The epidemiology of cryptococcosis and the characterization of Cryptococcus neoformans isolated in a Brazilian University Hospital

Molecular characterization of clinical and environmental isolates from the Cryptococcus neoformans/C. Gattii species complexes of Maceió, Alagoas, Brazil

Cryptococcosis is one of the major life-threatening opportunistic/systemic fungal diseases of worldwide occurrence, which can be asymptomatic or establish pneumonia and meningoencephalitis mainly in immunosuppressed patients, caused by the Cryptococcus neoformans and C. gattii species complexes. Acquisition is by inhaling fungal propagules from avian droppings, tree hollows and decaying wood, and the association of the molecular types with geographic origin, virulence and antifungal resistance have epidemiological importance. Since data on cryptococcosis in Alagoas are limited, we sought to determine the molecular types of etiological agents collected from clinical and environmental sources. We evaluated 21 isolates previously collected from cerebrospinal fluid and from environment sources (pigeon droppings and tree hollows) in Maceió-Alagoas (Brazil). Restriction fragment length polymorphism of URA5 gene was performed to characterize among the eight standard molecular types (VNI-VNIV and VGI-VGIV). Among isolates, 66.67% (14) were assigned to C. neoformans VNI - 12 of them (12/14) recovered from liquor and 2 from a tree hollow (2/14). One isolate from pigeon droppings (4.76%) corresponded to C. neoformans VNIV, while five strains from tree hollows and one from pigeon droppings (6, 28.57%) to C. gattii VGII. VNI-type was present in clinical and environmental samples and most C. neoformans infections were observed in HIV-positive patients, while types VNIV and VGII were prevalent in environmental sources in Alagoas. This is the first molecular characterization of Cryptococcus spp. in Alagoas, our study provides additional information on the ecoepidemiology of Cryptococcus spp. in Brazil, contributing to a closer view of the endemic species.

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.

Clinical and Epidemiological Characteristics of Neurocryptococcosis Associated with HIV in Northeastern Brazil

Cryptococcal meningitis is a serious infection of the central nervous system that is predominant in developing countries, caused by fungi of the genus Cryptococcus, and which affects immunosuppressed patients, especially those with HIV. Here, we aim to diagnose and characterize the clinical-epidemiological profile of cryptococcosis in patients admitted to two tertiary public hospitals in northeastern Brazil. The study is divided into three moments: (1) the isolation of fungus and diagnosis from biological samples collected between 2017 and 2019, (2) a description of the clinical and epidemiological characteristics of the patients, and (3) the experimental tests related to an in vitro susceptibility antifungal profile. The species were identified by MALDI-TOF/MS. Among the 100 patients evaluated, 24 (24.5%) were diagnosed with cryptococcosis based on positive culture. Clinical-epidemiological analysis showed a slightly higher prevalence in men between 30 and 39 years. When comparing the date of HIV diagnosis and the development of cryptococcosis, it was observed that 50% received the diagnosis of infection by cryptococcosis after or equal to a period of 12 months from being diagnosed with HIV; the other 50% received it within the first 30 days of the HIV diagnosis. Neurocryptococcosis was the most prevalent clinical form, and, at the time of hospital admission, the most common clinical signs were high fever (75%), intense headache (62.50%), and neck stiffness (33.33%). The cerebrospinal fluid showed 100% sensitivity and positivity for direct examination by India ink, and fungal culture. The mortality rate in this study was 46% (11/24), a lower rate than in the other literature. An antifungigram showed that 20 (83.33%) isolates were susceptible to amphotericin B and 15 (62.5%) to fluconazole. Mass spectrometry identified 100% of the isolates as Cryptococcus neoformans. In Brazil, this infection is not mandatory notifiable. Therefore, although there is little information on the subject, it is obsolete and does not express the reality of the facts, mainly in the northeast region, where this information is insufficient. The data obtained in this research contribute to the epidemiological knowledge of this mycosis in Brazil and will serve as a basis for future globally comparative epidemiological studies.

Osteoarticular Mycoses

Osteoarticular mycoses are chronic debilitating infections that require extended courses of antifungal therapy and may warrant expert surgical intervention. As there has been no comprehensive review of these diseases, the International Consortium for Osteoarticular Mycoses prepared a definitive treatise for this important class of infections. Among the etiologies of osteoarticular mycoses are Candida spp., Aspergillus spp., Mucorales, dematiaceous fungi, non-Aspergillus hyaline molds, and endemic mycoses, including those caused by Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidioides species. This review analyzes the history, epidemiology, pathogenesis, clinical manifestations, diagnostic approaches, inflammatory biomarkers, diagnostic imaging modalities, treatments, and outcomes of osteomyelitis and septic arthritis caused by these organisms. Candida osteomyelitis and Candida arthritis are associated with greater events of hematogenous dissemination than those of most other osteoarticular mycoses. Traumatic inoculation is more commonly associated with osteoarticular mycoses caused by Aspergillus and non-Aspergillus molds. Synovial fluid cultures are highly sensitive in the detection of Candida and Aspergillus arthritis. Relapsed infection, particularly in Candida arthritis, may develop in relation to an inadequate duration of therapy. Overall mortality reflects survival from disseminated infection and underlying host factors.

Cryptococcosis: Identification of Risk Areas in the Brazilian Amazon

The Brazilian Amazon has a specific epidemiological profile for cryptococcosis, considering its social and economic inequality, health reality, and low access to health services. Furthermore, Brazil and Colombia have the highest cryptococcosis incidence rates in Latin America. In this study, we identified the areas of risk for cryptococcosis in the state of Pará in the Brazilian Amazon. This was an ecological study of patients admitted to a referral hospital from 2008 to 2018, aged 13 years or older, and of both sexes. The spatial distribution was determined using ArcGis 10.3.1 software. Cryptococcosis was confirmed in 272 cases. The incidence rate was 3.41 cases/100,000 inhabitants. Spatial distribution was concentrated in the Metropolitana de Belém, Nordeste Paraense, and Marajó mesoregions. The sociodemographic profile consisted of 62% men, aged between 24 and 34 years (36%), without completed secondary education (64.7%), and with occupations varying between agricultural activities (13.8%) and household activities (22%). The mean hospitalization time was 39 days; the prevalent clinical form was neurological (89.7%). The mortality rate among patients with cryptococcosis was up to 40%. Knowledge of the real magnitude of the disease in the Brazilian Amazon makes it possible to identify areas with the greatest risks and to propose control and epidemiological surveillance programs.

Cryptococcus spp. and Cryptococcosis: focusing on the infection in Brazil

Cryptococcosis is a global fungal infection caused by the Cryptococcus neoformans/Cryptococcus gattii yeast complex. This infection is acquired by inhalation of propagules such as basidiospores or dry yeast, initially causing lung infections with the possibility of progressing to the meninges. This infection mainly affects immunocompromised HIV and transplant patients; however, immunocompetent patients can also be affected. This review proposes to evaluate cryptococcosis focusing on studies of this mycosis in Brazilian territory; moreover, recent advances in the understanding of its virulence mechanism, animal models in research are also assessed. For this, literature review as realized in PubMed, Scielo, and Brazilian legislation. In Brazil, cryptococcosis has been identified as one of the most lethal fungal infections among HIV patients and C. neoformans VNI and C. gattii VGII are the most prevalent genotypes. Moreover, different clinical settings published in Brazil were described. As in other countries, cryptococcosis is difficult to treat due to a limited therapeutic arsenal, which is highly toxic and costly. The presence of a polysaccharide capsule, thermo-tolerance, production of melanin, biofilm formation, mechanisms for iron use, and morphological alterations is an important virulence mechanism of these yeasts. The introduction of cryptococcosis as a compulsory notification disease could improve data regarding incidence and help in the management of these infections.

Early clinical and microbiological predictors of outcome in hospitalized patients with cryptococcal meningitis

Background

Cryptococcal meningitis causes high mortality in immunocompromised and immunocompetent patients. The objective of this study was to identify early predictors of clinical outcome, available at the first days of hospitalization, in patients with cryptococcal meningitis in a tertiary center in Brazil.

Methods

Ninety-six cases of cryptococcal meningitis with clinical, epidemiological and laboratory data, and identification and antifungal susceptibility of the strains were analyzed. Quantitative CSF yeast counts were performed by direct microscopic exam with a Fuchs-Rosenthal cell counting chamber using an institutional protocol. Univariable and multiple analyses using logistic regression were performed to identify predictors, available at the beginning of hospitalization, of in-hospital mortality. Moreover, we performed a secondary analysis for a composite outcome defined by hospital mortality and intensive care unit transfer.

Results

The species and the antifungal susceptibility were not associated with the outcomes evaluated. The variables significantly associated with the mortality were age (OR = 1.08, 95% CI 1.02–1.15), the cerebrospinal fluid (CSF) yeasts count (OR = 1.65, 95% CI 1.20–2.27), systemic arterial hypertension (OR = 22.63, 95% CI 1.64–312.91) and neurological impairment identified by computed tomography (OR = 41.73, 95% CI 3.10–561.65). At the secondary analysis, CSF yeast count was also associated with the composite outcome, in addition to the culture of Cryptococcus spp. from bloodstream and cerebral toxoplasmosis. The associations were consistent with survival models evaluated.

Conclusions

Age and CSF yeast count were independently associated with in-hospital mortality of patients with cryptococcal meningitis but Cryptococcus species identification and antifungal susceptibility were not associated with the outcomes. Quantitative CSF yeast counts used in this study can be evaluated and implemented in other low and middle-income settings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07118-7.

Epidemiological Trends for Cryptococcosis in Swaziland (Eswatini), Southern Africa

Cryptococcosis is a fungal disease that is characterized by inflammation of the lungs and central nervous system, and it is commonly associated with HIV/AIDS. Even though the disease accounts for roughly 15% of all AIDS-related deaths, it is relatively neglected. This is most especially true in Southern Africa which has the highest HIV/AIDS cases in the world and accounts for more than 10% of all HIV/AIDS cases worldwide most especially in Southern African countries such as Swaziland (Eswatini) which has the highest HIV/AIDS adult prevalence rate in the world. Despite this, there are little or no previous studies with regards to the epidemiological trends for cryptococcosis in Swaziland (Eswatini) which further suggests that it is relatively neglected. With the increasing spread of virulent strains of the fungus such as Cryptococcus gattii causing outbreaks in several countries around the world, it is important to have a concrete understanding of the epidemiological trends for cryptococcosis in Swaziland (Eswatini). This is also important during the current coronavirus outbreak as previous studies have reported higher morbidity and mortality rates among COVID-19 patients that are also co-infected with HIV/AIDS, cryptococcus as well as other secondary infections. This is further supported by the fact that Southern Africa has the highest number of COVID-19 cases in Africa as well as one of the highest in the world. As a result, the purpose of this study is to determine the epidemiological trends for cryptococcosis in Swaziland (Eswatini) as this will enable adequate control, management, assessment, policies, and regulations that will be useful during outbreaks. This will be achieved by performing a repeated cross-sectional study to determine the epidemiological changes and trends for cryptococcosis in Swaziland (Eswatini) over a 5-year period from 2023 to 2028.

Identification of Disease-Associated Cryptococcal Proteins Reactive With Serum IgG From Cryptococcal Meningitis Patients

Cryptococcus neoformans, an opportunistic fungal pathogen ubiquitously present in the environment, causes cryptococcal meningitis (CM) mainly in immunocompromised patients, such as AIDS patients. We aimed to identify disease-associated cryptococcal protein antigens targeted by the human humoral immune response. Therefore, we used sera from Colombian CM patients, with or without HIV infection, and from healthy individuals living in the same region. Serological analysis revealed increased titers of anti-cryptococcal IgG in HIV-negative CM patients, but not HIV-positive CM patients, compared to healthy controls. In contrast, titers of anti-cryptococcal IgM were not affected by CM. Furthermore, we detected pre-existing IgG and IgM antibodies even in sera from healthy individuals. The observed induction of anti-cryptococcal IgG but not IgM during CM was supported by analysis of sera from C. neoformans-infected mice. Stronger increase in IgG was found in wild type mice with high lung fungal burden compared to IL-4Rα-deficient mice showing low lung fungal burden. To identify the proteins targeted by human anti-cryptococcal IgG antibodies, we applied a quantitative 2D immunoproteome approach identifying cryptococcal protein spots preferentially recognized by sera from CM patients or healthy individuals followed by mass spectrometry analysis. Twenty-three cryptococcal proteins were recombinantly expressed and confirmed to be immunoreactive with human sera. Fourteen of them were newly described as immunoreactive proteins. Twelve proteins were classified as disease-associated antigens, based on significantly stronger immunoreactivity with sera from CM patients compared to healthy individuals. The proteins identified in our screen significantly expand the pool of cryptococcal proteins with potential for (i) development of novel anti-cryptococcal agents based on implications in cryptococcal virulence or survival, or (ii) development of an anti-cryptococcal vaccine, as several candidates lack homology to human proteins and are localized extracellularly. Furthermore, this study defines pre-existing anti-cryptococcal immunoreactivity in healthy individuals at a molecular level, identifying target antigens recognized by sera from healthy control persons.

A Tale of Two Organ Systems: Imaging review of diseases affecting the thoracic and neurological systems. Part 1

In an era of rapidly expanding knowledge and sub-specialization, it is becoming increasingly common to focus on one organ system. However, the human body is intimately linked, and disease processes affecting one region of the body not uncommonly affect the other organ systems as well. Understanding diseases from a macroscopic perspective, rather than a narrow vantage point, enables efficient and accurate diagnosis. This tenet holds true for diseases affecting both the thoracic and neurological systems; in isolation, the radiologic appearance of disease in one organ system may be nonspecific, but viewing the pathophysiologic process in both organ systems may markedly narrow the differential considerations, and potentially lead to a definitive diagnosis. In this article, we discuss a variety of disease entities known to affect both the thoracic and neurological systems, either manifesting simultaneously or at different periods of time. Some of these conditions may show neither thoracic nor neurological manifestations. These diseases have been systematically classified into infectious, immune-mediated / inflammatory, vascular, syndromic / hereditary and neoplastic disorders. The underlying pathophysiological mechanisms linking both regions and radiologic appearances in both organ systems are discussed. When appropriate, brief clinical and diagnostic information is provided. Ultimately, accurate diagnosis will lead to expedited triage and prompt institution of potentially life-saving treatment for these groups of complex disorders.

Cryptococcal Meningitis in an HIV-Negative Puerperal Woman

Cryptococcal meningitis is a common opportunistic infection in HIV-infected patients and other immunocompromised people. Pregnancy, which is a state of relative immunosuppression, can also be a risk factor for the development of cryptococcal meningitis. We report a clinical case of a 41-year-old woman who developed a severe meningeal syndrome after an otherwise normal pregnancy. Cerebrospinal fluid (CSF) cytochemical analysis presented hypoglycorrhachia, high protein levels, and pleocytosis. Cryptococcal antigen tested positive in serum and CSF, and Cryptococcus neoformans was identified in the CSF culture. The diagnosis of cryptococcal meningitis was confirmed, and antifungal induction therapy was started with liposomal amphotericin B and flucytosine. After clinical improvement, induction therapy was discontinued, and the patient was discharged under maintenance therapy with fluconazole. While under antifungal maintenance therapy, the patient presented worsening of symptoms and a new brain magnetic resonance showed the development of multiple cryptococcoma. Despite sterile CSF cultures, there was a deterioration of the cytochemical parameters. The diagnosis of immune reconstitution inflammatory syndrome was assumed, and after initiation of corticotherapy, the patient improved considerably. This is a rare case of cryptococcal meningitis in a puerperal woman with a challenging management.

Cryptococcus neoformans and Cryptococcus gattii Species Complexes in Latin America: A Map of Molecular Types, Genotypic Diversity, and Antifungal Susceptibility as Reported by the Latin American Cryptococcal Study Group

Cryptococcosis, a potentially fatal mycosis, is caused by members of the Cryptococcus neoformans and Cryptococcus gattii species complexes. In Latin America, cryptococcal meningitis is still an important health threat with a significant clinical burden. Analysis of publicly available molecular data from 5686 clinical, environmental, and veterinary cryptococcal isolates from member countries of the Latin American Cryptococcal Study Group showed that, as worldwide, C. neoformans molecular type VNI is the most common cause of cryptococcosis (76.01%) in HIV-infected people, followed by C. gattii molecular type VGII (12.37%), affecting mostly otherwise healthy hosts. These two molecular types also predominate in the environment (68.60% for VNI and 20.70% for VGII). Among the scarce number of veterinary cases, VGII is the predominant molecular type (73.68%). Multilocus sequence typing analysis showed that, in Latin America, the C. neoformans population is less diverse than the C. gattii population (D of 0.7104 vs. 0.9755). Analysis of antifungal susceptibility data showed the presence of non-wild-type VNI, VGI, VGII, and VGIII isolates in the region. Overall, the data presented herein summarize the progress that has been made towards the molecular epidemiology of cryptococcal isolates in Latin America, contributing to the characterization of the genetic diversity and antifungal susceptibility of these globally spreading pathogenic yeasts.

Predominance of Cryptococcus neoformans Var. grubii in Ahvaz, Molecular Identification and Evaluation of Virulence Factors

Background: Cryptococcus neoformans is an encapsulated yeast pathogen with worldwide distribution, and the highest incidence of cryptococcosis was attributed to C. neoformans (var. grubii. The pathogenicity of Cryptococcus species is associated with several factors, including capsule and melanin production, growth at 37 ºC, and secretion of extracellular enzymes. Objectives: The present study aimed to isolate and identify Cryptococcus species from pigeon guano in Ahvaz, Iran and investigate important virulence factors in the isolates. Methods: Seventy-three isolates of C. neoformans var. grubii were identified based on classical and molecular microbiology methods. Capsule size was measured by the grow yeasts in the presence of 5% CO2. Specific media demonstrated the activity of extracellular enzymes (phospholipase, hemolysin, proteinase, esterase, urease, catalase, and gelatinase). Besides, melanin production was evaluated by the niger seed agar medium. Results: Two hundred and seventeen samples were examined for the presence of Cryptococcus over 165 days in Ahvaz. All tested isolates were contained capsules with variable sizes under 5% CO2 concentration. Moreover, 100% of isolates were produced extracellular enzymes (urease, hemolysin, and catalase), whereas no proteinase and gelatinase activities were observed among isolates. Furthermore, most isolates had phospholipase (93.1%) and esterase activities (86.3%). Also, melanin was produced by all of the isolates. Conclusions: Although two methods were used for recovery of Cryptococcus, only Cryptococcus was isolated from pigeon guano, and swabs from the cage walls were negative. Cryptococcus neoformans var. grubii was the only species from pigeon droppings from Ahvaz with more pathogenic factors. Owing to the high pathogenicity of the isolates, the frequency of the disease is expected to be higher.

In vitro synergistic effects of fluoxetine and paroxetine in combination with amphotericin B against Cryptococcus neoformans

Cryptococcus neoformans is a yeast that mainly affects immunocompromised individuals and causes meningoencephalitis depending on the immune status of the host. The present study aimed to validate the efficacy of selective serotonin reuptake inhibitors, fluoxetine hydrochloride (FLH) and paroxetine hydrochloride (PAH), alone and in combination with amphotericin B (AmB) against C. neoformans. Susceptibility tests were conducted using the broth microdilution method and synergistic effects of combining FLH and PAH with AmB were analyzed using the checkerboard assay. Effects of minimum inhibitory concentration (MIC) and synergistic concentration were evaluated in biofilms by quantifying the biomass, measuring the viability by counting the colony-forming units (CFU/mL) and examining the size of the induced capsules. Cryptococcus neoformans was susceptible to FLH and PAH and the synergistic effect of FLH and PAH in combination with AmB reduced the MIC of AmB by up to 8-fold. The isolated substances and combination with AmB were able to reduce biofilm biomass and biofilm viability. In addition, FLH and PAH alone or in combination with AmB significantly decreased the size of the yeast capsules. Collectively, our results indicate the use of FLH and PAH as a promising prototype for the development of anti-cryptococcal drugs.

Insight into the Assembling Mechanism of Cryptococcus Capsular Glucuronoxylomannan Based on Molecular Dynamics Simulations

Cryptococcus spp. is an invasive fungal pathogen and causes life-threatening cryptococcosis. Opportunistic cryptococcal infections among the immunocompromised population are mostly caused by Cryptococcus neoformans, whereas the geographical dissemination of Cryptococcus gattii in recent years has threatened lives of even immunocompetent people. The capsule, mainly composed of glucuronoxylomannan (GXM) polysaccharides, plays important roles in the virulence of Cryptococcus spp. The assembling mechanism of GXM polysaccharides into the capsule is little understood because of insufficient experimental data. Molecular modeling and molecular dynamics simulation provide insight into the assembling process. We first built GXM oligosaccharide models of serotypes D, A, B, and C and extracted their secondary structure information from simulation trajectories. All the four mainchains tend to take the nearly twofold helical conformation, whereas peripheral sidechains prefer to form left-handed helices, which are further stabilized by intramolecular hydrogen bonds. Based on the obtained secondary structure information, GXM polysaccharide arrays were built to simulate capsule-assembling processes of C. neoformans and C. gattii using serotypes A and C as representatives, respectively. Trajectory analysis illustrates that electrostatic neutralization of acidic sidechain residues of GXM is a prerequisite for capsule assembling, followed by formation of intermolecular hydrogen bond networks. Further insight into the assembling mechanism of GXM polysaccharides provides the possibility to develop novel treatment and prevention solutions for cryptococcosis.

High Prevalence of Cryptococcus neoformans and Isolation of Other Opportunistic Fungi From Pigeon (Columba livia) Droppings in Northeast Iran

Cryptococcus neoformans is an opportunistic human pathogen that causes cryptococcosis, a life-threatening infection that usually manifests as meningoencephalitis in immunocompromised patients. Pigeon (Columba livia) droppings can spread pathogenic yeasts and mold fungi, such as C neoformans, in the environment. The objective of this study was to isolate C neoformans and other opportunistic fungi from feral pigeon droppings. One hundred twenty samples of feral pigeon droppings were suspended 1:10 in saline solution and then cultured. The fungi were identified by standard mycological techniques. Fungal contamination was detected in all examined samples. Yeast and mold fungi were isolated from 114 samples (95%) and 103 samples (85.8%), respectively, out of 120 samples. The highest frequency of yeast and mold fungi isolated from collected samples was C neoformans 77.5% and Rhizopus species 38.3%, respectively. Several types of fungi exist in pigeon droppings that can be spread in the environment and transmitted to children and elderly, as well as immunocompromised patients who are at increased risk of contracting opportunistic diseases.

Multi-locus Sequence Typing and Whole Genome Sequence Analysis of Cryptococcus neoformans Isolated from Clinical Specimens in Vajira Hospital, Bangkok, Thailand

The basidiomycete yeast Cryptococcus neoformans causes disease in immunocompromized patients. Whole genome sequencing (WGS) technology provides insights into the molecular epidemiology of C. neoformans. However, the number of such studies is limited. Here we used WGS and multilocus sequence typing (MLST) to determine the genetic diversity of C. neoformans isolates and genetic structures of their populations among patients admitted to a single hospital in Bangkok, Thailand. Seven isolates from six patients collected during 1 year were identified as C. neoformans sensu stricto according to colony morphology, microscopy, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and nucleotide sequence analysis of internal transcribed sequences. These isolates were sensitive to the antifungal drugs amphotericin B, fluconazole, 5-flucytosine, voriconazole, itraconazole and posaconazole and were mating type α and molecular type VNI. MLST analysis identified ST4, ST5 and ST6. We further employed WGS to determine the genetic diversity and relationships of C. neoformans isolated here combined with C. neoformans sequences data acquired from a public database (n = 42). We used the data to construct a phylogenetic tree. WGS provided additional genomics data and achieved high discriminatory power for identifying C. neoformans isolates isolated in Thailand. This report further demonstrates the applicability of WGS analysis for conducting molecular epidemiology and provides insight into the genetic diversity of C. neoformans isolates from one hospital in Thailand.

Shift in Epidemiology of Cryptococcal Infections in Ottawa with High Mortality in Non-HIV Immunocompromised Patients

Cryptococcus neoformans is a fungus that can cause life-threatening infections. While human immunodeficiency virus (HIV)-positive status historically had the highest risk for cryptococcal infection and was associated with high mortality rates, there have been changes in HIV treatment and the epidemiology of other acquired immunodeficiencies, such as hematological malignancies. We conducted a retrospective case series analysis of patients who had cryptococcal infections documented at the Ottawa Hospital from 2005 to 2017. The Ottawa Hospital is a tertiary care hospital and provides complex care such as chemotherapy and transplantations. There were 28 confirmed cryptococcal infections. The most common underlying condition associated with cryptococcal infection was hematological malignancy (n = 8, 29%), followed by HIV (n = 5, 18%) and solid organ transplantation (n = 4, 14%). Furthermore, while there was a decrease in the number of cryptococcal infections in HIV patients after 2010 (four to one case), the number of cases in non-HIV immunocompromised patients increased from four in the years 2005-2010 to fourteen in 2011-2017. There were nine cryptococcal-attributable deaths. The case fatality rate was highest among patients with underlying hematological malignancies (63%), followed by solid organ transplant (50%) and HIV patients (20%). In conclusion, this study showed that there may be an epidemiological shift of cryptococcal infection in Ottawa. Additionally, infections may be associated with a worse prognosis in patients with a hematological malignancy and solid organ transplant than in patients with HIV infection in the modern era. Better prevention and/or treatment is warranted for high-risk populations.

Cryptococcosis in the Amazon: A current overview and future perspectives

The Amazon region or regional Amazon complex includes nine states of Brazil with an area of around 5.1 million km, which is almost 60% of the country's territory. The sanitary conditions in this region are reflected by illness resulting from substandard living conditions and limited access to prevention measures and health care, in addition to the epidemiological profile of cryptococcosis. This article aims to provide a comprehensive review of the literature on cryptococcosis in the Amazon region and its future prospects. Thus, the present study searched the Scientific Electronic Library Online, Latin American and Caribbean Health Sciences Literature, Medical Literature Analysis and Retrieval System, Virtual Health Library, PubMed, and CAPES Periodical Portal for studies on cryptococcosis in the Amazon region, with an established search period of 1999 to 2018, using the search terms "Cryptococcus," "cryptococcosis," and "Amazon" with the Boolean operator AND. Out of 275 articles found, 29 were selected according to the inclusion criteria and were categorized into clinical and environmental studies. Analysis of these studies verified the increased occurrence of infection by Cryptococcus gattii at younger ages in the supposedly immunocompetent and the predominance of C. neoformans in HIV-positive patients. No occurrence of Cryptococcus laurentii infection has been identified in the literature. The regional endemic molecular types included VNI, VNII, and VGII. Similarly, the strain sequence type (ST) allelic profiles, including ST5, 7, 20, and 264-268, were identified in C. gattii isolated in Amazonas state. VNI isolates are a genetically monotypic group, with ST93 being highly important in HIV individuals. In urban environments, cryptococcosis agents were isolated in samples collected fromtrees, wooden houses, and dove excrement. Due to the absence of a control program and specific epidemiological surveillance for the primary disease, cryptococcal meningitis has become a failure parameter in the treatment of HIV/AIDS patients. The findings of the present study underscore the need for programs to track cryptococcal antigens and identify high-risk populations in order to reduce the morbimortality of this disease.

Prospective cohort of AIDS patients screened for cryptococcal antigenaemia, pre-emptively treated and followed in Brazil

Background

Cryptococcal meningitis has a high morbidity and mortality among AIDS population. Cryptococcal antigen (CrAg) detection is considered an independent predictor for meningitis and death. Since 2011, the World Health Organization recommends CrAg screening for people living with HIV/AIDS (PLHAs) with CD4 counts <100–200 cells/μl. Its implementation is still limited in low-middle-income countries. We aimed to estimate the prevalence and predictors of CrAg positivity in PLHAs. We also evaluated outcomes among those who were CrAg-positive.

Methods

Prospective cohort conducted at an infectious diseases hospital, in Brazil. Adults with CD4 <200 cells/μl, without previous cryptococcal disease and regardless of symptoms, were enrolled from 2015 to 2018. CrAg tests were performed by LFA. Lumbar puncture was done in CrAg+ individuals and pre-emptive therapy was offered for those without meningitis.

Results

Of 214 individuals recruited, 88% were antiretroviral experienced, of which only 11.6% with viral suppression. Overall, CrAg prevalence was 7.9% (95% CI, 4.7–12.4). In CD4 ≤100 cells/μl group it was 7.5% (95% CI, 4.1–12.6) and 9.1% (95% CI, 3.4–19.0) in the group with CD4 101 to 199 cells/μl (p = 0.17). Prevalence in asymptomatic subjects was 5.3% (95% CI, 1.4–13.1). One among 17 CrAg+ participants had documented meningoencephalitis and no subclinical meningitis was detected. Adherence to pre-emptive treatment was 68.7% (11/16). There were no statistically significant differences in sociodemographic, clinical or laboratory characteristics to predict CrAg positivity. No case of cryptococcal disease was diagnosed among CrAg + subjects, followed by a median of 12 months.

Conclusions

CrAg screening for severely immunosuppressed PLHAs in Brazil yielded a prevalence of 7.9%. No difference was found in the prevalence of CrAg stratified by CD4 values (CD4 <100 versus CD4 101–199 cells/μl). No clinical nor laboratory factors predicted CrAg positivity, corroborating the need for the implementation of universal CrAg screening for PLHAs with CD4 <200 cells/μl in similar settings.

Comparison between MALDI-TOF MS and MicroScan in the identification of emerging and multidrug resistant yeasts in a fourth-level hospital in Bogotá, Colombia

Background

The introduction of MALDI-TOF MS in the clinical microbiology laboratory has modified the approaches for the identification of fungi. Thanks to this tool, it is possible to identify cryptic species, which possess critical susceptibility patterns. Clinical strains were identified using the MicroScan and MALDI-TOF MS systems. Discrepant results from both methods were investigated using ITS rDNA barcoding. Finally, these isolates were also tested for in vitro susceptibility.

Results

The percentage of agreement between both methods to 498 yeast isolates was of 93.6% (32 discrepant isolates). The concordance of ITS sequencing with MALDI-TOF MS was higher (99%) than that of MicroScan (94%). Several of these discordant yeasts displayed high MICs for antifungal agents.

Conclusions

Our study highlights the need of the MS and molecular approaches such as MALDI-TOF MS and ITS rDNA barcoding for the correct identification of emerging or cryptic yeast species; besides, some of these could be multidrug resistant.

This work was the first experience in the implementation of the MALDI-TOF MS technology in Colombia. We found the first uncommon yeasts including Candida auris and we could identify Trichosporon faecalis. Our work highlights a clear necessity of an accurate yeast identification as a much more pertinent technique than the susceptibility profiles, because the most unusual yeasts exhibit resistance profiles to the few available antifungals.

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

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

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

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

The Mouse Inhalation Model of Cryptococcus neoformans Infection Recapitulates Strain Virulence in Humans and Shows that Closely Related Strains Can Possess Differential Virulence

Cryptococcal meningitis (CM) causes high rates of HIV-related mortality, yet the Cryptococcus factors influencing patient outcome are not well understood. Pathogen-specific traits, such as the strain genotype and degree of antigen shedding, are associated with the clinical outcome, but the underlying biology remains elusive. In this study, we examined factors determining disease outcome in HIV-infected cryptococcal meningitis patients infected with Cryptococcus neoformans strains with the same multilocus sequence type (MLST). Both patient mortality and survival were observed during infections with the same sequence type. Disease outcome was not associated with the patient CD4 count. Patient mortality was associated with higher cryptococcal antigen levels, the cerebrospinal fluid (CSF) fungal burden by quantitative culture, and low CSF fungal clearance. The virulence of a subset of clinical strains with the same sequence type was analyzed using a mouse inhalation model of cryptococcosis. We showed a strong association between human and mouse mortality rates, demonstrating that the mouse inhalation model recapitulates human infection. Similar to human infection, the ability to multiply in vivo, demonstrated by a high fungal burden in lung and brain tissues, was associated with mouse mortality. Mouse survival time was not associated with single C. neoformans virulence factors in vitro or in vivo; rather, a trend in survival time correlated with a suite of traits. These observations show that MLST-derived genotype similarities between C. neoformans strains do not necessarily translate into similar virulence either in the mouse model or in human patients. In addition, our results show that in vitro assays do not fully reproduce in vivo conditions that influence C. neoformans virulence.

Social, environmental and microbiologic aspects of endemic mycoses in Brazil

Many factors that lead to host immunosuppression are clearly known to predispose the host to fungal diseases, significantly influencing the occurrence of mycoses. However, little or nothing has been discussed regarding social or economic factors that can influence the occurrence of diseases caused by fungi. In this minireview, we discuss several factors that may affect the occurrence of mycoses in Brazil, a continentally extended country that is marked by large climatic variations and severe socioeconomic distortions that may limit access to health services for the population.

The expanding use of matrix-assisted laser desorption/ionization-time of flight mass spectroscopy in the diagnosis of patients with mycotic diseases

INTRODUCTION

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has emerged as a powerful new tool to identify human fungal pathogens and has radically altered the diagnostic mycology workflow at many medical centers around the world. Areas covered: While most experience is with the identification of yeasts, including species of Candida and Cryptococcus, there is ongoing work investigating the role of MALDI-TOF MS to detect molds, including species of Aspergillus, Fusarium, Scedosporium, and Mucormyctes as well as thermally dimorphic fungi. Expert commentary: In this paper, we review the current knowledge about this important new platform and examine how its expanding use may impact molecular diagnostics and patient care in the years ahead.

Amino acid permeases in Cryptococcus neoformans are required for high temperature growth and virulence; and are regulated by Ras signaling

Cryptococcosis is an Invasive Fungal Infection (IFI) caused by Cryptococcus neoformans, mainly in immunocompromised patients. Therapeutic failure due to pathogen drug resistance, treatment inconstancy and few antifungal options is a problem. The study of amino acid biosynthesis and uptake represents an opportunity to explore possible development of novel antifungals. C. neoformans has 10 amino acids permeases, two of them (Aap3 and Aap7) not expressed at the conditions tested, and five were studied previously (Aap2, Aap4, Aap5, Mup1 and Mup3). Our previous results showed that Aap4 and Aap5 are major permeases with overlapping functions. The aap4Δ/aap5Δ double mutant fails to grow in amino acids as sole nitrogen source and is avirulent in animal model. Here, we deleted the remaining amino acid permeases (AAP1, AAP6, AAP8) that showed gene expression modulation by nutritional condition and created a double mutant (aap1Δ/aap2Δ). We studied the virulence attributes of these mutants and explored the regulatory mechanism behind amino acid uptake in C. neoformans. The aap1Δ/aap2Δ strain had reduced growth at 37°C in L-amino acids, reduced capsule production and was hypovirulent in the Galleria mellonella animal model. Our data, along with previous studies, (i) complement the analysis for all 10 amino acid permeases mutants, (ii) corroborate the idea that these transporters behave as global permeases, (iii) are required during heat and nutritional stress, and (iv) are important for virulence. Our study also indicates a new possible link between Ras1 signaling and amino acids uptake.

The X chromosome and sex-specific effects in infectious disease susceptibility

The X chromosome and X-linked variants have largely been ignored in genome-wide and candidate association studies of infectious diseases due to the complexity of statistical analysis of the X chromosome. This exclusion is significant, since the X chromosome contains a high density of immune-related genes and regulatory elements that are extensively involved in both the innate and adaptive immune responses. Many diseases present with a clear sex bias, and apart from the influence of sex hormones and socioeconomic and behavioural factors, the X chromosome, X-linked genes and X chromosome inactivation mechanisms contribute to this difference. Females are functional mosaics for X-linked genes due to X chromosome inactivation and this, combined with other X chromosome inactivation mechanisms such as genes that escape silencing and skewed inactivation, could contribute to an immunological advantage for females in many infections. In this review, we discuss the involvement of the X chromosome and X inactivation in immunity and address its role in sexual dimorphism of infectious diseases using tuberculosis susceptibility as an example, in which male sex bias is clear, yet not fully explored.

Molecular types of Cryptococcus species isolated from patients with cryptococcal meningitis in a Brazilian tertiary care hospital

There are limited data on the molecular epidemiology of cryptococcosis in Brazil. Here, we report on the identification of the molecular pattern of the Cryptococcus species that caused meningitis in patients admitted in a Brazilian reference tertiary care hospital, and review the published studies addressing the molecular epidemiology of Cryptococcus in Brazil. Our study has shown the predominance of molecular type VNII in HIV-infected patients with cryptococcal meningoencephalitis. Molecular types VNII and VGII were occasionally detected in HIV-infected and non-infected patients with meningoencephalitis. In contrast, previous studies have shown that several regions exhibited a high prevalence of the VNI molecular type and sporadic cases of the VNII and VGII molecular types in patients with cryptococcosis in Brazil. Additional studies including VNII isolates will contribute to understanding the epidemiology and phylogenetic relationship of these genotype compared to the other ones. So far, no clear correlation has been established between genotypes, antifungal susceptibility for Cryptococcus and clinical outcome in cryptococcosis.

The status of cryptococcosis in Latin America

Cryptococcosis is a life-threatening fungal infection caused by the encapsulated yeasts Cryptococcus neoformans and C. gattii, acquired from the environment. In Latin America, as occurring worldwide, C. neoformans causes more than 90% of the cases of cryptococcosis, affecting predominantly patients with HIV, while C. gattii generally affects otherwise healthy individuals. In this region, cryptococcal meningitis is the most common presentation, with amphotericin B and fluconazole being the antifungal drugs of choice. Avian droppings are the predominant environmental reservoir of C. neoformans, while C. gattii is associated with several arboreal species. Importantly, C. gattii has a high prevalence in Latin America and has been proposed to be the likely origin of some C. gattii populations in North America. Thus, in the recent years, significant progress has been made with the study of the basic biology and laboratory identification of cryptococcal strains, in understanding their ecology, population genetics, host-pathogen interactions, and the clinical epidemiology of this important mycosis in Latin America.

High-dose fluconazole in combination with amphotericin B is more efficient than monotherapy in murine model of cryptococcosis

Cryptococcus spp., the causative agents of cryptococcosis, are responsible for deaths of hundreds of thousands of people every year worldwide. The drawbacks of available therapeutic options are aggravated by the increased resistance of yeast to the drugs, resulting in inefficient therapy. Also, the antifungal 5FC is not available in many countries. Therefore, a combination of antifungal drugs may be an interesting option, but in vitro and theoretical data point to the possible antagonism between the main antifungals used to treat cryptococcosis, i.e., fluconazole (FLC), and amphotericin B (AMB). Therefore, in vivo studies are necessary to test the above hypothesis. In this study, the efficacy of FLC and AMB at controlling C. gattii infection was evaluated in a murine model of cryptococcosis caused by C. gattii. The infected mice were treated with FLC + AMB combinations and showed a significant improvement in survival as well as reduced morbidity, reduced lung fungal burden, and the absence of yeast in the brain when FLC was used at higher doses, according to the Tukey test and principal component analysis. Altogether, these results indicate that combinatorial optimization of antifungal therapy can be an option for effective control of cryptococcosis.