources. The overall percentage of WT isolates for amphotericin B (AMB), 5-flucytosine, and fluconazole was 77%, 98%, and 91%, respectively. We noticed a statistically significant change in the percentage of AMB WT isolates over the years, with 98% of isolates being WT in 2012 compared to 79% in 2021 (p < .01). A similar change was not observed for other antifungal agents. Clinical data was available for 36 patients, primarily non-HIV immunocompromised patients with disseminated cryptococcosis. There were no statistically significant differences in the clinical characteristics and outcomes between patients with WT (58.3%) versus non-WT (41.7%) isolates, but we noticed higher mortality in patients infected with an AMB non-WT CNSC isolate.

CONCLUSIONS

We observed an increase in the percentage of AMB non-WT CNSC isolates in the past decade. The clinical implications of this finding warrant further evaluation in larger studies.

Finger-Prick Whole Blood Cryptococcal Antigen Lateral Flow Assay for the Diagnosis of Cryptococcosis in HIV-Negative Patients: A Case Series Study in Two Tertiary Centers in São Paulo, Brazil

Cryptococcosis in HIV-negative patients can be an opportunistic or endemic disease. There are no published studies on the use of the finger-prick whole blood (point-of-care) cryptococcal antigen lateral flow assay (CrAg LFA) for diagnosing cryptococcosis in HIV-negative patients. We conducted a case series study of HIV-negative patients with cryptococcosis in two centers in São Paulo, Brazil. The objectives were to identify the sensitivity of a finger-prick whole blood CrAg LFA and to describe the main characteristics of this population. We identified 30 HIV-negative patients with cryptococcosis [19 (63%), male; median age, 47 years]. Ten (33%) patients were immunosuppressed, ten (33%) had other comorbidities, and ten (33%) were apparently immunocompetent and without comorbidities. The distribution of the sites of cryptococcosis was as follows: the central nervous system, 90% (n = 27); pulmonary, 43% (n = 13); and other extrapulmonary sites, 40% (n = 12). The sensitivity of the finger-prick whole blood CrAg LFA for the diagnosis of cryptococcosis was 97% (29/30). Among 26 participants with cryptococcal meningitis, the sensitivity of testing cerebrospinal fluid was as follows: CrAg latex agglutination, 77% (20/26); CrAg LFA, 96% (25/26); and culture, 81% (21/26). Culture speciation identified Cryptococcus gattii in 16 (62%) cases, and all had a positive finger-prick whole blood CrAg LFA. This test presented high sensitivity to the diagnosis of cryptococcosis in HIV-negative patients, including those caused by C. gattii.

Clinical and mycological implications of cryptococcal meningitis in Iran

Cryptococcal meningitis (CM) is an uncommon and severe infection that tends to affect both immunocompromised and immunocompetent hosts. To gain insights into the clinical and epidemiological characteristics of CM in Iran, this study evaluated patients with subacute or chronic meningitis referred to 15 Iranian hospitals. Relevant clinical and epidemiological characteristics of the patients were analyzed. Diagnosis of CM cases was performed by microscopic examination, culture, latex agglutination assay, lateral flow assay, and multiplex PCR on cerebrospinal fluid (CSF) samples. The isolates were processed and subjected to molecular identification and in vitro susceptibility antifungal profile. Among the 272 evaluated patients, 7 (2.6 %) CM cases were diagnosed. Out of seven CM cases, 6 (86 %) were male with a median age of 36 years. The most common neurological signs were headache (100 %), followed by nausea and vomiting (71.4 %). All CSF samples from CM patients exhibited positive results across all mycological tests conducted. The isolates were identified as Cryptococcus neoformans (86 %) and Cryptococcus gattii (14 %). All isolates were susceptible to voriconazole and fluconazole, while resistance was observed with itraconazole (MIC value of 0.5 μg/mL) and amphotericin B (MIC values of 4 and 1 μg/mL). The highest mortality (6/7, 86 %) was observed among patients. While a comprehensive study on this subject is currently lacking in Iran, the data acquired through this research play a crucial role in enhancing the clinical and epidemiological understanding of this infection, particularly within low-income countries. Moreover, these findings will serve as a cornerstone for future international comparative studies in this field.

Cryptococcal Meningoencephalitis in Phenotypically Normal Patients

Cryptococcosis is an invasive fungal infection found worldwide that causes significant morbidity and mortality among a broad range of hosts. There are approximately 223,000 new cases of cryptococcosis annually throughout the world, and at least 180,000 deaths are attributed to this infection each year. Most of these are due to complications of cryptococcal meningoencephalitis among HIV-infected patients in resource-limited environments. The majority of individuals diagnosed with cryptococcosis have underlying conditions associated with immune dysfunction such as HIV, solid organ transplant, hematologic malignancy, organ failure syndromes, and/or the use of immunosuppressive agents such as glucocorticosteroids and biologic agents. In most clinical series, there is a small proportion of patients with cryptococcosis who are phenotypically normal; that is, they have no clinically obvious predisposition to disease. Cryptococcal meningoencephalitis (CME) presentation and management differ substantially between these normal individuals and their immunocompromised counterparts. In this review, we will focus on CME in the phenotypically normal host and underscore differences in the clinical presentation, management, outcome, and potential risk factors for these patients compared to immunocompromised persons who develop this potential devastating invasive fungal infection.

Enhancing the antimicrobial activity of silver nanoparticles against ESKAPE bacteria and emerging fungal pathogens by using tea extracts

The sale of antibiotics and antifungals has skyrocketed since 2020. The increasing threat of pathogens like ESKAPE bacteria (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.), which are effective in evading existing antibiotics, and yeasts like Candida auris or Cryptococcus neoformans is pressing to develop efficient antimicrobial alternatives. Nanoparticles, especially silver nanoparticles (AgNPs), are believed to be promising candidates to supplement or even replace antibiotics in some applications. Here, we propose a way to increase the antimicrobial efficiency of silver nanoparticles by using tea extracts (black, green, or red) for their synthesis. This allows for using lower concentrations of nanoparticles and obtaining the antimicrobial effect in a short time. We found that AgNPs synthesized using green tea extract (G-TeaNPs) are the most effective, causing approximately 80% bacterial cell death in Gram-negative bacteria within only 3 hours at a concentration of 0.1 mg mL-1, which is better than antibiotics. Ampicillin at the same concentration (0.1 mg mL-1) and within the same duration (3 h) causes only up to 40% decrease in the number of S. aureus and E. cloacae cells (non-resistant strains). The tested silver nanoparticles also have antifungal properties and are effective against C. auris and C. neoformans, which are difficult to eradicate using other means. We established that silver nanoparticles synthesized with tea extracts have higher antibacterial properties than silver nanoparticles alone. Such formulations using inexpensive tea extracts and lower concentrations of silver nanoparticles show a promising solution to fight various pathogens.

Predictive Performance of Scoring Systems for Mortality Risk in Patients with Cryptococcemia: An Observational Study

Cryptococcal infection is usually diagnosed in immunocompromised individuals and those with meningeal involvement, accounting for most cryptococcosis. Cryptococcemia indicates a poor prognosis and prolongs the course of treatment. We use the scoring systems to predict the mortality risk of cryptococcal fungemia. This was a single hospital-based retrospective study on patients diagnosed with cryptococcal fungemia confirmed by at least one blood culture collected from the emergency department covering January 2012 and December 2020 from electronic medical records in the Taichung Veterans General Hospital. We enrolled 42 patients, including 28 (66.7%) males and 14 (33.3%) females with a mean age of 63.0 ± 19.7 years. The hospital stay ranged from 1 to 170 days (a mean stay of 44.4 days), and the overall mortality rate was 64.3% (27/42). In univariate analysis, the AUC of ROC for MEWS, RAPS, qSOFA, MEWS plus GCS, REMS, NEWS, and MEDS showed 0.833, 0.842, 0.848, 0.846, 0.846, 0.878, and 0.905. In the multivariate Cox regression analysis, all scoring systems, older age, lactate, MAP, and DBP, indicated significant differences between survivor and non-survivor groups. Our results show that all scoring systems could apply in predicting the outcome of patients with cryptococcal fungemia, and the MEDS displays the best performance. We recommend a further large-scale prospective study for patients with cryptococcal fungemia.

Invasive fungal infections in liver diseases

Patients with liver diseases, including decompensated cirrhosis, alcohol-associated hepatitis, and liver transplant recipients are at increased risk of acquiring invasive fungal infections (IFIs). These infections carry high morbidity and mortality. Multiple factors, including host immune dysfunction, barrier failures, malnutrition, and microbiome alterations, increase the risk of developing IFI. Candida remains the most common fungal pathogen causing IFI. However, other pathogens, including Aspergillus, Cryptococcus, Pneumocystis, and endemic mycoses, are being increasingly recognized. The diagnosis of IFIs can be ascertained by the direct observation or isolation of the pathogen (culture, histopathology, and cytopathology) or by detecting antigens, antibodies, or nucleic acid. Here, we provide an update on the epidemiology, pathogenesis, diagnosis, and management of IFI in patients with liver disease and liver transplantation.

Use of Venovenous Extracorporeal Membrane Oxygenation in Patients With Acute Respiratory Distress Syndrome Caused by Fungal Pneumonia

Background: Patients with fungal pneumonias sometimes progress to acute respiratory distress syndrome (ARDS). Mortality has been reported as high as 60% to 90% in this group. Venovenous extracorporeal membrane oxygenation (VV-ECMO) can be used to support such patients, however, outcomes are not well understood. Patients and Methods: This was a retrospective study across the four adult ECMO centers in Minnesota for one decade (2012-2022). The outcomes of interest were duration of ECMO, survival rate, and complications. Data were extracted from the electronic medical record and analyzed using descriptive statistics. Results: Fungal pneumonia was the etiology of ARDS in 22 of 422 (5%) adults supported with VV-ECMO during the 10-year study period. Median patient age was 43 years (interquartile range [IQR], 35-56) and 68% were male. By type of fungal infection, 16 (72%) had blastomycosis, five (22%) had pneumocystis, and one (5%) had cryptococcus. Of the 16 patients with blastomycosis two were immunosuppressed whereas all five of the pneumocystis patients were immunosuppressed. The overall survival rate was 73%; most patients with blastomycosis (67%) and pneumocystis (80%) survived to hospital discharge. The duration of ECMO support was greater for the pneumocystis group (median, 30 days; IQR, 21-43) compared with blastomycosis (median, 10 days; IQR, 8-18). Conclusions: Our findings support the use of VV-ECMO for ARDS caused by fungal pneumonias in select immunocompetent and immunocompromised patients. Although survival was high, patients with pneumocystis required longer ECMO runs.

Neuromeningeal Cryptococcosis and Tuberculosis Coinfection in Bamako: A One-Year Case Series

Cryptococcosis and tuberculosis are life-threatening opportunistic infections that occur in apparently immunocompetent or severely immunocompromised individuals worldwide. As both infections are strongly linked to HIV infection, they may share certain clinical manifestations, and the interaction of their treatments should be considered. However, despite their similarity, concurrent tuberculosis and cryptococcal infections have rarely been reported in West Africa. Herein, we present 3 cases of neuromeningeal cryptococcosis and lung tuberculosis coinfection collected prospectively over a year at the Department of Infectious Diseases of the Point G Teaching Hospital in Bamako. Two patients had HIV disease, and the third patient had no underlying immunosuppressive illnesses. Thus, active screening for tuberculosis and cryptococcosis, particularly in individuals with HIV, can reduce misdiagnosis and ensure appropriate coinfection management. Moreover, this may reduce mortality due to AIDS-related opportunistic infections in resource-limited settings.

Cryptococcal meningoencephalitis: Risk factors associated to death in a hospital in Northeastern Brazil

INTRODUCTION

Cryptococcosis is an opportunistic systemic mycosis caused by pathogenic encapsulated yeasts of the genus Cryptococcus. The objective of the present study was to evaluate the risk factors associated with death of patients diagnosed with meningitis due to Cryptococcus spp.

METHODS

This retrospective cohort study included patients admitted to the São José Hospital (SJH) with Cryptococcal Meningoencephalitis (CM) who were diagnosed between 2010 and 2018. Data collection was carried out by reviewing the patients' medical records. Death during hospitalization was considered the primary outcome.

RESULTS

From 2010 to 2018, 21,519 patients were admitted to the HSJ, 124 of whom were hospitalized due to CM. The CM incidence rate was 5.8 cases/103 hospitalizations. We included 112 patients in the study. Male patients were the most affected (82.1%), and the median age was 37 years [IQR: 29-45]. HIV coinfection occurred in 79.4% of the patients. Fever (65.2%) and headache (88.4%) were the most frequent symptoms. Greater cellularity in the CSF was the most related factor to CM in non-HIV individuals (p < 0.05). Death during hospitalization occurred in 28.6% (n = 32) of the patients. The independent risk factors associated with death during the hospitalization were women (p = 0.009), age > 35 years (p = 0.046), focal neurological deficits (p = 0.013), altered mental status (p = 0.018) and HIV infection (p = 0.040). The twelve-month survival was lower in HIV-positive patients (p < 0.05).

CONCLUSION

Early diagnosis, optimal treatment, and clinical follow-up strategies, especially in HIV patients, should be prioritized.

Adaptive immunology of Cryptococcus neoformans infections-an update

The fungal genus Cryptococcus comprises a group of pathogens with considerable phenotypic and genotypic diversity that can lead to cryptococcosis in both healthy and immunocompromised individuals. With the emergence of the HIV pandemic, cryptococcosis, mainly meningoencephalitis, afflicts HIV-infected patients with severe dysfunction of T cells. It has also been reported in recipients of solid organ transplantation and in patients with autoimmune diseases who take immunosuppressive agents long-term, as well as in those with unidentified immunodeficiency. The clinical outcome of the disease is primarily determined by the immune response resulting from the interplay between the host immune system and the pathogen. Most human infections are caused by Cryptococcus neoformans, and nearly all immunological studies have focused on C. neoformans. This review provides an updated understanding of the role of adaptive immunity during infection with C. neoformans in human and animal models over the past half-decade.

Cerebral Cryptococcosis Associated with CD4+ T-lymphocytopenia in Non-HIV Patients after SARS-CoV-2 Infection: Case Series in a Specialized Institute in Lima, Peru

Cases of cryptococcosis have been reported in patients with COVID-19. The majority are in patients with severe symptoms or who received immunosuppressants. However, there is still no clear association between COVID-19 and cryptococcosis. We report eight cases of cerebral cryptococcosis associated with CD4+ T lymphocytopenia in non-HIV patients after SARS-CoV-2 infection. The median age was 57 years and 5/8 were male. In addition, 2/8 of patients had diabetes, and 8/8 had a history of mild COVID-19, with a median of 75 days before diagnosis of cerebral cryptococcosis. All patients denied having received prior immunosuppressive therapy. The most frequent symptoms were confusion (8/8), headache (7/8), vomiting (6/8), and nausea (6/8) All patients were diagnosed by isolating Cryptococcus in cerebrospinal fluid. The median CD4+ and CD8+ T lymphocytes were 247 and 173.5, respectively. Other causes of immunosuppression, such as HIV or HTLV infection, were excluded in all patients. Finally, three patients died, and one presented long-term visual and auditory sequelae. The CD4+/CD8+ T lymphocyte count normalized during follow-up in those patients who survived. We hypothesize that CD4+ T lymphocytopenia in the patients in this case series could increase the risk of cryptococcosis after SARS-CoV-2 infection.

Clinical Manifestations of Human Exposure to Fungi

Biological particles, along with inorganic gaseous and particulate pollutants, constitute an ever-present component of the atmosphere and surfaces. Among these particles are fungal species colonizing almost all ecosystems, including the human body. Although inoffensive to most people, fungi can be responsible for several health problems, such as allergic fungal diseases and fungal infections. Worldwide fungal disease incidence is increasing, with new emerging fungal diseases appearing yearly. Reasons for this increase are the expansion of life expectancy, the number of immunocompromised patients (immunosuppressive treatments for transplantation, autoimmune diseases, and immunodeficiency diseases), the number of uncontrolled underlying conditions (e.g., diabetes mellitus), and the misusage of medication (e.g., corticosteroids and broad-spectrum antibiotics). Managing fungal diseases is challenging; only four classes of antifungal drugs are available, resistance to these drugs is increasing, and no vaccines have been approved. The present work reviews the implications of fungal particles in human health from allergic diseases (i.e., allergic bronchopulmonary aspergillosis, severe asthma with fungal sensitization, thunderstorm asthma, allergic fungal rhinosinusitis, and occupational lung diseases) to infections (i.e., superficial, subcutaneous, and systemic infections). Topics such as the etiological agent, risk factors, clinical manifestations, diagnosis, and treatment will be revised to improve the knowledge of this growing health concern.

Global Analyses of Multi-Locus Sequence Typing Data Reveal Geographic Differentiation, Hybridization, and Recombination in the Cryptococcus gattii Species Complex

Cryptococcus gattii species complex (CGSC) is a basidiomycete haploid yeast and globally distributed mammalian pathogen. CGSC is comprised of six distinct lineages (VGI, VGII, VGIII, VGIV, VGV, and VGVI); however, the geographical distribution and population structure of these lineages is incompletely described. In this study, we analyze published multi-locus sequence data at seven loci for 566 previously recorded sequence types (STs) encompassing four distinct lineages (VGI, VGII, VGIII, and VGIV) within the CGSC. We investigate indicators of both clonal dispersal and recombination. Population genetic analyses of the 375 STs representing 1202 isolates with geographic information and 188 STs representing 788 isolates with ecological source data suggested historically differentiated geographic populations with infrequent long-distance gene flow. Phylogenetic analyses of sequences at the individual locus and of the concatenated sequences at all seven loci among all 566 STs revealed distinct clusters largely congruent with four major distinct lineages. However, 23 of the 566 STs (4%) each contained alleles at the seven loci belonging to two or more lineages, consistent with their hybrid origins among lineages. Within each of the four major lineages, phylogenetic incompatibility analyses revealed evidence for recombination. However, linkage disequilibrium analyses rejected the hypothesis of random recombination across all samples. Together, our results suggest evidence for historical geographical differentiation, sexual recombination, hybridization, and both long-distance and localized clonal expansion in the global CGSC population.

Fungal Lesions of the Oral Mucosa Diagnosis and Management

Oral fungal infections are opportunistic and due to impaired host resistance. The increasing number of immunosuppressed individuals contributes to rising numbers of mycoses worldwide, and the ease of global migration has allowed the geographic range of endemic mycoses to expand. Deep fungal infections can clinically mimic other pathologic conditions including malignancy. This review highlights the pathogenesis, clinical features, diagnosis, and treatment recommendations of eight fungal infections that can be encountered in the dental setting.

Nanotechnology-Based Approaches for Voriconazole Delivery Applied to Invasive Fungal Infections

Invasive fungal infections increase mortality and morbidity rates worldwide. The treatment of these infections is still limited due to the low bioavailability and toxicity, requiring therapeutic monitoring, especially in the most severe cases. Voriconazole is an azole widely used to treat invasive aspergillosis, other hyaline molds, many dematiaceous molds, Candida spp., including those resistant to fluconazole, and for infections caused by endemic mycoses, in addition to those that occur in the central nervous system. However, despite its broad activity, using voriconazole has limitations related to its non-linear pharmacokinetics, leading to supratherapeutic doses and increased toxicity according to individual polymorphisms during its metabolism. In this sense, nanotechnology-based drug delivery systems have successfully improved the physicochemical and biological aspects of different classes of drugs, including antifungals. In this review, we highlighted recent work that has applied nanotechnology to deliver voriconazole. These systems allowed increased permeation and deposition of voriconazole in target tissues from a controlled and sustained release in different routes of administration such as ocular, pulmonary, oral, topical, and parenteral. Thus, nanotechnology application aiming to delivery voriconazole becomes a more effective and safer therapeutic alternative in the treatment of fungal infections.

Synergistic antifungal interaction of N-(butylcarbamothioyl) benzamide and amphotericin B against Cryptococcus neoformans

Introduction

Cryptococcus neoformans is one of the leading causes of invasive fungal infections worldwide. Cryptococcal meningoencephalitis is the main challenge of antifungal therapy due to high morbidity and mortality rates, especially in low- and middle-income countries. This can be partly attributed to the lack of specific diagnosis difficulty accessing treatment, antifungal resistance and antifungal toxicity.

Methods

In the present study, the effect of the synthetic thiourea derivative N-(butylcarbamothioyl) benzamide (BTU-01), alone and combined with amphotericin B (AmB), was evaluated in planktonic and sessile (biofilm) cells of C. neoformans.

Results

BTU-01 alone exhibited a fungistatic activity with minimal inhibitory concentrations (MICs) ranging from 31.25 to 62.5 μg/mL for planktonic cells; and sessile MICs ranging from 125.0 to 1000.0 μg/mL. BTU-01 caused a concentration-dependent inhibitory activity on cryptococcal urease and did not interfere with plasma membrane fluidity. Molecular docking was performed on Canavalia ensiformis urease, and BTU-01 showed relevant interactions with the enzyme. The combination of BTU-01 and AmB exhibited synergistic fungicidal activity against planktonic and sessile cells of C. neoformans. Microscopic analysis of C. neoformans treated with BTU-01, alone or combined with AmB, revealed a reduction in cell and capsule sizes, changes in the morphology of planktonic cells; a significant decrease in the number of cells within the biofilm; and absence of exopolymeric matrix surrounding the sessile cells. Neither hemolytic activity nor cytotoxicity to mammalian cells was detected for BTU-01, alone or combined with AmB, at concentrations that exhibited antifungal activity. BTU-01 also displayed drug-likeness properties.

Conclusion

These results indicate the potential of BTU-01, for the development of new strategies for controlling C. neoformans infections.

Gene expression profiles of ERG11, MDR1 and AFR1 in Cryptococcus neoformans var.grubbi from HIV patients

Introduction: Fluconazole is the most used antifungal drug for prevention and treatment of Cryptococcus spp. infections, the etiological agent of cryptococcosis. Resistance to fluconazole among Cryptococcus neoformans isolates can lead to treatment failure and generate relapses. Objective: To evaluate the expression profiles of the AFR1, MDR1 and ERG11 genes in C. neoformans var. grubii clinical isolates during the in vitro response to fluconazole induction. Materials and methods: Fourteen C. neoformans var. grubii isolates recovered from HIV patients were studied, in which 6 showed sensitivities to fluconazole and 8 decreased sensitivity. The expression levels of ERG11, AFR1 and MDR1 genes were determined by real-time PCR from extracted mRNA. Results: AFR1 and MDR1 genes from C. neoformans var. grubii were overexpressed in fluconazole resistant isolates, whereas ERG11 maintains homogeneous expression in all the evaluated resistance phenotypes of C. neoformans var. grubii isolates. Conclusions: The overexpression of AFR1 and MDR1 genes, which codify for efflux pumps, contributes to fluconazole resistance in the studied isolates. However, the resistance patterns in this fungus and the relapse cases in HIV patients cannot be attributed solely to the exposure to the drug. Heteroresistance and the emerging resistance (resistance through other ERG genes), might be other mechanisms involved in this phenomenon, which must be studied in these isolations.

Incidental diagnosis of pulmonary cryptococcosis by rebiopsy for epidermal growth factor receptor T790M mutation: A case report

Cryptococcosis is an invasive fungal infection that can occur in cancer patients. A case of pulmonary cryptococcosis in a patient treated with erlotinib + ramucirumab for epidermal growth factor receptor (EGFR) L858R point mutation-positive non-small cell lung cancer is presented. During chemotherapy, a new pulmonary nodule was found and considered progressive disease. Examination of the biopsy specimen taken to identify EGFR T790M mutation incidentally led to the diagnosis of pulmonary cryptococcosis. Three months after taking fluconazole, chest computed tomography showed that the pulmonary nodule had shrunk. New pulmonary nodules during lung cancer treatment require careful attention, not only because of disease progression, but also because of the possibility of infection in an immunocompromised host.

Fun with fungi: a comprehensive review of common fungal organisms encountered in cytology

The ability to detect and diagnose infection is essential in the practice of cytopathology. The identification of suppurative or granulomatous inflammation should prompt careful evaluation for infection. Many of the most commonly encountered fungal organisms demonstrate characteristic microscopic appearances that allow accurate identification even with routine cytology stains, particularly when considered in the context of clinical factors such as geographic location, social history, patient immune status, and symptoms. Given the vital role cytopathologists play in the accurate diagnosis or presumptive identification of infections, this review explores the epidemiology, clinical manifestations, and morphologic features of common fungal pathogens in addition to their differential diagnoses and ancillary testing methods.

Clinical Challenges of Emerging and Re-Emerging Yeast Infections in the Context of the COVID-19 Pandemic

During the geological eras, some fungi, through adaptation and/or environmental/ecological pressure, interacted directly and indirectly with humans, through occasionally harmful interaction interdependent on the individual’s immunological condition. Infections caused by yeasts are underreported, subjugated, and underdiagnosed, and treatment is restricted to a few drugs, even after the significant progress of medicine and pharmacology. In the last centuries, antagonistically, there has been an exponential increase of immunocompromised individuals due to the use of immunosuppressive drugs such as corticosteroids, increased cases of transplants, chemotherapeutics, autoimmune diseases, neoplasms, and, more recently, coronavirus disease 2019 (COVID-19). This review aims to survey emerging and re-emerging yeast infections in the current clinical context. Currently, there is an immense clinical challenge for the rapid and correct diagnosis and treatment of systemic mycoses caused by yeasts due to the terrible increase in cases in the current context of COVID-19.

Analyses of the Global Multilocus Genotypes of the Human Pathogenic Yeast Cryptococcus neoformans Species Complex

Cryptococcus neoformans species complex (CNSC) is a globally distributed human opportunistic yeast pathogen consisting of five major molecular types (VNI, VNII, VNB, VNIII and VNIV) belonging to two species, C. neoformans (VNI, VNII and VNB, collectively called serotype A) and C. deneoformans (VNIV, commonly called serotype D), and their hybrids (VNIII, serotype AD). Over the years, many studies have analyzed the geographical distribution and genetic diversity of CNSC. However, the global population structure and mode of reproduction remain incompletely described. In this study, we analyze the published multilocus sequence data at seven loci for CNSC. The combined sequences at the seven loci identified a total of 657 multilocus sequence types (STs), including 296 STs with known geographic information, representing 4200 non-redundant isolates from 31 countries and four continents. Among the 296 STs, 78 and 52 were shared among countries and continents, respectively, representing 3643 of the 4200 isolates. Except for the clone-corrected serotype D sample among countries, our analysis of the molecular variance of the 4200 isolates revealed significant genetic differentiations among countries and continents in populations of CNSC, serotype A, and serotype D. Phylogenetic analyses of the concatenated sequences of all 657 STs revealed several large clusters corresponding to the major molecular types. However, several rare but distinct STs were also found, representing potentially novel molecular types and/or hybrids of existing molecular types. Phylogenetic incompatibility analyses revealed evidence for recombination within all four major molecular types-VNI, VNII, VNIV and VNB-as well as within two VNB subclades, VNBI and VNBII, and two ST clusters around the most common STs, ST5 and ST93. However, linkage disequilibrium analyses rejected the hypothesis of random recombination across most samples. Together, our results suggest evidence for historical differentiation, frequent recent gene flow, clonal expansion and recombination within and between lineages of the global CNSC population.

Immunologic Diagnosis of Endemic Mycoses

The endemic mycoses blastomycosis, coccidioidomycosis, histoplasmosis, paracoccidioidomycosis, cryptococcosis, sporotrichosis, talaromycosis, adiaspiromycosis, and emergomycosis are mostly caused by geographically limited thermally dimorphic fungi (except for cryptococcosis), and their diagnoses can be challenging. Usual laboratory methods involved in endemic mycoses diagnosis include microscopic examination and culture of biological samples; however, serologic, histopathologic, and molecular techniques have been implemented in the last few years for the diagnosis of these mycoses since the recovery and identification of their etiologic agents is time-consuming and lacks in sensitivity. In this review, we focus on the immunologic diagnostic methods related to antibody and antigen detection since their evidence is presumptive diagnosis, and in some mycoses, such as cryptococcosis, it is definitive diagnosis.

Rare Hepatic Cryptococcosis Mimicked Metastatic Liver Cancer and Confirmed by Metagenomic Next-Generation Sequencing in an Immunocompetent Patient: A Case Report

Background

Cryptococcus neoformans (C. neoformans) is commonly presented in immunocompromised individuals and causes cryptococcosis mostly in the respiratory and/or central nervous system. Liver cryptococcosis is exceedingly rare and sometimes difficult to diagnose through conventional assays.

Case Presentation

The present study reports a rare case of liver cryptococcosis characterized by increased serum carbohydrate antigen 19–9 (CA19-9) level and intrahepatic multiple nodules without other symptoms in an immunocompetent woman. Her cancer family history and imaging examinations initially suspected metastatic liver malignancy. But no sign of the malignant tumor was found after endoscopy, 18-fluorine fluorodeoxyglucose positron emission tomography-computed tomography, and liver biopsy. The histopathology of the liver biopsy specimen indicated chronic inflammatory granuloma and then infectious diseases were suspected. However, traditional microbiologic testing failed to identify any potential pathogen. Eventually, metagenomic next-generation sequencing (mNGS) was applied to identify the definite diagnosis of liver cryptococcosis by acquiring the genome sequence of C. neoformans. Fortunately, after 6-month diagnostic anti-fungal therapy of fluconazole, the liver nodules effectively faded away and the serum CA19-9 level gradually regressed to the normal range.

Conclusion

We identified a rare case of hepatic cryptococcosis by mNGS in an immunocompetent patient. When conventional methods have difficulties in the diagnosis of a specific pathogen, mNGS has the advantage of early and accurate identification of potential pathogens from the specimen.

Primary Cutaneous Cryptococcosis Caused by Cryptococcus gatti in an Elderly Patient

According to the spread of Cryptococcus sp., fungal infections can be classified as primary or secondary. In primary cutaneous cryptococcosis, the fungi are restricted to the skin of the patients, without systemic involvement. The incidence of primary cutaneous cryptococcosis is high in patients with immunosuppression, and this type of infection is rarely observed in patients who are immunocompetent. In the present case report, a patient who is immunocompetent and has systemic comorbidity reported that, after skin trauma, ulcerovegetative lesions appeared in the right upper arm; the etiologic agent was identified as Cryptococcus gatti, serotype B. The cutaneous lesions healed completely after 5 months of fluconazole treatment.

Metagenomic Investigation of Ticks From Kenyan Wildlife Reveals Diverse Microbial Pathogens and New Country Pathogen Records

Focusing on the utility of ticks as xenosurveillance sentinels to expose circulating pathogens in Kenyan drylands, host-feeding ticks collected from wild ungulates [buffaloes, elephants, giraffes, hartebeest, impala, rhinoceros (black and white), zebras (Grévy’s and plains)], carnivores (leopards, lions, spotted hyenas, wild dogs), as well as regular domestic and Boran cattle were screened for pathogens using metagenomics. A total of 75 host-feeding ticks [Rhipicephalus (97.3%) and Amblyomma (2.7%)] collected from 15 vertebrate taxa were sequenced in 46 pools. Fifty-six pathogenic bacterial species were detected in 35 pools analyzed for pathogens and relative abundances of major phyla. The most frequently observed species was Escherichia coli (62.8%), followed by Proteus mirabilis (48.5%) and Coxiella burnetii (45.7%). Francisella tularemia and Jingmen tick virus (JMTV) were detected in 14.2 and 13% of the pools, respectively, in ticks collected from wild animals and cattle. This is one of the first reports of JMTV in Kenya, and phylogenetic reconstruction revealed significant divergence from previously known isolates and related viruses. Eight fungal species with human pathogenicity were detected in 5 pools (10.8%). The vector-borne filarial pathogens (Brugia malayi, Dirofilaria immitis, Loa loa), protozoa (Plasmodium spp., Trypanosoma cruzi), and environmental and water-/food-borne pathogens (Entamoeba histolytica, Encephalitozoon intestinalis, Naegleria fowleri, Schistosoma spp., Toxoplasma gondii, and Trichinella spiralis) were detected. Documented viruses included human mastadenovirus C, Epstein-Barr virus and bovine herpesvirus 5, Trinbago virus, and Guarapuava tymovirus-like virus 1. Our findings confirmed that host-feeding ticks are an efficient sentinel for xenosurveillance and demonstrate clear potential for wildlife-livestock-human pathogen transfer in the Kenyan landscape.

FKS1 Is Required for Cryptococcus neoformans Fitness In Vivo: Application of Copper-Regulated Gene Expression to Mouse Models of Cryptococcosis

There is an urgent need for new antifungals to treat cryptococcal meningoencephalitis, a leading cause of mortality in people living with HIV/AIDS. An important aspect of antifungal drug development is the validation of targets to determine whether they are required for the survival of the organism in animal models of disease. In Cryptococcus neoformans, a copper-regulated promoter (pCTR4-2) has been used previously to modulate gene expression in vivo. The premise for these experiments is that copper concentrations differ depending on the host niche. Here, we directly test this premise and confirm that the expression of CTR4, the promoter used to regulate gene expression, is much lower in the mouse lung compared to the brain. To further explore this approach, we applied it to the gene encoding 1,3-β-glucan synthase, FKS1. In vitro, reduced expression of FKS1 has little effect on growth but does activate the cell wall integrity stress response and increase susceptibility to caspofungin, a direct inhibitor of Fks1. These data suggest that compensatory pathways that reduce C. neoformans resistance do so through posttranscriptional effects. In vivo, however, a less pronounced reduction in FKS1 expression leads to a much more significant reduction in lung fungal burden (~1 log10 CFU), indicating that the compensatory responses to a reduction in FKS1 expression are not as effective in vivo as they are in vitro. In summary, use of copper-regulated expression of putative drug targets in vitro and in vivo can provide insights into the biological consequences of reduced activity of the target during infection. IMPORTANCE Conditional expression systems are widely used to genetically validate antifungal drug targets in mouse models of infection. Copper-regulated expression using the promoter of the CTR4 gene has been sporadically used for this purpose in C. neoformans. Here, we show that CTR4 expression is low in the lung and high in the brain, establishing the basic premise behind this approach. We applied the approach to the study of FKS1, the gene encoding the target of the echinocandin class of 1,3-β-glucan synthase inhibitors. Our in vitro and in vivo studies indicate that C. neoformans tolerates extremely low levels of FKS1 expression. This observation provides a potential explanation for the poor activity of 1,3-β-glucan synthase inhibitors toward C. neoformans.

Genetic Interaction Analysis Reveals that Cryptococcus neoformans Utilizes Multiple Acetyl-CoA-Generating Pathways during Infection

Cryptococcus neoformans is an important human fungal pathogen for which the external environment is its primary niche. Previous work has shown that two nonessential acetyl-CoA metabolism enzymes, ATP-citrate lyase (ACL1) and acetyl-CoA synthetase (ACS1), play important roles in C. neoformans infection. Here, we took a genetic interaction approach to studying the interplay between these two enzymes along with an enzyme initially called ACS2 but which we have found is an acetoacetyl-CoA synthetase; we have renamed the gene 2-ketobutyryl CoA synthetase 1 (KBC1) based on its biochemical activity and the systematic name of its substrate. ACL1 and ACS1 represent a synthetic lethal pair of genes based on our genetic interaction studies. Double mutants of KBC1 with either ACS1 or ACL1 do not have significant synthetic phenotypes in vitro, although we find that deletion of any one of these enzymes reduces fitness within macrophages. Importantly, the acs1Δ kbc1Δ double mutant has significantly reduced fitness in the CNS relative to either single mutant as well as WT (~2 log₁₀ CFU reduction in fungal burden), indicating the important role these enzymes play during infection. The expression of both ACS1 and KBC1 is increased in vivo relative to in vitro conditions. The acs1Δ mutant is hypersusceptible to fluconazole in vivo despite its minimal in vitro phenotypes. These data not only provide insights into the in vivo mechanism of action for a new class of antifungal Acs inhibitors but also into metabolic adaptations of C. neoformans to the host environment.

Cryptococcus neoformans Csn1201 Is Associated With Pulmonary Immune Responses and Disseminated Infection

Cryptococcus neoformans is a major etiological agent of fungal meningoencephalitis. The outcome of cryptococcosis depends on the complex interactions between the pathogenic fungus and host immunity. The understanding of how C. neoformans manipulates the host immune response through its pathogenic factors remains incomplete. In this study, we defined the roles of a previously uncharacterized protein, Csn1201, in cryptococcal fitness and host immunity. Use of both inhalational and intravenous mouse models demonstrated that the CSN1201 deletion significantly blocked the pulmonary infection and extrapulmonary dissemination of C. neoformans. The in vivo hypovirulent phenotype of the csn1201Δ mutant was attributed to a combination of multiple factors, including preferential dendritic cell accumulation, enhanced Th1 and Th17 immune responses, decreased intracellular survival inside macrophages, and attenuated blood–brain barrier transcytosis rather than exclusively to pathogenic fitness. The csn1201Δ mutant exhibited decreased tolerance to various stressors in vitro, along with reduced capsule production and enhanced cell wall thickness under host-relevant conditions, indicating that the CSN1201 deletion might promote the exposure of cell wall components and thus induce a protective immune response. Taken together, our results strongly support the importance of cryptococcal Csn1201 in pulmonary immune responses and disseminated infection.

Emerging Animal-Associated Fungal Diseases

The Global Action Fund for Fungal Infections (GAFFI) estimates that fungal diseases kill around 150 people each hour, and yet they are globally overlooked and neglected. Histoplasma and Talaromyces, which are associated with wildlife, cause systemic infections that are often lethal in patients with impaired cellular immunity. Dermatophytes that cause outbreaks in human hosts are often associated with domesticated animals. Changes in human behavior have been identified as a main cause of the emergence of animal-associated fungal diseases in humans, sometimes caused by the disturbance of natural habitats. An understanding of ecology and the transmission modes of causative agents is therefore essential. Here, we focus on fungal diseases contracted from wildlife and domesticated animals, their habitats, feces and carcasses. We discuss some basic fungal lifestyles and the risk of transmission to humans and illustrate these with examples from emerging and established diseases.

Synergistic combination of duloxetine hydrochloride and fluconazole reduces the cell growth and capsule size of Cryptococcus neoformans

This study aimed to evaluate the effect of duloxetine hydrochloride (DH) on Cryptococcus neoformans. DH minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were 18.5 µg/mL, and the combination with fluconazole (FLZ) reduced the MIC value by 16-and 4-fold for DH and FLZ, respectively. The capsule size decreased by 67% ​​and 16% when treated with DH and DH with FLZ, respectively. Therefore, this study showed that DH is active against C. neoformans alone and in combination with FLZ, leading to the reduction of the capsule size of this yeast.

Three Models of Vaccination Strategies Against Cryptococcosis in Immunocompromised Hosts Using Heat-Killed Cryptococcus neoformans Δsgl1

Vaccines are one of the greatest medical accomplishments to date, yet no fungal vaccines are currently available in humans mainly because opportunistic mycoses generally occur during immunodeficiencies necessary for vaccine protection. In previous studies, a live, attenuated Cryptococcus neoformans Δsgl1 mutant accumulating sterylglucosides was found to be avirulent and protected mice from a subsequent lethal infection even in absence of CD4⁺ T cells, a condition most associated with cryptococcosis (e.g., HIV). Here, we tested three strategies of vaccination against cryptococcosis. First, in our preventative model, protection was achieved even after a 3-fold increase of the vaccination window. Second, because live C. neoformans Δsgl1-vaccinated mice challenged more than once with WT strain had a significant decrease in lung fungal burden, we tested C. neoformans Δsgl1 as an immunotherapeutic. We found that therapeutic administrations of HK C. neoformans Δsgl1 post WT challenge significantly improves the lung fungal burden. Similarly, therapeutic administration of HK C. neoformans Δsgl1 post WT challenge resulted in 100% or 70% survival depending on the time of vaccine administration, suggesting that HK Δsgl1 is a robust immunotherapeutic option. Third, we investigated a novel model of vaccination in preventing reactivation from lung granuloma using C. neoformans Δgcs1. Remarkably, we show that administration of HK Δsgl1 prevents mice from reactivating Δgcs1 upon inducing immunosuppression with corticosteroids or by depleting CD4⁺ T cells. Our results suggest that HK Δsgl1 represents a clinically relevant, efficacious vaccine that confers robust host protection in three models of vaccination against cryptococcosis even during CD4-deficiency.

Pulmonary aspergillosis and cryptococcosis as a complication of COVID-19

Invasive fungal infections may complicate infection by SARS-CoV-2 and increase morbidity and mortality. A 59-year-old man with multiple medical comorbidities was transferred to our hospital for worsening hypoxic respiratory failure due to COVID-19 and received high-dose corticosteroids and 2 doses of cyclophosphamide. He was diagnosed with pulmonary aspergillosis and cryptococcosis by culture of a bronchoalveolar lavage sample. This patient's secondary infections were likely due to treatment with immunosuppressants, his comorbidities, and his prolonged critical illness.

Mediastinal Small Cell Carcinoma with Primary Cutaneous Cryptococcosis: A Rare Case Report

Cutaneous cryptococcosis, an infectious disease resulting from Cryptococcus neoformans, primarily affects immunodeficient individuals. Here, we report a case of mediastinal small cell carcinoma (MSCC) complicated with multiple skin and soft tissue infections mimicking erysipelas and cellulitis. Antibiotics for bacteria were ineffective and a culture of pus from the infected areas revealed Cryptococcus neoformans in this patient. The absence of any evidence indicative of systemic cryptococcal infection leads to a final diagnosis of primary cutaneous cryptococcosis (PCC). Following two weeks of fluconazole at 400 mg/day and 200 mg/day for the subsequent three months, combined with incision, irrigation and drainage, the wound gradually healed. An analysis and discussion of the clinical features of this patient are presented. This case alerts clinicians as to the possibility of Cryptococcus neoformans in patients with advanced malignant tumors complicated with multiple skin and soft tissue infections. While a timely diagnosis and treatment of PCC in this patient resulted in a favorable outcome, the patient succumbed to the malignant tumor at six months post-discharge.