Cryptococcus in Wildlife and Free-Living Mammals

Cryptococcus neoformans: plant-microbe interactions and ecology

While the opportunistic human pathogens Cryptococcus neoformans and Cryptococcus gattii are often isolated from plants and plant-related material, evidence suggests that these Cryptococcus species do not directly infect plants. Studies find that plants are important for Cryptococcus mating and dispersal. However, these studies have not provided enough detail about how plants and these fungi interact, especially in ways that could show the fungi are capable of causing disease. This review synthesizes recent findings from studies utilizing different plant models associated with the ecology of C. neoformans and C. gattii. Unanswered questions about their environmental role are highlighted. Overall, current research indicates that Cryptococcus utilizes plants as a substrate rather than harming them, arguing against Cryptococcus as a genuine plant pathogen. We hypothesize that plants represent reservoirs that aid dispersal, not hosts vulnerable to infection.

Genetic diversity and antifungal susceptibilities of environmental Cryptococcus neoformans and Cryptococcus gattii species complexes

Cryptococcosis is an opportunistic systemic mycosis caused by Cryptococcus neoformans and C. gattii species complexes and is of increasing global importance. Maintaining continued surveillance of the antifungal susceptibility of environmental C. neoformans and C. gattii isolates is desirable for better managing cryptococcosis by identifying resistant isolates and revealing the emergence of intrinsically resistant species. Relevant research data from Egypt are scarce. Thus, this study aimed to report the genetic diversity of C. neoformans and C. gattii species complexes originating from different environmental sources in Egypt, antifungal susceptibility profiles, antifungal combinations, and correlations of susceptibility with genotypes. A total of 400 environmental samples were collected, 220 from birds and 180 from trees. Cryptococcus spp. were found in 58 (14.5%) of the samples, 44 (75.9%) of the isolates were recovered from birds and 14 (24.1%) from trees. These isolates were genotyped using M13 polymerase chain reaction-fingerprinting and URA5 gene restriction fragment length polymorphism analysis. Of the 31 C. neoformans isolates, 24 (77.4%), 6 (19.4%) and one (4.4%) belonged to VNI, VNII, and VNIII genotypes, respectively. The 27 C. gattii isolates belonged to VGI (70.4%), VGII (18.5%), and VGIII (11.1%) genotypes. Non-wild type C. neoformans and C. gattii isolates that may have acquired resistance to azoles, amphotericin B (AMB), and terbinafine (TRB) were observed. C. gattii VGIII was less susceptible to fluconazole (FCZ) and itraconazole (ITZ) than VGI and VGII. C. neoformans isolates showed higher minimum inhibitory concentrations (MICs) to FCZ, ITZ, and voriconazole (VRZ) than those of C. gattii VGI and VGII. Significant (P < 0.001) correlations were found between the MICs of VRZ and ITZ (r = 0.64) in both C. neoformans and C. gattii isolates, FCZ and TRB in C. neoformans isolates, and FCZ and TRB (r = 0.52) in C. gattii isolates.There is no significant differences in the MICs of TRB in combination with FCZ (P = 0.064) or in combination with AMB (P = 0.543) and that of TRB alone against C. gattii genotypes. By calculating the fractional inhibitory concentration (FIC) index, the combination of FCZ + AMB was synergistic against all tested genotypes. These findings expand our knowledge of ecological niches, genetic diversity, and resistance traits of C. neoformans and C. gattii genotypes in Egypt. Further investigations into how they are related to clinical isolates in the region are warranted.

First case of feline cryptococcosis in Bosnia and Herzegovina

Case summary

A 2-year-old domestic longhair crossbred female cat was referred for a second opinion on a non-healing surgical wound after left eye enucleation. In addition to the left orbital lesion, ulcerative granular masses protruding from the left nostril and on the base of the left ear were noted. A diagnosis of cryptococcosis was established using histopathological examination and a latex cryptococcal antigen agglutination test. The cat was successfully treated with itraconazole.

Relevance and novel information

Cryptococcosis, commonly reported in Australia, western Canada and the western USA, is rarely reported in companion animals in Europe. This marks the first report of cryptococcosis in cats in Bosnia and Herzegovina, emphasising the need to raise awareness within the veterinary community, both local and regional, about this disease.

The CARD9 Gene in Koalas (Phascolarctos cinereus): Does It Play a Role in the Cryptococcus-Koala Interaction?

Cryptococcus is a genus of fungal pathogens that can infect and cause disease in a range of host species and is particularly prominent in koalas (Phascolarctos cinerus). Like other host species, koalas display a range of outcomes upon exposure to environmental Cryptococcus, from external nasal colonization to asymptomatic invasive infection and, in rare cases, severe clinical disease resulting in death. Host factors contributing to these varied outcomes are poorly understood. Due to their close relationship with eucalypt trees (a key environmental niche for Cryptococcus gattii) and suspected continual exposure to the pathogen, koalas provide a unique opportunity to examine host susceptibility in natural infections. Caspase recruitment domain-containing protein 9 (CARD9) is a key intracellular signaling protein in the fungal innate immune response. Humans with mutations in CARD9 succumb to several different severe and chronic fungal infections. This study is the first to sequence and explore CARD9 variation in multiple koalas using Sanger sequencing. Four CARD9 exons were successfully sequenced in 22 koalas from a New South Wales, Australia population. We found minimal variation between koalas across all four exons, an observation that was also made when CARD9 sequences were compared between koalas and six other species, including humans and mice. Ten single-nucleotide polymorphisms (SNP) were identified in this study and explored in the context of cryptococcal exposure outcomes. While we did not find any significant association with variation in cryptococcal outcomes, we found a high degree of conservation between species at several SNP loci that requires further investigation. The findings from this study lay the groundwork for further investigations of CARD9 and Cryptococcus both in koalas and other species, and highlight several considerations for future studies.

A case report of cryptococcosis in a captive Cape hyrax (Procavia capensis)

Cryptococcosis, a globally distributed mycotic disease caused by Cryptococcus neoformans or C. gattii, has been extensively studied in various domestic animals and humans. However, non-domestic species have often been overlooked in the literature, with limited attention given to their susceptibility and contribution to the epidemiology of the disease. In this study, a captive two-year-old Cape hyrax in a Japanese zoo exhibited neurological symptoms and torticollis, ultimately succumbing to the infection. Necropsy and pathological analyses, including histopathological techniques and PCR, revealed the presence of C. neoformans in the lungs, cerebrum, and internal auditory canal. While cryptococcosis has been reported in various wild animals globally, this case represents the first documented cryptococcosis in Cape hyrax.

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.

Potential Fungal Zoonotic Pathogens in Cetaceans: An Emerging Concern

Over 60% of emerging infectious diseases in humans are zoonotic, often originating from wild animals. This long-standing ecological phenomenon has accelerated due to human-induced environmental changes. Recent data show a significant increase in fungal infections, with 6.5 million cases annually leading to 3.7 million deaths, indicating their growing impact on global health. Despite the vast diversity of fungal species, only a few are known to infect humans and marine mammals. Fungal zoonoses, especially those involving marine mammals like cetaceans, are of global public health concern. Increased human-cetacean interactions, in both professional and recreational settings, pose risks for zoonotic disease transmission. This review focuses on the epidemiology, clinical manifestations, and zoonotic potential of major fungal pathogens shared in humans and cetaceans, highlighting their interspecies transmission capability and the challenges posed by antifungal resistance and environmental changes. It underscores the need for enhanced awareness and preventative measures in high-risk settings to protect public health and marine ecosystems.

The Ecology of Non-Candida Yeasts and Dimorphic Fungi in Cetaceans: From Pathogenicity to Environmental and Global Health Implications

Cetaceans, which are integral to marine ecosystems, face escalating anthropogenic threats, including climate change and pollution, positioning them as critical sentinel species for ocean and human health. This review explores the neglected realm of non-Candida yeasts in cetaceans, addressing the gaps in the understanding of their prevalence, pathogenicity, and environmental impacts. By examining identified species such as Cryptococcus spp., Paracoccidioides spp., and several dimorphic fungi, this review emphasizes global prevalence, epidemiology and ecology, pathogenicity, and potential zoonotic implications. It also discusses the fine line between yeast commensalism and pathogenicity by considering environmental influences such as pollution, climate shifts, and immune suppression. Environmental impact discussions delve into how rising ocean temperatures and pollution can modify yeast mycobiota, potentially affecting marine host health and broader ecosystem dynamics. The cetacean's unique physiology and ecological niches are considered, highlighting potential impacts on behaviors, reproductive success, and survival rates. Identifying crucial knowledge gaps, the review calls for intensified research efforts, employing advanced molecular techniques to unravel the cetacean mycobiome. Systematic studies on yeast diversity, antifungal susceptibility, and their influence on environmental and ecosystem health are proposed, and the balance between commensal and pathogenic species emphasizes the significance of the One Health approach. In conclusion, as marine mammals face unprecedented challenges, unveiling non-Candida yeasts in cetaceans emerges as a critical endeavor with far-reaching implications for the conservation of marine ecosystems and for both animal and human public health.

Accumulation of endogenous free radicals is required to induce titan-like cell formation in Cryptococcus neoformans

IMPORTANCE

Cryptococcus neoformans is an excellent model to investigate fungal pathogenesis. This yeast can produce "titan cells," which are cells of an abnormally larger size that contribute to the persistence of the yeast in the host. In this work, we have used a new approach to characterize them by identifying drugs that inhibit this process. We have used a repurposing off-patent drug library, combined with an automatic method to image and analyze fungal cell size. In this way, we have identified many compounds that inhibit this transition. Interestingly, several compounds were antioxidants, allowing us to confirm that endogenous ROS and mitochondrial changes are important for titan cell formation. This work provides new evidence of the mechanisms required for titanization. Furthermore, the future characterization of the inhibitory mechanisms of the identified compounds by the scientific community will contribute to better understand the role of titan cells in virulence.

Bat-associated microbes: Opportunities and perils, an overview

The potential biotechnological uses of bat-associated bacteria are discussed briefly, indicating avenues for biotechnological applications of bat-associated microbes. The uniqueness of bats in terms of their lifestyle, genomes and molecular immunology may predispose bats to act as disease reservoirs. Molecular phylogenetic analysis has shown several instances of bats harbouring the ancestral lineages of bacterial (Bartonella), protozoal (Plasmodium, Trypanosoma cruzi) and viral (SARS-CoV2) pathogens infecting humans. Along with the transmission of viruses from bats, we also discuss the potential roles of bat-associated bacteria, fungi, and protozoan parasites in emerging diseases. Current evidence suggests that environmental changes and interactions between wildlife, livestock, and humans contribute to the spill-over of infectious agents from bats to other hosts. Domestic animals including livestock may act as intermediate amplifying hosts for bat-origin pathogens to transmit to humans. An increasing number of studies investigating bat pathogen diversity and infection dynamics have been published. However, whether or how these infectious agents are transmitted both within bat populations and to other hosts, including humans, often remains unknown. Metagenomic approaches are uncovering the dynamics and distribution of potential pathogens in bat microbiomes, which might improve the understanding of disease emergence and transmission. Here, we summarize the current knowledge on bat zoonoses of public health concern and flag the gaps in the knowledge to enable further research and allocation of resources for tackling future outbreaks.

Fungi's Swiss Army Knife: Pleiotropic Effect of Melanin in Fungal Pathogenesis during Cattle Mycosis

Fungal threats to public health, food security, and biodiversity have escalated, with a significant rise in mycosis cases globally. Around 300 million people suffer from severe fungal diseases annually, while one-third of food crops are decimated by fungi. Vertebrate, including livestock, are also affected. Our limited understanding of fungal virulence mechanisms hampers our ability to prevent and treat cattle mycoses. Here we aim to bridge knowledge gaps in fungal virulence factors and the role of melanin in evading bovine immune responses. We investigate mycosis in bovines employing a PRISMA-based methodology, bioinformatics, and data mining techniques. Our analysis identified 107 fungal species causing mycoses, primarily within the Ascomycota division. Candida, Aspergillus, Malassezia, and Trichophyton were the most prevalent genera. Of these pathogens, 25% produce melanin. Further research is required to explore the involvement of melanin and develop intervention strategies. While the literature on melanin-mediated fungal evasion mechanisms in cattle is lacking, we successfully evaluated the transferability of immunological mechanisms from other model mammals through homology. Bioinformatics enables knowledge transfer and enhances our understanding of mycosis in cattle. This synthesis fills critical information gaps and paves the way for proposing biotechnological strategies to mitigate the impact of mycoses in cattle.

CRYPTOCOCCOSIS: A bibliographic narrative review on antifungal resistance

Cryptococcosis is an infectious fungal disease widely studied for its epidemiological importance in the context of public health, given the high morbidity and mortality associated with this invasive fungal infection. Many cases of the disease present clinical resistance and progress to death, even in the presence of antifungal therapy. The prolonged use of triazole drugs to maintain the treatment of cryptococcosis in AIDS patients, can lead to selective pressure from mutant strains, among other resistance mechanisms, justifying the poor clinical evolution of some cases. In this study, a narrative review of the literature on the occurrence of antifungal resistance in cryptococcosis agents was performed. Publications from 2010 to 2022 that address this topic were selected using Google Scholars and Scopus website. Data from the studies were analyzed for the values of minimum inhibitory concentration (MIC) of drugs used in the management of cryptococcosis. The review showed that the highest MIC values occurred for voriconazole, especially against C. neoformans. It is concluded that there is a lack of studies with statistical analysis of the data obtained, in order to provide a better dimensioning of the resistance rates of cryptococcosis agents to different antifungal agents, both in geographical and temporal context.

Eumycetoma Caused by Madurella pseudomycetomatis in a Captive Tiger (Panthera tigris)

A captive-kept adult male tiger presented with a large cutaneous and subcutaneous mass on the thigh with a fistula. During sedation, multiple nodules were detected and samples for a histopathological exam were collected. Histologically, granulomatous panniculitis and dermatitis were seen around dense aggregates of pigmented fungal hyphae, and a diagnosis of phaeohyphomycosis was made; considering the clinical features, it was classified as a eumycotic mycetoma. This is a rarely reported subcutaneous fungal infection in humans and animals, caused by dematiaceous fungi. Clinically, it is characterized by tumefaction, fistulous sinus tracts, and the formation of macroscopically visible grains. In the literature, only a few infections in wild felids have been reported. In this case, Fontana-Masson staining better showed pigmentation and panfungal PCR and sequencing identified Madurella pseudomyectomatis (OP623507) as the causative agent. Systemic therapy with oral administration of itraconazole was planned, but the patient died during the first period of treatment. The animal was not submitted for post-mortem examination. Visceral dissemination of the agent cannot be excluded. To the authors' knowledge, this is the first report of eumycotic mycetoma by Madurella pseudomycetomatis in a captive tiger.

Pulmonary Cryptococcosis

Pulmonary cryptococcosis describes an invasive lung mycosis caused by Cryptococcus neoformans or Cryptococcus gattii complex. It is often a high-consequence disease in both immunocompromised and immunocompetent populations, and may be misdiagnosed as pulmonary malignancy, leading to a delay in therapy. Epidemiology follows that of cryptococcal meningoencephalitis, with C. gattii infection more common in certain geographic regions. Diagnostic tools include histopathology, microscopy and culture, and the detection of cryptococcal polysaccharide antigen or Cryptococcus-derived nucleic acids. All patients with lung cryptococcosis should have a lumbar puncture and cerebral imaging to exclude central nervous system disease. Radiology is key, both as an adjunct to laboratory testing and as the initial means of detection in asymptomatic patients or those with non-specific symptoms. Pulmonary cryptococcomas (single or multiple) may also be associated with disseminated disease and/or cryptococcal meningitis, requiring prolonged treatment regimens. Optimal management for severe disease requires extended induction (amphotericin B and flucytosine) and consolidation therapy (fluconazole) with close clinical monitoring. Susceptibility testing is of value for epidemiology and in regions where relatively high minimum inhibitory concentrations to azoles (particularly fluconazole) have been noted. Novel diagnostic tools and therapeutic agents promise to improve the detection and treatment of cryptococcosis, particularly in low-income settings where the disease burden is high.

Important Mycoses of Wildlife: Emphasis on Etiology, Epidemiology, Diagnosis, and Pathology—A Review: PART 1

Simple Summary

The number of wild animals is steadily declining globally, so the early diagnosis and proper treatment of emerging diseases are vital. Fungal diseases are commonly encountered in practice and have a high zoonotic potential. This article describes aspergillosis, candidiasis, histoplasmosis, cryptococcosis, and penicilliosis, and is only the first part of a detailed review. The laboratory methods (fungal isolation, gross pathology, histopathology, histochemistry, cytology, immunohistochemistry, radiography, CT, PCR, or ELISA) used in the diagnosis and the clinical details that provide a complete view of the mycoses are presented.

Abstract

In the past few years, there has been a spurred tripling in the figures of fungal diseases leading to one of the most alarming rates of extinction ever reported in wild species. Some of these fungal diseases are capable of virulent infections and are now considered emerging diseases due to the extremely high number of cases diagnosed with fungal infections in the last few decades. Most of these mycotic diseases in wildlife are zoonotic, and with the emergence and re-emergence of viral and bacterial zoonotic diseases originating from wildlife, which are causing devastating effects on the human population, it is important to pay attention to these wildlife-borne mycotic diseases with zoonotic capabilities. Several diagnostic techniques such as fungal isolation, gross pathology, histopathology, histochemistry, cytology, immunohistochemistry, radiography, CT, and molecular methods such as PCR or ELISA have been invaluable in the diagnosis of wildlife mycoses. The most important data used in the diagnosis of these wildlife mycoses with a zoonotic potential have been re-emphasized. This will have implications for forestalling future epidemics of these potential zoonotic mycotic diseases originating from wildlife. In conclusion, this review will highlight the etiology, epidemiology, diagnosis, pathogenesis, pathogenicity, pathology, and hematological/serum biochemical findings of five important mycoses found in wild animals.

A novel alphaherpesvirus and concurrent respiratory cryptococcosis in a captive koala ( Phascolarctos cinereus )

A novel alphaherpesvirus was detected in a captive adult, lactating, female koala (Phascolarctos cinereus) admitted to James Cook University Veterinary Emergency Teaching & Clinical Hospital in March 2019, showing signs of anorexia and severe respiratory disease. Postmortem examination revealed gross pathology indicative of pneumonia. Histopathology demonstrated a chronic interstitial pneumonia, multifocal necrotising adrenalitis and hepatitis. Intranuclear inclusion bodies were detected by light microscopy in the respiratory epithelium of the bronchi, bronchioles, alveoli, and hepatocytes, biliary epithelium and adrenal gland associated with foci of necrosis. Cryptococcus gattii was isolated from fresh lung on necropsy, positively identified by PCR, and detected histologically by light microscopy, only in the lung tissue. A universal viral family‐level PCR indicated that the virus was a member of the Herpesviruses. Sequence analysis in comparison to other known and published herpesviruses, indicated the virus was a novel alphaherpesvirus, with 97% nucleotide identity to macropodid alphaherpesvirus 1. We provisionally name the novel virus phascolarctid alphaherpesvirus 3 (PhaHV‐3). Further research is needed to determine the distribution of this novel alphaherpesvirus in koala populations and establish associations with disease in this host species.

A Possible Link between the Environment and Cryptococcus gattii Nasal Colonisation in Koalas (Phascolarctos cinereus) in the Liverpool Plains, New South Wales

Cryptococcosis caused by yeasts of the Cryptococcus gattii species complex is an increasingly important mycological disease in humans and other mammals. In Australia, cases of C. gattii-related cryptococcosis are more prevalent in the koala (Phascolarctos cinereus) compared to humans and other animals, likely due to the close association that both C. gattii and koalas have with Eucalyptus species. This provides a cogent opportunity to investigate the epidemiology of spontaneous C. gattii infections in a free-living mammalian host, thereby offering insights into similar infections in humans. This study aimed to establish a link between nasal colonisation by C. gattii in free-ranging koalas and the tree hollows of Eucalyptus species, the key environmental source of the pathogen. We (i) detected and genotyped C. gattii from nine out of 169 free-ranging koalas and representative tree hollows within their home range in the Liverpool Plains, New South Wales, and (ii) examined potential environmental predictors of nasal colonisation in koalas and the presence of C. gattii in tree hollows. Phylogenetic analyses based on multi-locus sequence typing (MLST) revealed that the koalas were most likely colonised by the most abundant C. gattii genotypes found in the Eucalyptus species, or closely related genotypes. Importantly, the likelihood of the presence of C. gattii in tree hollows was correlated with increasing hollow size.

Nasopharyngeal cryptococcosis in a cat: interlaboratory variation in cryptococcal antigen assay test results

Case summary

An indoor-only 6-year-old spayed female domestic cat was evaluated for a history of stertorous respiration. Skull radiographs revealed increased soft tissue density within the caudal aspect of the left nasal cavity. CT and rhinoscopy revealed a mass lesion in the choana, plus a smaller lesion, nearly completely occluding flow through the nasal passages. Rhinoscopy was used to collect a biopsy specimen from a fleshy, tan–yellow mass visualized in the caudal nasopharynx. Histopathology was diagnostic for Cryptococcus species infection and systemic antifungal therapy with fluconazole was initiated. Following a series of discordant results, serum samples were submitted to a veterinary diagnostic laboratory that utilized a cryptococcal antigen latex agglutination system with pretreatment of serum with pronase. Twenty-three months after the initial diagnosis, the cat’s serum cryptococcal antigen titer declined to 1:5 and the cat has responded well to continuing treatment.

Relevance and novel information

This case illustrates challenges associated with discordant test results for cryptococcal antigen among laboratories. Discordancies may be due to differences in assay design, or the underlying disease state itself, or whether serum is pre-treated with pronase; with some tests relying on the training and experience of the operator if the cryptococcal antigen detection test requires a subjective interpretation. It also resolves some confusion in the literature related to the assay types available and terminology used to describe them, and emphasizes the importance of considering cryptococcosis as an important differential for cats with upper respiratory signs, without nasal discharge, even if the cat is kept exclusively indoors.

Epidemiological and Clinical Characteristics, Antifungal Susceptibility, and MLST-Based Genetic Analysis of Cryptococcus Isolates in Southern Taiwan in 2013-2020

Cryptococcal meningoencephalitis (CM) is a treatable condition, but it leads to excessive morbidity and mortality. We collected 115 non-duplicated Cryptococcus clinical isolates during 2013−2020 in southern Taiwan to perform antifungal susceptibility testing. Multi-locus sequence typing was performed on 96 strains from patients with CM (n = 47) or cryptococcemia (n = 49). In addition, the epidemiological and clinical characteristics of patients with CM during 2013−2020 (n = 47) were compared with those during 2000−2010 (n = 46). During 2013−2020, only one C. neoformans isolate (0.9%) had a fluconazole minimum inhibitory concentration of >8 μg/mL. Amphotericin B (AMB), flucytosine (5FC), and voriconazole were highly active against all C. neoformans/C. gattii isolates. The most common sequence type was ST5. Among these 47 patients with CM, cerebrospinal fluid cryptococcal antigen (CSF CrAg) titer >1024 was a significant predictor of death (odds ratio, 48.33; 95% CI, 5.17−452.06). A standard induction therapy regimen with AMB and 5FC was used for all patients during 2013−2020, but only for 2.2% of patients in 2000−2010. The in-hospital CM mortality rate declined from 39.1% during 2000−2010 to 25.5% during 2013−2020, despite there being significantly younger patients with less CSF CrAg >1024 during 2000−2010. The study provides insight into the genetic epidemiology and antifungal susceptibility of Cryptococcus strains in southern Taiwan. The recommended antifungal drugs, AMB, 5FC, and FCZ, remained active against most of the Cryptococcus strains. Early diagnosis of patients with CM and adherence to the clinical practice guidelines cannot be overemphasized to improve the outcomes of patients with CM.

Comparison of laboratory diagnosis, clinical manifestation, and management of pulmonary cryptococcosis: Report of the clinical scenario and literature review

BACKGROUND

Pulmonary cryptococcosis is an opportunistic aggressive mycosis in immunocompromised patients, but it can be increasingly seen in immunocompetent patients. It is still challenging to make a rapid and accurate diagnosis due to the various clinical manifestations and limitations in the diagnostic tools.

METHOD

A 54-year-old man presented with intermittent productive cough and fever for 1 week. A chest X-ray demonstrated multiple consolidations in both lungs. Blood biochemistry indicated elevated immunoglobulin G levels. Including sputum cultures, polymerase chain reaction (PCR) tests for severe acute respiratory syndrome coronavirus 2, influenza A and B virus were all negative. Computed tomography of the chest showed ground-glass opacities with a nodular pattern. The serum cryptococcal antigen test was positive; however, the cerebral spinal fluid was negative. The diagnosis of pulmonary cryptococcal infection was made. An initial bronchoscopy was performed unsuccessfully and the patient received intravenous fluconazole therapy for 2 weeks. Due to poor improvement of clinical condition, he then underwent a surgical lung biopsy. The pathology revealed several encapsulated yeast cells, diffuse pulmonary interstitial fibrosis, noncaseating granulomas surrounded by T lymphocytes and multinucleated giant cells with intracellular inclusions, confirming pulmonary yeast infection associated with hypersensitivity pneumonitis. Ultimately, fungal cultures of the pathology samples revealed Cryptococcus neoformans. Subsequently antifungal therapy combined with oral steroid treatment, his general condition improved. After a total of 6 months of antifungal therapy, the patient recovered completely.

CONCLUSIONS

Applicable laboratory diagnosis can help facilitate the accurate and rapid diagnosis of pulmonary cryptococcosis. This report elected to provide an update on the topic of laboratory diagnosis, clinical manifestation, and management of pulmonary cryptococcosis.

Epizootiology of a Cryptococcus gattii outbreak in porpoises and dolphins from the Salish Sea

Cryptococcus gattii is a fungal pathogen that primarily affects the respiratory and nervous systems of humans and other animals. C. gattii emerged in temperate North America in 1999 as a multispecies outbreak of cryptococcosis in British Columbia (Canada) and Washington State and Oregon (USA), affecting humans, domestic animals, and wildlife. Here we describe the C. gattii epizootic in odontocetes. Cases of C. gattii were identified in 42 odontocetes in Washington and British Columbia between 1997 and 2016. Species affected included harbor porpoises Phocoena phocoena (n = 26), Dall's porpoises Phocoenoides dalli (n = 14), and Pacific white-sided dolphins Lagenorhynchus obliquidens (n = 2). The probable index case was identified in an adult male Dall's porpoise in 1997, 2 yr prior to the initial terrestrial outbreak. The spatiotemporal extent of the C. gattii epizootic was defined, and cases in odontocetes were found to be clustered around terrestrial C. gattii hotspots. Case-control analyses with stranded, uninfected odontocetes revealed that risk factors for infection were species (Dall's porpoises), age class (adult animals), and season (winter). This study suggests that mycoses are an emerging source of mortality for odontocetes, and that outbreaks may be associated with anthropogenic environmental disturbance.

An analysis of the population of Cryptococcus neoformans strains isolated from animals in Poland, in the years 2015-2019

Fungi belonging to the Cryptococcus neoformans/C. gattii species complex (CNGSC) are pathogens causing severe infections in humans and animals, that for humans may result in a mortality rate ranging up to 70%. The CNGSC is divided into eight major molecular types, that may differ in their virulence and susceptibility. In order to fully understand the epidemiology of cryptococcosis, it is important to study the world distribution and population structure of these pathogens. The present study is the first presenting a population of strains isolated in Poland and one of the few using a multi-species animal group as a source of the specimen. The pathogen was present in 2.375% of the tested animals. The URA5-RFLP and MALDI-TOF MS analyses have revealed that the population consisted exclusively of C. neoformans strains, with a predominance of major molecular type VNIV (C. neoformans var. neoformans). The MALDI-TOF MS was used to perform the CNGSC strains identification on both the species and sub-species level. Despite the fact that the animals providing the specimens were not treated with 5-fluorocytosine, around 10% of the tested population presented MIC values exceeding 64 mg/L, indicating the existence of the 5-fluorocytosine-resistant strains in the environment.