Cryptococcus neoformansvarietygattii

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.

Minimum inhibitory concentrations of antifungals against invasive isolates of Cryptococcus species worldwide: Global antifungal antimicrobial testing leadership and surveillance program, 2010-2020

This study examined the geographic distribution of minimum inhibitory concentrations (MICs) of antifungals against Cryptococcus isolates. Data were collected on the MICs of specific antifungals (amphotericin B, 5-flucytosine, fluconazole, voriconazole, posaconazole, and isavuconazole) against various Cryptococcus species for the period 2010 to 2020 from the Antimicrobial Testing Leadership and Surveillance database. Cryptococcus isolates were collected from samples of blood and cerebrospinal fluid (CSF) from patients hospitalized in different regions worldwide. We applied the epidemiological cutoff values (ECVs) of antifungals against various Cryptococcus species to distinguish wild-type (WT) from non-WT Cryptococcus isolates. A total of 395 isolates of Cryptococcus species cultured from blood (n = 201) or CSF (n = 194) were analyzed. C. grubii (n = 270), C. neoformans (n = 111), and C. gattii (n = 11) were the three predominant species causing bloodstream infections (BSI) or meningitis/meningoencephalitis (MME). The proportion of MICs above the ECV (1 mg/L) for amphotericin B among C. neoformans isolates was significantly lower than that among C. gattii isolates (MICs >0.5 mg/L; P < 0.001), as evaluated using the chi-square test. For most isolates of the three predominant Cryptococcus species, the MICs of new triazoles were ≤0.25 mg/L. The MICs of fluconazole and amphotericin B in the BSI/MME-causing Cryptococcus isolates collected from patients hospitalized in the Asia-Western Pacific region and Europe were significantly lower (i.e., the distributions were more leftward) than those in North America and Latin America. Ongoing monitoring of MIC data for important antifungals against cryptococcosis is crucial.

First report of environmental isolation of Cryptococcus and Cryptococcus-like yeasts from Boyacá, Colombia

The Cryptococcus genus comprises more than 100 species, of which C. neoformans and C. gattii are the leading cause of cryptococcosis. The distribution of C. gattii and C. neoformans species complexes has been extensively studied and widely reported globally. Other species such as Naganishia albida, Papiliotrema laurentii, and Papiliotrema flavescens have been reported as pathogenic yeasts. Since there are no reports of environmental isolation in the Boyacá region (Colombia), this study aimed to isolate and characterize Cryptococcus and Cryptococcus-like yeasts from pigeon feces, Eucalyptus, and olive trees distributed in the municipalities of Tunja and Ricaute Alto. The environmental data was recovered, and the isolations obtained were identified by microscopy, biochemical test, MALDI-TOF MS, URA5-RFLP, and sequencing of the ITS and LSU loci. For the 93 pigeon dropping samples collected in Tunja, 23 yielded to C. neoformans, 3 to N. globosa, 2 N. albida and 1 to P. laurentii. Of the 1188 samples collected from olive trees, 17 (1.43%) positive samples were identified as C. gattii species complex (4), C. neoformans species complex (2), P. laurentii (3), N. albida (2), N. globosa (5) and P. flavescens (1). Likewise, specimens of C. neoformans presented molecular type VNI and molecular type VNII; for C. gattii the molecular types found were VGIII and one VGIV by URA5-RFLP but VGIII by MALDI-TOF and sequencing of the ITS and LSU. Therefore, it can be concluded that the species of Cryptococcus, Naganishia and Papiliotrema genera, are present in the environment of Boyacá, and show a predilection for climate conditions that are typical of this region.

Distribution and Polymorphisms of Group I Introns in Mitochondrial Genes from Cryptococcus neoformans and Cryptococcus gattii

The species complexes Cryptococcus neoformans and Cryptococcus gattii are the causative agents of cryptococcosis. Virulence and susceptibility to antifungals may vary within each species according to the fungal genotype. Therefore, specific and easily accessible molecular markers are required to distinguish cryptic species and/or genotypes. Group I introns are potential markers for this purpose because they are polymorphic concerning their presence and sequence. Therefore, in this study, we evaluated the presence of group I introns in the mitochondrial genes cob and cox1 in different Cryptococcus isolates. Additionally, the origin, distribution, and evolution of these introns were investigated by phylogenetic analyses, including previously sequenced introns for the mtLSU gene. Approximately 80.5% of the 36 sequenced introns presented homing endonucleases, and phylogenetic analyses revealed that introns occupying the same insertion site form monophyletic clades. This suggests that they likely share a common ancestor that invaded the site prior to species divergence. There was only one case of heterologous invasion, probably through horizontal transfer to C. decagattii (VGIV genotype) from another fungal species. Our results showed that the C. neoformans complex has fewer introns compared to C. gattii. Additionally, there is significant polymorphism in the presence and size of these elements, both among and within genotypes. As a result, it is impossible to differentiate the cryptic species using a single intron. However, it was possible to differentiate among genotypes within each species complex, by combining PCRs of mtLSU and cox1 introns, for C. neoformans species, and mtLSU and cob introns for C. gattii species.

Cryptococcus gattii meningitis complicated by immune reconstitution inflammatory syndrome in an apparent immunocompetent host in Malaysia

Cryptococcosis is a systemic fungal infection caused by Cryptococcus neoformans or Cryptococcus gattii. Cryptococcus causes a wide range of diseases, ranging from asymptomatic pulmonary lesions to disseminated disease involving the central nervous system, particularly meningoencephalitis. C. gattii infection has rarely been reported in Malaysia. We present a case of C. gattii meningitis with pulmonary cryptococcosis complicated by immune reconstitution inflammatory syndrome in an apparently immunocompetent person with no prior travel history.

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Cryptococcosis is a fungal infection causing significant morbidity and mortality.

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Cryptococcus gattii can present with meningitis and pulmonary cryptococcosis.

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CSF examination is the cornerstone of diagnosis in cryptococcal meningitis.

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IRIS is a rare complication of C. gattii infection that can be treated with steroids.

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.

A Rare Case of Cryptococcus gattii Meningitis in Advanced HIV Disease, Sagittal Thrombosis, and Immune Reconstitution Syndrome, Resolved With Isavuconazonium

Cryptococcus gattii is a species that has received more recognition in the recent past as distinct from Cryptococcus neoformans. C gattii is known to cause meningeal disease in both immunocompetent and immunosuppressed hosts. Patients may be clinically asymptomatic until immunosuppressive conditions occur such as corticosteroid treatment or an HIV infection. HIV-associated cryptococcal infections are most often due to C neoformans. C gattii is found in a minority. Speciation and subtyping of Cryptococcus are not always accomplished. In many parts of the world, there is no availability for speciation of Cryptococcus. Travel history may provide a clue to the most probable species. This case demonstrates a case of C gattii meningitis with a multiplicity of complications. These include advanced HIV disease secondary to nonadherence, immune reconstitution inflammatory syndrome, and superior sagittal sinus thrombosis. The patient represented diagnostic and therapeutic dilemmas over time. Headache was the primary symptom in cryptococcal meningitis, immune reconstitution inflammatory syndrome, and superior sagittal sinus thrombosis. All are discussed in detail as potential etiologies for the primary disease. Isavuconazonium is a relatively new broad-spectrum antifungal azole that was used as salvage therapy.

Visible DNA microarray and loop-mediated isothermal amplification (LAMP) for the identification of Cryptococcus species recovered from culture medium and cerebrospinal fluid of patients with meningitis

Cryptococcal meningitis affects normal hosts and immunocompromised patients exhibiting high mortality rates. The objective of this study was to design two molecular assays, visible microarray platforms and loop-mediated isothermal amplification (LAMP), to identify Cryptococcus spp. and the species neoformans and gattii from the cerebral spinal fluid (CSF). To identify Cryptococcus and the two species, we designed two microarrays DNA platforms based on the internal transcribed spacer (ITS) region and CAP59 gene and LAMP assays specific for Cryptococcus species. The assays were tested using CSF from patients with cryptococcal meningitis. CSF from patients with cryptococcal meningitis was cultured in Sabouraud culture medium, and the Cryptococcus spp. grown in the culture medium were also tested for LAMP and microarray platforms. The results were compared to DNA sequencing of the same genetic regions. A total of 133 CSF samples were studied. Eleven CSFs were positive for Cryptococcus (9 C. neoformans and 2 C. gattii), 15 were positive for bacteria, and 107 were negative. The CAP59 platform correctly identified 73% of the CSF samples, while the ITS platform identified 45.5%. CAP59 platform correctly identified 100% of the Cryptococcus isolates, and ITS platform identified 70%. The two sets of LAMP primers correctly identified 100% of the Cryptococcus isolates. However, for CSF samples, the amplification occurred only in 55.5% of C. neoformans. The methodologies were reliable in the identification of Cryptococcus species, mainly for isolates from culture medium, and they might be applied as adjunctive tests to identify Cryptococcus species.

Diverse species in the genus Cryptococcus: Pathogens and their non-pathogenic ancestors

The genus Cryptococcus comprises of more than 30 species. It consists of clinically significant pathogenic Cryptococcus neoformans/Cryptococcus gattii species complex comprising of a minimum of seven species. These pathogens cost more than 200,000 lives annually by causing cryptococcal meningoencephalitis. The evolution of the pathogenic species from closely related non-pathogenic species of the Cryptococcus amylolentus complex is of particular importance and several advances have been made to understand their phylogenetic and genomic relationships. The current review briefly describes the sexual reproduction process followed by an individual description of the members focusing on their key attributes and virulence mechanisms of the pathogenic species. A special section on phylogenetic studies is aimed at understanding the evolutionary divergence of pathogens from non-pathogens. Recent findings from our group pertaining to parameters affecting codon usage bias in six pathogenic and three non-pathogenic ancestral species and their corroboration with existing phylogenetic reports are also included in the current review.

Genotypic and Phenotypic Stability of Mixed Primary Isolates of Cryptococcus gattii and Cryptococcus neoformans: A Comparative Analysis of Four Preservation Methods

The choice of a suitable preservation method is critical for long-term microorganisms' viability. The strains should be preserved for long periods using reliable and reproducible methods that minimize genotypic and phenotypic variations and viability losses. The methodologies are usually designed for a better performance in isolated microorganisms. However, atypical primary isolates of Cryptococcus neoformans or Cryptococcus gattii, such as mixed species or even different species of a species complex, are a challenge for long-term preservation and taxonomic review studies. The aim of this study was to evaluate which of the four preservation methods tested presented better performance in the preservation of simulated coexistence strains of C. neoformans and C. gattii. Two environmental strains, one C. gattii and one C. neoformans, were mixed in vitro to test four different preservation methods (freezing at -20°C, -80°C, -196°C, and freeze-drying). The colony-forming units from each preservation method were evaluated, and colonies were randomly selected and cultivated in canavanine glycine bromothymol blue (CGB) agar to evaluate the amounts of CGB-positive (C. gattii) and CGB-negative (C. neoformans) colonies resulting from each preservation method after 1 week, 15 days, 1 month, 6 months, and 1 year. According to our results, cryopreservation at -20°C demonstrated was preferable for C. neoformans species, and further studies after long-term storage are necessary. Recovery of yeast cells after freeze-dried preservation in skim milk is better for both species. Ultrafreezing methods evaluated (-80°C and -196°C) also showed better results in the maintenance of C. gattii. Freeze-drying should be preferred for the maintenance of multilineage isolates from the C. neoformans and C. gattii species complexes.

On the Emergence of Cryptococcus gattii in the Pacific Northwest: Ballast Tanks, Tsunamis, and Black Swans

The appearance of Cryptococcus gattii in the North American Pacific Northwest (PNW) in 1999 was an unexpected and is still an unexplained event. Recent phylogenomic analyses strongly suggest that this pathogenic fungus arrived in the PNW approximately 7 to 9 decades ago. In this paper, we theorize that the ancestors of the PNW C. gattii clones arrived in the area by shipborne transport, possibly in contaminated ballast, and established themselves in coastal waters early in the 20th century. In 1964, a tsunami flooded local coastal regions, transporting C. gattii to land. The occurrence of cryptococcosis in animals and humans 3 decades later suggests that adaptation to local environs took time, possibly requiring an increase in virulence and further dispersal. Tsunamis as a mechanism for the seeding of land with pathogenic waterborne microbes may have important implications for our understanding of how infectious diseases emerge in certain regions. This hypothesis suggests experimental work for its validation or refutation.

Cryptococcus neoformans and gattii promote DNA damage in human peripheral blood mononuclear cells

Cryptococcosis, a systemic mycosis capable of disseminating to the central nervous system with frequent lethal effects, is caused by the species Cryptococus neoformans and Cryptococcus gattii. Several infectious agents such as virus, bacteria, and parasites may be associated to DNA damage and carcinogenesis in humans. Products of the oxidative metabolism, such as NO, produced as a host defense mechanism to destroy these pathogens, have been implicated in this damage process, due to excessive production related to an established chronic inflammatory response. Here, we investigated whether C. neoformans and /or C. gattii can cause DNA damage in human peripheral blood mononuclear cells (PBMCs) and whether this process is related to NO levels produced by PBMCs. We found that both species are equally able to induce genotoxicity in PBMCs. However, an association between DNA damage and high NO levels was only detected in relation to C. gattii. The results point to the possibility that patients with cryptococcosis are more susceptible to the development of other diseases.

Searching for clues for eighteen years: Deciphering the ecological determinants of Cryptococcus gattii on Vancouver Island, British Columbia

Cryptococcus gattii emerged on Vancouver Island in 1999 for unknown reasons, causing human and animal fatalities and illness. The apparent emergence of this fungus in another temperate area, this time in the Pacific Northwest, suggests the fungus may have expanded its ecological niche. Yet studies that directly examine the potential roles of climatic and land use changes on C. gattii are still lacking. We aim to summarize the existing global literature on the ecology of C. gattii, with particular focus on the gap in knowledge surrounding the potential effects of climatic and land use changes. We systematically reviewed English peer-reviewed literature on the ecological determinants of C. gattii. We included studies published from January 1970 through June 2016 and identified 56 relevant studies for our review. We identified environmental isolations of C. gattii from 18 countries, spanning 72 separate regions across six continents. Fifty-three tree species were associated with C. gattii, spanning 10 climate classifications and 36 terrestrial ecoregions. No studies directly tested the potential effects of climatic changes (including climatic oscillations and global climate change) on C. gattii, while only one study directly assessed those of land use change. To improve model predictions of current and future distributions of C. gattii, more focus is needed on the potential effects of climatic and land use changes to help decrease the public health risk. The apparent emergence of C. gattii in British Columbia is also an opportunity to explore the factors behind emerging infectious diseases in Canada and elsewhere.

Hybrids and hybridization in the Cryptococcus neoformans and Cryptococcus gattii species complexes

The basidiomycetous yeasts of the Cryptococcus neoformans and Cryptococcus gattii species complexes (CNSC and CGSC respectively) are the causative agents of cryptococcosis, a set of life-threatening diseases affecting the central nervous system, lungs, skin, and other body sites of humans and other mammals. Both the CNSC and CGSC can be subdivided into varieties, serotypes, molecular types, and lineages based on structural variations, molecular characteristics and genetic sequences. Hybridization between the haploid lineages within and between the two species complexes is known to occur in natural and clinical settings, giving rise to intraspecific and interspecific diploid/aneuploid hybrid strains. Since their initial discovery in 1977, cryptococcal hybrids have been increasingly discovered in both clinical and environmental settings with over 30% of all cryptococcal infections in some regions of Europe being caused by hybrid strains. This review summarizes the major findings to date on cryptococcal hybrids, including their possible origins, prevalence, genomic profiles and phenotypic characteristics. Our analyses suggest that CNSC and CGSC can be an excellent model system for studying fungal hybridization.

The effects of environmental and genetic factors on the germination of basidiospores in the Cryptococcus gattii species complex

Natural and artificial hybridization has been frequently reported among divergent lineages within and between the two closely related human pathogenic fungi Cryptococcus gattii species complex and Cryptococcus neoformans species complex. However, the biological effects of such hybridization are not well known. Here we used five strains of the C. neoformans species complex and twelve strains of the C. gattii species complex to investigate the potential effects of selected environmental and genetic factors on the germination of their basidiospores from 29 crosses. We found that the germination rates varied widely among crosses and environmental conditions, ranging from 0% to 98%. Overall, the two examined media showed relatively little difference on spore germination while temperature effects were notable, with the high temperature (37 °C) having an overall deleterious effect on spore germination. Within the C. gattii species complex, one intra-lineage VGIII × VGIII cross had the highest germination rates among all crosses at all six tested environmental conditions. Our analyses indicate significant genetic, environmental, and genotype-environment interaction effects on the germination of basidiospores within the C. gattii species complex.

Evolutionarily Conserved and Divergent Roles of Unfolded Protein Response (UPR) in the Pathogenic Cryptococcus Species Complex

The unfolded protein response (UPR) pathway, consisting of the evolutionarily conserved Ire1 kinase/endonuclease and the bZIP transcription factor Hxl1, is critical for the pathogenicity of Cryptococcus neoformans; however, its role remains unknown in other pathogenic Cryptococcus species. Here, we investigated the role of the UPR pathway in C. deuterogattii, which causes pneumonia and systemic cryptococcosis, even in immunocompetent individuals. In response to ER stress, C. deuterogattii Ire1 triggers unconventional splicing of HXL1 to induce the expression of UPR target genes such as KAR2, DER1, ALG7, and ERG29. Furthermore, C. deuterogattii Ire1 is required for growth at mammalian body temperature, similar to C. neoformans Ire1. However, deletion of HXL1 does not significantly affect the growth of C. deuterogattii at 37 °C, which is in contrast to the indispensable role of HXL1 in the growth of C. neoformans at 37 °C. Nevertheless, both C. deuterogattii ire1Δ and hxl1Δ mutants are avirulent in a murine model of systemic cryptococcosis, suggesting that a non-thermotolerance phenotypic trait also contributes to the role of the UPR pathway in the virulence of pathogenic Cryptococcus species. In conclusion, the UPR pathway plays redundant and distinct roles in the virulence of members of the pathogenic Cryptococcus species complex.

Genomic Understanding of an Infectious Brain Disease from the Desert

Rhinocladiella mackenziei accounts for the majority of fungal brain infections in the Middle East, and is restricted to the arid climate zone between Saudi Arabia and Pakistan. Neurotropic dissemination caused by this fungus has been reported in immunocompromised, but also immunocompetent individuals. If untreated, the infection is fatal. Outside of humans, the environmental niche of R. mackenziei is unknown, and the fungus has been only cultured from brain biopsies. In this paper, we describe the whole-genome resequencing of two R. mackenziei strains from patients in Saudi Arabia and Qatar. We assessed intraspecies variation and genetic signatures to uncover the genomic basis of the pathogenesis, and potential niche adaptations. We found that the duplicated genes (paralogs) are more susceptible to accumulating significant mutations. Comparative genomics with other filamentous ascomycetes revealed a diverse arsenal of genes likely engaged in pathogenicity, such as the degradation of aromatic compounds and iron acquisition. In addition, intracellular accumulation of trehalose and choline suggests possible adaptations to the conditions of an arid climate region. Specifically, protein family contractions were found, including short-chain dehydrogenase/reductase SDR, the cytochrome P450 (CYP) (E-class), and the G-protein β WD-40 repeat. Gene composition and metabolic potential indicate extremotolerance and hydrocarbon assimilation, suggesting a possible environmental habitat of oil-polluted desert soil.

Polymorphism in Mitochondrial Group I Introns among Cryptococcus neoformans and Cryptococcus gattii Genotypes and Its Association with Drug Susceptibility

Cryptococcosis, one of the most important systemic mycosis in the world, is caused by different genotypes of Cryptococcus neoformans and Cryptococcus gattii, which differ in their ecology, epidemiology, and antifungal susceptibility. Therefore, the search for new molecular markers for genotyping, pathogenicity and drug susceptibility is necessary. Group I introns fulfill the requisites for such task because (i) they are polymorphic sequences; (ii) their self-splicing is inhibited by some drugs; and (iii) their correct splicing under parasitic conditions is indispensable for pathogen survival. Here, we investigated the presence of group I introns in the mitochondrial LSU rRNA gene in 77 Cryptococcus isolates and its possible relation to drug susceptibility. Sequencing revealed two new introns in the LSU rRNA gene. All the introns showed high sequence similarity to other mitochondrial introns from distinct fungi, supporting the hypothesis of an ancient non-allelic invasion. Intron presence was statistically associated with those genotypes reported to be less pathogenic (p < 0.001). Further virulence assays are needed to confirm this finding. In addition, in vitro antifungal tests indicated that the presence of LSU rRNA introns may influence the minimum inhibitory concentration (MIC) of amphotericin B and 5-fluorocytosine. These findings point to group I introns in the mitochondrial genome of Cryptococcus as potential molecular markers for antifungal resistance, as well as therapeutic targets.

Cryptococcal meningitis in AIDS

Cryptococcal meningitis remains a significant cause of morbidity and mortality amongst patients living with human immunodeficiency virus (HIV). The prevalence in the developed world has decreased as HIV is being diagnosed earlier, but is still significant, and the prevalence in resource-limited settings is exceedingly high. The presenting symptoms usually include a headache, fever, and, less often, cranial nerve abnormalities. Space-occupying lesions do occur, but are rare. Once diagnosed, patients should be treated with a combination of amphotericin and flucytosine, with step-down therapy to fluconazole for a minimum of a year, or until the CD4 count is above 100 cells/μL, whichever is longer. In the acute phase of treatment increased opening pressure is common, which should be managed aggressively with frequent lumbar punctures, or through neurosurgical interventions (lumbar drains, ventriculoperitoneal shunts) if those fail. Antiretrovirals should be delayed at least 2 weeks, but maybe as many as 10 weeks, after initiation of antifungal therapy in order to prevent clinical or subclinical immune reconstitution inflammatory syndrome (IRIS), which may lead to increased mortality. However, if IRIS does develop, there is no role for antiretroviral interruption, and the condition should be managed supportively by use of anti-inflammatories and aggressive management of elevated opening pressure, if present. Steroids should be administered for specific indications only (IRIS or cryptococcoma with cerebral edema and risk of herniation) as routine use of steroids increases mortality in cryptococcal meningitis.

In vitro and in vivo antifungal activities of T-2307, a novel arylamidine, against Cryptococcus gattii: an emerging fungal pathogen

Objectives

T-2307, a novel arylamidine, exhibits potent broad-spectrum activities against the majority of fungal pathogens. In this study, the antifungal activity of T-2307 against Cryptococcus gattii was evaluated in comparison with those of amphotericin B, fluconazole and voriconazole in vitro and in vivo .

Methods

The MICs for 15 clinical isolates were determined according to CLSI guidelines and time-kill studies were performed using C. gattii YF2784. In a murine model for intranasal pulmonary infection caused by C. gattii YF2784, the test compounds were administered once daily for 7 days from 2 h or 14 days post-infection. The viable counts in the lungs and brain were determined at 21 days post-infection.

Results

The MIC range, MIC 50 , MIC 90 and geometric mean MIC of T-2307 were 0.0078-0.0625, 0.0313, 0.0625 and 0.0394 mg/L, respectively. The MIC of T-2307 was significantly lower than those of fluconazole, voriconazole and amphotericin B. T-2307 showed concentration-dependent fungicidal activity at 4 times the MIC or higher. Administration of T-2307 at 2 mg/kg/day, amphotericin B at 1 mg/kg/day and fluconazole at 160 mg/kg/day from 2 h post-infection significantly reduced viable counts in the lungs and brain. However, when the administration was started 14 days post-infection, only T-2307 significantly reduced the viable counts in both the lungs and the brain at 1 mg/kg/day.

Conclusions

T-2307 shows excellent in vitro and in vivo antifungal activities against C. gattii and would be a promising new candidate for the treatment of cryptococcosis.

Epidemiology and trends of cryptococcosis in the United States from 2000 to 2007: A population-based study

Cryptococcal disease, caused by Cryptococcus neoformans and Cryptococcus gattii, is associated with significant morbidity and mortality but limited data exist on its incidence and impact. A study utilizing the Nationwide Inpatient Sample from 2000 to 2007 to examine the epidemiology and impact of cryptococcal disease in the United States was undertaken. The International Classification of Diseases 9th Version code was used to identify hospital discharges with diagnosis of Cryptococcus (117.5). Our primary outcome was the incidence rate of cryptococcal admissions. The impact of AIDS, age, and sex on hospitalization rates, mortality, and costs was assessed. The results showed that a total of 10,077 hospitalizations for cryptococcosis occurred corresponding to a weighted estimate of 49,010 cases. The median age was 43 years (interquartile range 34-54), and 26% were female. Approximately 64% of cases occurred in persons with AIDS. Although rates declined overall, age-adjusted rates were significantly higher in males with AIDS than in uninfected persons (p < 0.001). The mortality rate decreased but was greater in HIV-uninfected versus infected cohorts (12% versus 10%, p < 0.001). Conversely, hospital costs were greater in persons with AIDS ($40,671 versus $40,096, p=0.02). Although cryptococcal disease rates are decreasing over time, the associated mortality and costs remain concerning.

Cryptococcus gattii in an Immunocompetent Patient in the Southeastern United States

Cryptococcal infections are seen throughout the United States in both immunocompromised and immunocompetent patients. The most common form is C. neoformans. In the Northwestern United States, C. gattii has received considerable attention secondary to increased virulence resulting in significant morbidity and mortality. There are no cases in the extant literature describing a patient with C. gattii requiring neurosurgical intervention in Alabama. A middle-aged immunocompetent male with no recent travel or identifiable exposure presented with meningitis secondary to C. gattii. The patient underwent 12 lumbar punctures and a ventriculoperitoneal shunt and required 83 days of inpatient therapy with 5-flucytosine and amphotericin B. The patient was found to have multiple intracranial lesions and a large intramedullary spinal cryptococcoma within his conus. Following an almost 3-month hospitalization the patient required treatment with oral voriconazole for one year. In the United States meningitis caused by C. gattii infection is not isolated to the Northwestern region.

ANTIFUNGAL SUSCEPTIBILITY TESTING AND GENOTYPING CHARACTERIZATION OF Cryptococcus neoformans AND gattii ISOLATES FROM HIV-INFECTED PATIENTS OF RIBEIRÃO PRETO, SÃO PAULO, BRAZIL

Cryptococcosis is a leading invasive fungal infection in immunocompromised patients. Considering the high prevalence and severity of these infections in immunocompromised patients attended at HC-FMRP-USP, the present research aimed to characterize the clinical isolates of Cryptococcus strains by biochemical and molecular methods and evaluate antifungal susceptibility of clinical isolates. Fifty isolates from 32 HIV-positive patients were obtained at HC-FMRP-USP. Most of the isolates (78.1%) were identified as C. neoformans, and 100% of C. neoformans and C. gattii strains were susceptible to amphotericin B, ketoconazole and fluconazole. All isolates were classified as serotype A (grubbii variety) by PCR and most of them were characterized in mating type MATa. PCR analysis of specific M13 microsatellite sequence revealed that VNI type was predominant among C. neoformans, while VGII was predominant among C. gattii. The strains did not show a significant resistance to the antifungals tested, and Canavanine-Glycine-Bromthymol Blue Agar (CGB) proved to be a reliable test presenting a good correlation with the molecular characterization. C. neoformans isolated from disseminated infections in the same patient showed molecular identity when different anatomical sites were compared; besides, the studied strains did not present a significant increase in resistance to antifungal agents. In addition, the homogeneity of the molecular types and detection of the mating types suggested a low possibility of crossing among the strains.

Cryptococcus gattii Type VGIIa Infection in Harbor Seals ( Phoca vitulina ) in British Columbia, Canada

Cryptococcosis has been reported in marine mammals in the northeastern Pacific with increasing frequency in the last 15 yr. Although a variety of cetaceans have been diagnosed with cryptococcosis, Cryptococcus gattii has not been reported in pinnipeds. We document C. gattii VGIIa in a harbor seal ( Phoca vitulina ) pup and in an unrelated adult. Both animals were presented to Vancouver Aquarium's Marine Mammal Rescue Centre (VAMMRC) with generalized weakness, dehydration, respiratory compromise, minimally responsive mentation, and suboptimal body condition. Necropsy and histopathology findings were consistent in both animals and featured generalized lymphadenopathy, bronchopneumonia, and meningoencephalitis with intralesional yeast and fungemia. Cryptococcal serum antigen titers were ≥1,024 in both animals. Fungal culture of lung and lymph nodes confirmed C. gattii . Exposure was likely via inhalation prior to presentation to VAMMRC, and C. gattii infection was the proximate cause of death. This report expands the range of susceptible host species as C. gattii continues to emerge as a pathogen of concern in marine mammals in the northeastern Pacific.

Deubiquitinase Ubp5 Is Required for the Growth and Pathogenicity of Cryptococcus gattii

Cryptococcus gattii is a resurgent fungal pathogen that primarily infects immunocompetent hosts. Thus, it poses an increasingly significant impact on global public health; however, the mechanisms underlying its pathogenesis remain largely unknown. We conducted a detailed characterization of the deubiquitinase Ubp5 in the biology and virulence of C. gattii using the hypervirulent strain R265, and defined its properties as either distinctive or shared with C. neoformans. Deletion of the C. gattii Ubp5 protein by site-directed disruption resulted in a severe growth defect under both normal and stressful conditions (such as high temperature, high salt, cell wall damaging agents, and antifungal agents), similar to the effects observed in C. neoformans. However, unlike C. neoformans, the C. gattii ubp5Δ mutant displayed a slight enhancement of capsule and melanin production, indicating the evolutionary convergence and divergence of Ubp5 between these two sibling species. Attenuated virulence of the Cg-ubp5Δ mutant was not solely due to its reduced thermotolerance at 37°C, as shown in both worm and mouse survival assays. In addition, the assessment of fungal burden in mammalian organs further indicated that Ubp5 was required for C. gattii pulmonary survival and, consequently, extrapulmonary dissemination. Taken together, our work highlights the importance of deubiquitinase Ubp5 in the virulence composite of both pathogenic cryptococcal species, and it facilitates a better understanding of C. gattii virulence mechanisms.

Virulence of Cryptococcus sp. Biofilms In Vitro and In Vivo using Galleria mellonella as an Alternative Model

Cryptococcus neoformans and C. gattii are fungal pathogens that are most commonly found in infections of the central nervous system, which cause life-threatening meningoencephalitis and can grow as a biofilm. Biofilms are structures conferring protection and resistance of microorganism to the antifungal drugs. This study compared the virulence of planktonic and biofilm cells of C. neoformans and C. gattii in Galleria mellonella model, as well as, the quantification of gene transcripts LAC1, URE1, and CAP59 by real time PCR. All three of the genes showed significantly increased expressions in the biofilm conditions for two species of Cryptococcus, when compared to planktonic cells. C. neoformans and C. gattii cells in the biofilm forms were more virulent than the planktonic cells in G. mellonella. This suggests that the biofilm conditions may contribute to the virulence profile. Our results contribute to a better understanding of the agents of cryptococcosis in the host-yeast aspects of the interaction.

Refractory and/or Relapsing Cryptococcosis Associated with Acquired Immune Deficiency Syndrome: Clinical Features, Genotype, and Virulence Factors of Cryptococcus spp. Isolates

Refractory and relapsing crytocococcosis in acquired immune deficiency syndrome (AIDS) patients have a poor prognosis. The risk factors for this complicated infection course were evaluated by comparing refractory and/or relapsing cryptococcosis in human immunodeficiency virus-coinfected patients (cohort 1) with another group of AIDS patients who adequately responded to antifungals (cohort 2). Except for one isolate of Cryptococcus gattii from a cohort 2 case, all other isolates were identified as Cryptococcus neoformans var. grubii, sex type α, genotype VNI, including Cryptococcus reisolated from the relapse or in the refractory state. No differences were observed with respect to Cryptococcus capsule size and in the melanin and phospholipase production. The cohort 1 patients presented higher prevalence of cryptococcemia, cerebral dissemination, chronic liver disease, and leucopenia, and have increased death rate. Apparently, the refractory and/or relapsing cryptococcosis in the AIDS patients were more related to the host and the extent of the infection than to the fungal characteristics.

Host immunity to Cryptococcus neoformans

Cryptococcosis is caused by the fungal genus Cryptococcus. Cryptococcosis, predominantly meningoencephalitis, emerged with the HIV pandemic, primarily afflicting HIV-infected patients with profound T-cell deficiency. Where in use, combination antiretroviral therapy has markedly reduced the incidence of and risk for disease, but cryptococcosis continues to afflict those without access to therapy, particularly in sub-Saharan Africa and Asia. However, cryptococcosis also occurs in solid organ transplant recipients and patients with other immunodeficiencies as well as those with no known immunodeficiency. This article reviews innate and adaptive immune responses to C. neoformans, with an emphasis on recent studies on the role of B cells, natural IgM and Fc gamma receptor polymorphisms in resistance to cryptococcosis.

What makes Cryptococcus gattii a pathogen?

Cryptococcosis is an invasive fungal infection of humans and other animals, typically caused by the species Cryptococcus neoformans in patients with impaired immunity. However, there is growing recognition of the importance of the related species C. gattii in causing infections in apparently immunocompetent individuals. In particular, an ongoing outbreak of cryptococcal disease in the Pacific Northwest region, which started in 1999, has driven an intense research effort into this previously neglected pathogen. Here, we discuss some of the recent discoveries in this organism from the Pacific Northwest region and highlight areas for future investigation.

Is Cryptococcus gattii a Primary Pathogen?

The two etiologic agents of cryptococcal meningoencephalitis, Cryptococcus neoformans and C. gattii, have been commonly designated as either an opportunistic pathogen for the first species or as a primary pathogen for the second species. Such a distinction has been based on epidemiological findings that the majority of patients presenting meningoencephalitis caused by C. neoformans are immunocompromised while C. gattii infection has been reported more often in immunocompetent patients. A recent report, however, showed that GM-CSF (granulocyte-macrophage colony-stimulating factor) neutralizing antibodies were prevalent in the plasma of "apparently immunocompetent" C. gattii patients with meningoencephalitis. Because GM-CSF is essential for differentiation of monocytes to macrophages and modulating the immune response, it is not surprising that the lack of GM-CSF function predisposes otherwise healthy individuals to infection via inhalation of environmental pathogens such as C. gattii. Since the test for anti-GM-CSF autoantibodies is not included in routine immunological profiling at most hospitals, healthy patients with GM-CSF neutralizing antibodies are usually categorized as immunocompetent. It is likely that a comprehensive immunological evaluation of patients with C. gattii meningoencephalitis, who had been diagnosed as immunocompetent, would reveal a majority of them had hidden immune dysfunction. This paper reviews the relationship between GM-CSF neutralizing antibodies and the risk for C. gattii infection with CNS involvement.

Cryptococcus gattii infections

Understanding of the taxonomy and phylogeny of Cryptococcus gattii has been advanced by modern molecular techniques. C. gattii probably diverged from Cryptococcus neoformans between 16 million and 160 million years ago, depending on the dating methods applied, and maintains diversity by recombining in nature. South America is the likely source of the virulent C. gattii VGII molecular types that have emerged in North America. C. gattii shares major virulence determinants with C. neoformans, although genomic and transcriptomic studies revealed that despite similar genomes, the VGIIa and VGIIb subtypes employ very different transcriptional circuits and manifest differences in virulence phenotypes. Preliminary evidence suggests that C. gattii VGII causes severe lung disease and death without dissemination, whereas C. neoformans disseminates readily to the central nervous system (CNS) and causes death from meningoencephalitis. Overall, currently available data indicate that the C. gattii VGI, VGII, and VGIII molecular types more commonly affect nonimmunocompromised hosts, in contrast to VGIV. New, rapid, cheap diagnostic tests and imaging modalities are assisting early diagnosis and enabling better outcomes of cerebral cryptococcosis. Complications of CNS infection include increased intracranial pressure, severe neurological sequelae, and development of immune reconstitution syndrome, although the mortality rate is low. C. gattii VGII isolates may exhibit higher fluconazole MICs than other genotypes. Optimal therapeutic regimens are yet to be determined; in most cases, initial therapy with amphotericin B and 5-flucytosine is recommended.

The response of trypanosomes and other eukaryotes to ER stress and the spliced leader RNA silencing (SLS) pathway in Trypanosoma brucei

The unfolded protein response (UPR) is induced when the quality control machinery of the cell is overloaded with unfolded proteins or when one of the functions of the endoplasmic reticulum (ER) is perturbed. Here, I describe UPR in yeast and mammals, and compare it to what we know about pathogenic fungi and the parasitic protozoans from the order kinetoplastida, focusing on the novel pathway the spliced leader silencing (SLS) in Trypanosoma brucei. Trypanosomes lack conventional transcription regulation, and thus, lack most of the UPR machinery present in other eukaryotes. Trypanosome genes are transcribed in polycistronic units that are processed by trans-splicing and polyadenylation. In trans-splicing, which is essential for processing of each mRNA, an exon known as the spliced leader (SL) is added to all mRNAs from a small RNA, the SL RNA. Under severe ER stress, T. brucei elicits the SLS pathway. In SLS, the transcription of the SL RNA gene is extinguished, and the entire transcription complex dissociates from the SL RNA promoter. Induction of SLS is mediated by an ER-associated kinase (PK3) that migrates to the nucleus, where it phosphorylates the TATA-binding protein (TRF4), leading shut-off of SL RNA transcription. As a result, trans-splicing is inhibited and the parasites activate a programmed cell death (PCD) pathway. Despite the ability to sense the ER stress, the different eukaryotes, especially unicellular parasites and pathogenic fungi, developed a variety of unique and different ways to sense and adjust to this stress in a manner different from their host.

Identification and properties of plasma membrane azole efflux pumps from the pathogenic fungi Cryptococcus gattii and Cryptococcus neoformans

OBJECTIVES

Cryptococcus gattii from the North American Northwest (NW) have higher azole MICs than do non-NW C. gattii or Cryptococcus neoformans. Since mechanisms of azole resistance in C. gattii are not known, we identified C. gattii and C. neoformans plasma membrane azole efflux pumps and characterized their properties.

METHODS

The C. gattii R265 genome was searched for orthologues of known fungal azole efflux genes, expression of candidate genes was assessed by RT-PCR and the expressed genes' cDNAs were cloned and expressed in Saccharomyces cerevisiae. Azole MICs and intracellular [(3)H]fluconazole were measured in C. gattii and C. neoformans and in S. cerevisiae expressing each cDNA of interest, as was [(3)H]fluconazole uptake by post-Golgi vesicles (PGVs) isolated from S. cerevisiae sec6-4 mutants expressing each cDNA of interest.

RESULTS

Intracellular [(3)H]fluconazole concentrations were inversely correlated with fluconazole MICs only in 25 NW C. gattii strains. S. cerevisiae expressing three C. gattii cDNAs (encoded by orthologues of C. neoformans AFR1 and MDR1 and the previously unstudied gene AFR2) and their C. neoformans counterparts had higher azole MICs and lower intracellular [(3)H]fluconazole concentrations than did empty-vector controls. PGVs from S. cerevisiae expressing all six Cryptococcus cDNAs also accumulated more [(3)H]fluconazole than did controls, and [(3)H]fluconazole transport by all six transporters of interest was ATP dependent and was inhibited by excess unlabelled fluconazole, voriconazole, itraconazole and posaconazole.

CONCLUSIONS

We conclude that C. gattii and C. neoformans AFR1, MDR1 and AFR2 encode ABC transporters that pump multiple azoles out of S. cerevisiae cells, thereby causing azole resistance.

Carbon dioxide is a powerful inducer of monokaryotic hyphae and spore development in Cryptococcus gattii and carbonic anhydrase activity is dispensable in this dimorphic transition

Cryptococcus gattii is unique among human pathogenic fungi with specialized ecological niche on trees. Since leaves concentrate CO₂, we investigated the role of this gaseous molecule in C. gattii biology and virulence. We focused on the genetic analyses of β-carbonic anhydrase (β-CA) encoded by C. gattii CAN1 and CAN2 as later is critical for CO₂ sensing in a closely related pathogen C. neoformans. High CO₂ conditions induced robust development of monokaryotic hyphae and spores in C. gattii. Conversely, high CO₂ completely repressed hyphae development in sexual mating. Both CAN1 and CAN2 were dispensable for CO₂ induced morphogenetic transitions. However, C. gattii CAN2 was essential for growth in ambient air similar to its reported role in C. neoformans. Both can1 and can2 mutants retained full pathogenic potential in vitro and in vivo. These results provide insight into C. gattii adaptation for arboreal growth and production of infectious propagules by β-CA independent mechanism(s).

Long-term survival of Cryptococcus neoformans and Cryptococcus gattii in stored environmental samples from Colombia

BACKGROUND

Both Cryptococcus neoformans and Cryptococcus gattii have been isolated from a variety of environmental sources in Colombia.

AIM

To determine the viability of C. neoformans/C. gattii isolates in stored soil samples, filtrates and bird droppings from which these yeasts were previously recovered.

METHODS

A total of 964 samples collected between 2003 and 2009, and kept at room temperature were processed. From them, 653 samples were from trees decaying wood, 274 from soil filtrates and 37 from bird droppings. When C. neoformans or C. gattii were recovered, the molecular type of each isolate was established by PCR fingerprinting using the single primer (GTG)5.

RESULTS

Among the processed samples, 161 isolates were recovered. From those, 81 (50.3%) corresponded to C. gattii recovered from decaying wood of Eucalyptus spp., Corymbia ficifolia, Terminalia catappa and Ficus spp. trees, and 80 (49.7%) corresponded to C. neoformans recovered from Ficus spp. and eucalyptus trees, as well as from bird droppings. The most prevalent molecular type among the C. gattii and C. neoformans isolates was VGII and VNI, respectively.

CONCLUSIONS

The re-isolation of C. neoformans/C. gattii from 10-year stored samples suggests that these yeasts are able to keep viable in naturally colonized samples.

Epidemiology of Cryptococcus and cryptococcosis in China

Cryptococcosis is a significant invasive fungal infection with noteworthy morbidity and mortality, primarily caused by Cryptococcus neoformans and Cryptococcus gattii. In China, C. neoformans var. grubii (especially molecular type VNI) is the most common variety in the environment and responsible for the majority of cryptococcal infections. C. gattii infections are quite rare in China and the primary molecular type is VGI, which is closely related to C. gattii isolates in Australia. Interestingly, the majority of cryptococcosis in China were reported in the HIV-uninfected patients (especially immunocompetent hosts). This unique phenomenon may be attributed to multiple polymorphisms in the genes encoding mannose-binding lectin (MBL) and Fc-gamma receptor 2B (FCGR2B) in the Han population, the major ethnic group in China. Compared to immunocompromised patients, immunocompetent patients with cryptococcal meningitis often presented with more intense inflammatory responses and more severe neurological complications, but less fungal burdens and disseminated infection. The overall prognosis, which is independently associated with amphotericin B-based initial therapy, is similar between immunocompetent and immunocompromised patients. In addition, intrathecal administration of amphotericin B has been proved to be an effective adjunctive treatment for cryptococcosis in China.

Molecular identity and prevalence of Cryptococcus spp. nasal carriage in asymptomatic feral cats in Italy

Cryptococcosis is a life-threatening fungal disease that infects humans and animals worldwide. Inhalation of fungal particles from an environmental source can cause primary infection of the respiratory system. As animals can be considered a sentinel for human diseases, the aim of this study was to determine the prevalence and molecular identity of Cryptococcus spp. in the nasal cavity of feral cats. Cats from 162 urban and rural feral cat colonies were sampled over 3 years. Of 766 cats from which nasal swabs were obtained, Cryptococcus spp. were recovered from 95 (12.6%), including 37 C. magnus (4.8%), 16 C. albidus (2.0%), 15 C. carnescens (1.9%), 12 C. neoformans (1.6%), as well as C. oeirensis (n = 3), C. victoriae (n = 3), C. albidosimilis (n = 2), Filobasidium globisporum (n = 2), C. adeliensis (n = 1), C. flavescens (n = 1), C. dimnae (n = 1), C. saitoi (n = 1), and C. wieringae (n = 1) with prevalence <1%. Thirteen Cryptococcus species were identified by polymerase chain reaction and sequencing of internal transcribed spacer amplicons. Statistical analysis did not identify any predisposing factors that contributed to nasal colonization (eg, sex, age, season, or habitat). Results suggest that asymptomatic feral cats may carry C. neoformans and other Cryptococcus species in their sinonasal cavity. Genotyping of the specific cryptococcal isolates provides a better understanding of the epidemiology of these yeasts.

Clinical and microbiological characteristics of cryptococcosis in Singapore: predominance of Cryptococcus neoformans compared with Cryptococcus gattii

OBJECTIVES

To describe the clinical features, treatments, outcomes, and subtype prevalence of cryptococcosis in Singapore.

METHODS

All patients with laboratory confirmed cryptococcal infections admitted from 1999 to 2007 to a teaching hospital in Singapore were reviewed retrospectively. Identification and molecular types of Cryptococcus neoformans variants and Cryptococcus gattii were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Serotypes were inferred with a multiplex PCR method.

RESULTS

Of 62 patients with cryptococcosis, C. neoformans var. grubii was the predominant subtype (in 95%), affecting mainly immunocompromised hosts (91%) with HIV infection (80%). Patients with HIV were younger (median age 36.5 vs. 49.5 years, p=0.006) and less likely to present with an altered mental status (14% vs. 50%, p=0.013). In contrast, delayed treatment (median 7 days vs. 2 days, p=0.03), pulmonary involvement (58% vs. 14%, p=0.03), and initial treatment with fluconazole (25% vs. 2%, p=0.02) were more common in HIV-negative patients. C. gattii was uncommon, affecting only three patients, all of whom were immunocompetent and had disseminated disease with pulmonary and neurological involvement. All C. gattii were RFLP type VG II, serotype B and all C. neoformans var. grubii were RFLP type VN I, serotype A, except for one that was RFLP type VN II.

CONCLUSION

C. neoformans var. grubii, subtype VN I, was the predominant subtype in Singapore, infecting younger, mainly immunocompromised hosts with HIV. C. gattii was uncommon, causing pulmonary manifestations in older, immunocompetent patients and were RFLP type VG II.

Phenotypic differences of Cryptococcus molecular types and their implications for virulence in a Drosophila model of infection

Compared to Cryptococcus neoformans, little is known about the virulence of the molecular types in Cryptococcus gattii. We compared in vitro virulence factor production and survival data using a Drosophila model of infection to further characterize the phenotypic features of different cryptococcal molecular types. Forty-nine different isolates were inoculated into wild-type flies and followed for survival. In vitro, isolates were assessed for growth at 30 and 37°C, melanin production, capsule size, resistance to H(2)O(2), and antifungal susceptibility. A mediator model was used to assess molecular type and virulence characteristics as predictors of survival in the fly model. VGIII was the most virulent molecular type in flies (P < 0.001). At 30°C, VGIII isolates grew most rapidly; at 37°C, VNI isolates grew best. C. gattii capsules were larger than those of C. neoformans (P < 0.001). Mediator model analysis found a strong correlation of Drosophila survival with molecular type and with growth at 30°C. We found molecular-type-specific differences in C. gattii in growth at different temperatures, melanin production, capsule size, ability to resist hydrogen peroxide, and antifungal susceptibility, while growth at 30°C and the VGIII molecular type were strongly associated with virulence in a Drosophila model of infection.

Identification of the major molecular types of Cryptococcus neoformans and C. gattii by Hyperbranched rolling circle amplification

The agents of cryptococcosis C. neoformans and C. gattii are important agents of meningoencephalitis in immunocompromised and immunocompetent hosts, respectively. They are grouped into eight major molecular types, VNI-VNIV for C. neoformans and VGI-VGIV for C. gattii. These major molecular types differ in their host range, epidemiology, antifungal susceptibility and geographic distribution. To enable a rapid identification of the major molecular types and potential hybrids within the two species specific probes based on the PLB1 gene in combination with hyperbranched rolling circle amplification (HRCA) were developed. HRCA was applied to 76 cryptococcal strains, 10 strains each representing the 7 haploid major molecular types, 4 VNIII hybrid strains and 2 inter-species hybrid strains. All strains were correctly identified to the major molecular type and or hybrid type using HRCA alone. To increase the sensitivity a semi-nested PCR step was developed, which will enable the identification of the molecular types/hybrids directly from clinical samples, harboring a low copy number of DNA (40 copies). Thus, HRCA based on the PLB1 locus alone and in combination with a semi-nested PCR showed to be a specific and sensitive methodology, with a great potential to be used on clinical specimens for the direct diagnosis of the agents of cryptococcosis, including hybrid strains, enabling a rapid and patient tailored treatment choice of this disease.

Cryptococcus gattii infections in multiple states outside the US Pacific Northwest

Clonal VGII subtypes (outbreak strains) of Cryptococcus gattii have caused an outbreak in the US Pacific Northwest since 2004. Outbreak-associated infections occur equally in male and female patients (median age 56 years) and usually cause pulmonary disease in persons with underlying medical conditions. Since 2009, a total of 25 C. gattii infections, 23 (92%) caused by non-outbreak strain C. gattii, have been reported from 8 non-Pacific Northwest states. Sixteen (64%) patients were previously healthy, and 21 (84%) were male; median age was 43 years (range 15-83 years). Ten patients who provided information reported no past-year travel to areas where C. gattii is known to be endemic. Nineteen (76%) patients had central nervous system infections; 6 (24%) died. C. gattii infection in persons without exposure to known disease-endemic areas suggests possible endemicity in the United States outside the outbreak-affected region; these infections appear to differ in clinical and demographic characteristics from outbreak-associated C. gattii. Clinicians outside the outbreak-affected areas should be aware of locally acquired C. gattii infection and its varied signs and symptoms.

Características histomorfológicas e histoquímicas determinantes no diagnóstico da criptococose em animais de companhia

Sete casos de criptococose (seis gatos e um cão) foram estudados para estabelecer as características histomorfológicas e histoquímicas determinantes no diagnóstico histopatológico dessa condição. Os dados complementares relacionados à epidemiologia, aos aspectos clínicos, à localização das lesões e às alterações macroscópicas foram obtidos dos protocolos de necropsias e biópsias. Na histologia, as leveduras foram observadas no interior de macrófagos ou livres no parênquima, associadas à reação inflamatória linfo-histioplasmocítica que variou de escassa a acentuada. Pela técnica de hematoxilina-eosina (HE) as leveduras eram arredondadas, com célula central contendo um núcleo, circundada por um halo claro (cápsula geralmente não corada). As técnicas histoquímicas do ácido periódico de Schiff (PAS), Grocott e Fontana-Masson (FM) foram utilizadas e evidenciaram a parede das células das leveduras. Pelo FM observou-se a melanina presente nessas células. As técnicas do azul Alciano e da mucicarmina de Mayer evidenciaram principalmente a cápsula polissacarídica das leveduras. O diâmetro das células das leveduras variou de 1,67 a 10,00µm e o diâmetro total das leveduras encapsuladas variou entre 4,17 e 34,16µm. Os brotamentos foram melhor visualizados através do PAS e ocorreram em base estreita, de forma única ou múltipla, principalmente em polos opostos das células das leveduras ou formando uma cadeia. O diagnóstico definitivo de criptococose foi estabelecido através do exame histopatológico, baseando-se na morfologia característica do agente (levedura encapsulada) e em suas propriedades tintoriais (histoquímicas), principalmente nos casos em que a cultura micológica não foi realizada.

Occurrence and molecular characterization of cryptococcosis in dogs and cats in Mato Grosso, Brazil

Cryptococcosis is an infection that affects humans and animals, the etiology is attributed to Cryptococcus neoformans variety neoformans, C. neoformans var. grubii and Cryptococcus gattii. The infection is common in dogs and cats, causing respiratory, neurological, cutaneous and ocular infections. Aiming to better understand the epidemiology of cryptococcosis in animals in the region, this paper describe the occurrence and characterization of the Cryptococcus species involved in this illness in pet animals at Mato Grosso State, Brazil. Clinical samples of four cases, two in cats and two dogs, were submitted for pathological, microbiological and molecular analysis. Microscopically, in three cases, tissue sections stained with hematoxylin and eosin had absence to severe granulomatous reaction composed by histiocytes, multinucleated cells and lymphocytes infiltration. In one case, citological imprint analysis showed similar inflammatory mainly mononuclear and lymphocyte cells infiltration. All cases had variable amounts of intracellular and extracellular fungal structures compatible with Cryptococcus sp. on Periodic Acid-Schiff (PAS) stain. All clinical samples were positive for culture on Sabouraud Dextrose Agar (SDA) and morphologically classified as Cryptococcus sp. The isolates were PCR positive for C. gatti, being confirmed by sequencing technique. The findings characterize the molecular species involved in animal infections in the region, and may contribute to future studies of the epidemiology of C. gattii.