Publications

TitleAbstractYear(sorted ascending)
Filter
PMID
Filter
evidence of recombination in mixed-mating-type and alpha-only populations of cryptococcus gattii sourced from single eucalyptus tree hollows.disease caused by the pathogenic yeast cryptococcus gattii begins with the inhalation of an infectious propagule. as c. gattii is heavily encapsulated, this propagule is most likely to be a basidiospore. however, most c. gattii strains are infertile in laboratory crosses, and population studies indicate that recombination and dispersal are very restricted. in addition, strains of the alpha mating type predominate, which would not be expected in a mating population. c. gattii comprises four genet ...200818281600
communicating the risks of a new, emerging pathogen: the case of cryptococcus gattii.the news media are an important channel for communicating public health messages, providing important information about geographic extent, symptoms, and precautionary measures. this function may be particularly important in the case of new and emerging infectious diseases, which are unfamiliar to both the public and health professionals. we conducted a content analysis of the coverage in six canadian newspapers of two emerging infectious pathogens in british columbia (bc), west nile virus and cr ...200818419655
cryptococcus neoformans isolated from passerine and psittacine bird excreta in the state of paraná, brazil.cryptococcus neoformans is an opportunistic basidiomycete yeast that causes life-threatening infections as meningoencephalitis primarily in immunocompromised hosts, generally associated with aids. the source of this organism is mainly pigeon excreta; however, other avian species' excreta are implicated as a source of this yeast. the occurrence of c. neoformans and cryptococcus gattii in bird excreta in the state of paraná in brazil was determined in this study. a total of 141 samples of passerin ...200818459065
[cryptococcosis and pets].this paper is a review of cryptococcosis in domestic animals. cryptococcosis is an uncommon mycosis in domestic animals and its occurrence is sporadic. the disease is caused by cryptococcus neoformans, although cryptococcus gattii has been also isolated from different animal species. although cryptococcosis has been reported in several animal species, the most frequently affected domestic animal is the cat. the present paper deals with feline and canine cryptococcosis, its common clinical signs ...200818338916
diversity of the cryptococcus neoformans-cryptococcus gattii species complex.more than 110 years of study of the cryptococcus neoformans and cryptococcus gattii species complex has resulted in an enormous accumulation of fundamental and applied biological and clinical knowledge. recent developments in our understanding of the diversity within the species complex are presented, emphasizing the intraspecific complexity, which includes species, microspecies, hybrids, serotypes and genotypes. each of these may have different roles in disease. an overview of obsolete and curr ...200818338917
[urease activity in cryptococcus neoformans and cryptococcus gattii].urease is an enzyme considered one of the main virulence factors in cryptococcus neoformans. quantitative differences in urease production between c. neoformans and the new species cryptococcus gattii have not been so far documented. using a standardized method, 25 isolates of c. neoformans and 19 of c. gattii were seeded in christensen urea broth medium for urease activity detection. approximately, the 50% of activity of one unit of commercial jack beans urease (a550=0.215) was considered as a ...200818338924
isolates of cryptococcus neoformans from infected animals reveal genetic exchange in unisexual, alpha mating type populations.sexual reproduction and genetic exchange are important for the evolution of fungal pathogens and for producing potentially infective spores. studies to determine whether sex occurs in the pathogenic yeast cryptococcus neoformans var. grubii have produced enigmatic results, however: basidiospores are the most likely infective propagules, and clinical isolates are fertile and genetically diverse, consistent with a sexual species, but almost all populations examined consist of a single mating type ...200818552280
in vitro susceptibility of cryptococcus gattii clinical isolates.the data available in the literature concerning cryptococcus gattii in vitro antifungal susceptibility are contradictory. we have analyzed the activity of eight antifungal agents against 23 c. gattii clinical isolates and compared the susceptibility profiles with those of c. neoformans. mic analysis (mg/l) revealed that c. gattii isolates were more susceptible to amphotericin b and flucytosine than were c. neoformans isolates. fluconazole and other azole compounds showed high mic values for c. g ...200818558948
evaluation of etest method for determining isavuconazole mics against cryptococcus gattii and cryptococcus neoformans.we compared etest with broth microdilution testing for isavuconazole activity against 92 cryptococcus isolates. a 97.8% agreement was found between these methods, without major discrepancies (>2-well dilution difference). our findings support the use of the etest methodology as a reliable method for the determination of mics against cryptococcus spp.200818559645
phenotypic switching of cryptococcus neoformans and cryptococcus gattii.microorganisms that live in fluctuating environments must constantly adapt their behavior to survive. the host constitutes an important microenvironment in opportunistic and primary fungal pathogens like cryptococcus neoformans (c. neoformans) and cryptococcus gattii (c. gattii). in clonal populations, adaptation may be achieved through the generation of diversity. for fungi phenotype switching constitutes a mechanism that allows them to change rapidly. both c. neoformans and c. gattii undergo p ...200818568418
the expanding host tree species spectrum of cryptococcus gattii and cryptococcus neoformans and their isolations from surrounding soil in india.this study reports the widespread prevalence of cryptococcus neoformans and cryptococcus gattii in decayed wood inside trunk hollows of 14 species representing 12 families of trees and from soil near the base of various host trees from delhi and several places in the indian states of uttar pradesh, haryana, tamil nadu and chandigarh union territory. of the 311 trees from which samples were obtained, 64 (20.5%) were found to contain strains of the c. neoformans species complex. the number of tree ...200818608895
multilocus microsatellite typing for cryptococcus neoformans var. grubii.fifteen randomly selected microsatellites (simple sequence repeats; ssrs), from the h99 cryptococcus neoformans var. grubii (serotype a) genome, were sequenced, characterized and applied to sequence 87 clinical and environmental c. neoformans var. grubii isolates from 12 different countries based on multilocus microsatellite typing (mlmt). among the 15 ssr loci, three (designated cng1, cng2 and cng3) were polymorphic, while the remaining 12 ssr loci showed no variations. the specific pcr primers ...200818608927
[in vitro determination of virulence factors activity associated with several cryptococcus neoformans clinical isolates].different phenotypic characteristics associated with virulence of the cryptococcus neoformans species complex have shown an important role in their pathogenicity. in this study we have determined the role of phenotypically and genotypically factors of some virulence factors from clinical isolates in the two species of the complex; 35 c. neoformans and 19 cryptococcus gattii. growth at 37 degrees c, macroscopic and microscopic morphology, switching phenomenon, activity of 23 extracellular enzymes ...200818785782
laccase activity in cryptococcus gattii strains isolated from goats.cryptococcosis is a life-threatening infection in humans and animals caused by encapsulated yeasts of the genus cryptococcus. cryptococcus neoformans and cryptococcus gattii are the main agents of this mycosis. until 2002 c. gattii was classified as a variety of c. neoformans but now is accepted as an independent species. the laccase (phenoloxydase) enzyme produced by these yeasts is considered one of the main pathogenic factors for its ability to induce melanin from dihydroxyphenolic compounds. ...200818785783
[first isolation of cryptococcus gattii from the environment in the state of espírito santo].the presence of cryptococcus gattii was investigated in different regions of the state of espírito santo. the largest number (73) of samples was collected from trees located in public places in vitória; 47 came from preserved areas or areas with only minor human impact, surrounding this city, at altitudes from 0 to 900m above sea level; 48 came from trees native of the northern and southern regions of the state. the samples were collected from tree hollows and trunks by of swabs and yielded two ...200819009184
simultaneous identification of molecular and mating types within the cryptococcus species complex by pcr-rflp analysis.the cryptococcus species complex consists of two species, cryptococcus neoformans and cryptococcus gattii, which cause systemic infections in both immunocompromised and immunocompetent patients. both species have a bipolar mating system, with mating type (mat) alpha being predominant in clinical and environmental isolates. the strains of the cryptococcus species complex have been divided into eight major molecular types, which show differences in epidemiology, biology and pathogenicity. in this ...200819018017
regional pattern of the molecular types of cryptococcus neoformans and cryptococcus gattii in brazil.the molecular types of 443 brazilian isolates of cryptococcus neoformans and cryptococcus gattii were analyzed to determine their geographic distribution within brazil and their underlying host conditions. the following data, imported from previous epidemiological studies as well as two culture collections, were analyzed for: place of isolation, source (clinical or environmental), host risk factors, species, serotype, mating type, and molecular type. molecular typing by pcr-fingerprinting using ...200818797758
cryptococcus gattii infections on vancouver island, british columbia, canada: emergence of a tropical fungus in a temperate environment.cryptococcus gattii causes disease among immunocompetent individuals in the tropics and subtropics. we document the appearance of c. gattii infections on vancouver island (vi), a temperate region, and discuss reasons for this emergence.200818802986
genotype and mating type analysis of cryptococcus neoformans and cryptococcus gattii isolates from china that mainly originated from non-hiv-infected patients.cryptococcosis has been reported to be mostly associated with non-hiv-related patients in china. however, little is known about the molecular characteristics of clinical isolates from the cryptococcus neoformans species complex in this country. in this study, 115 clinical isolates were included. molecular type vni was the most representative (n=103), followed by vgi (n=8), vniii (n=2), vniv (n=1), and vgii (n=1). with the exception of a serotype d mating type a isolate, all possessed the matalph ...200818671745
cryptococcus gattii: an emerging cause of pulmonary nodules.since the fall of 1999, a new endemic focus of cryptococcus gattii serotype b infection has emerged on vancouver island (victoria, british columbia), with infections occurring in both animals and humans. in the human cases, symptoms have manifested as pulmonary nodules, meningitis or both. this organism has added a new nonmalignant cause of pulmonary nodules to the literature, resulting in a change in the management of these nodules by health care professionals.200818437258
cryptococcus neoformans strains and infection in apparently immunocompetent patients, china.to determine the population structure of the cryptococcosis agents in china, we analyzed the genotype of 120 cryptococcus neoformans and 9 cryptococcus gattii strains isolated from 1980 through 2006 from cryptococcosis patients residing in 16 provinces of mainland china. a total of 71% (91/129) of the clinical strains isolated from 1985 through 2006 were from patients without any apparent risk factors. only 8.5% (11/129) were from aids patients; the remaining 20.5% (27/129) were from patients wi ...200818439357
association between fertility and molecular sub-type of global isolates of cryptococcus gattii molecular type vgii.the basidiomycetous yeast cryptococcus gattii, is a primary pathogen which causes disease in apparently healthy humans and a wide range of animals. recently, an outbreak of cryptococcosis caused by a previously uncommon genotype of c. gattii, vgii, emerged on vancouver island, british columbia, canada. two pathogenic sub-types of vgii (designated vgiia and vgiib) were identified among these isolates. all of the isolates proved to be mating type alpha and had exceptionally high sporulation capaci ...200818651305
[cryptococcus gattii meningitis: observation in a spanish patient]. 200818588823
natural occurrence and growth reaction on canavanine-glycine-bromothymol blue agar of non-neoformans cryptococcus spp. in malaysia.cryptococcus albidus and c. laurentii were the predominant non-neoformans cryptococci isolated during an environmental sampling study for c. gattii at klang valley, malaysia. cryptococcus gattii was not isolated from any of the environmental samples. cryptococcus albidus and c. laurentii were isolated mainly from vegetative samples of eucalyptus trees and bird droppings. upon testing on canavanine-glycine-bromothymol blue (cgb) agar, all the c. albidus isolates remained unchanged. interestingly, ...200818498307
torsades de pointes in a patient receiving fluconazole for cerebral cryptococcosis.a case of torsades de pointes associated with fluconazole use is described.200818359968
pulmonary cryptococcosis.cryptococcosis is a common opportunistic infection in acquired immunodeficiency syndrome (aids) patients, also occurring in other immunosuppressed patients and occasionally those with no apparent immunocompromise. the majority of cases are caused by the ubiquitous encapsulated yeast, cryptococcus neoformans, whereas cryptococcus gattii accounts for a smaller proportion of cases, often in immunocompetent patients. severe meningoencephalitis is the commonest presentation; however, pulmonary crypto ...200818365996
mics and minimum fungicidal concentrations of posaconazole, voriconazole and fluconazole for cryptococcus neoformans and cryptococcus gattii. 200818375969
the emergence of cryptococcus gattii in british columbia and the pacific northwest.an unprecedented emergence of cryptococcal infections in animals and otherwise healthy humans was recognized in 1999 on the east coast of vancouver island, british columbia. unexpectedly, these infections were caused by cryptococcus gattii, a species closely related to the aids-associated fungal pathogen cryptococcus neoformans. human cases have continued over the past 8 years and now total approximately 170 with eight deaths. extensive environmental sampling, coupled with detailed molecular typ ...200818377817
antibody action after phagocytosis promotes cryptococcus neoformans and cryptococcus gattii macrophage exocytosis with biofilm-like microcolony formation.antibody-mediated phagocytosis was discovered over a century ago but little is known about antibody effects in phagolysosomes. we explored the consequences of antibody-mediated phagocytosis for two closely related human pathogenic fungal species, cryptococcus neoformans and cryptococcus gattii, of which c. neoformans encompasses two varieties: neoformans and grubii. the interaction between c. neoformans varieties grubii and neoformans and host cells has been extensively studied, but that of c. g ...200818384661
cryptococcus species identification by multiplex pcr.members of the cryptococcus species complex are encapsulated basidiomycetous yeasts, which can affect the central nervous system (cns) and if untreated may cause meningitis. cryptococcus neoformans is an opportunistic pathogen causing infections mainly in immunocompromised individuals. cryptococcus gattii is a primary pathogen responsible for a high incidence of cryptococcomas in the lung and brain and shows a delayed response to antifungal therapy. the differentiation between the two species is ...200818415847
six monophyletic lineages identified within cryptococcus neoformans and cryptococcus gattii by multi-locus sequence typing.cryptococcus neoformans and cryptococcus gattii are closely related pathogenic basidiomycetous yeasts in which six haploid genotypic groups have been distinguished. the two haploid genotypic groups of c. neoformans have been described as variety grubii and variety neoformans. the four c. gattii genotypic groups have, however, not been described as separate taxa. one hundred and seventeen isolates representing all six haploid genotypic groups were selected for multi-locus sequence typing using si ...200818261945
epidemiology and management of cryptococcal meningitis: developments and challenges.the significance of cryptococcal infection as a cause of human disease has dramatically evolved in recent years. the objective of this study was to outline the worldwide significance of cryptococcosis and review developments in the management of cryptococcal meningitis. cryptococcus neoformans var. grubii remains an important cause of disease, particularly in hosts with acquired immunosuppression. cryptococcus gattii, on the other hand, infects hosts with seemingly normal immune systems and a re ...200818312157
isolation of cryptococcus neoformans and cryptococcus gattii from trunk hollows of living trees in buenos aires city, argentina.the aim of this work was to describe the distribution of the members of the cryptococcus species complex (cryptococcus neoformans and c. gattii) in hollows of trees from seven parks in buenos aires city, to determine the serotypes and genotypes of these environmental isolates and to compare them with the ones reported in the 2001 survey. four hundred and eighty nine samples were collected by swabbing all trees which had hollows or fissures in the seven parks studied. each tree was sampled once d ...200918654914
identification of genomic differences between cryptococcus neoformans and cryptococcus gattii by representational difference analysis (rda).cryptococcus neoformans and cryptococcus gattii are basidiomycetous yeasts that cause cryptococcosis in immunocompromised and immunocompetent individuals, respectively. in this study, representational difference analysis (rda) was applied to isolate sequences representing genomic differences between c. neoformans var. grubii and c. gattii. rda is a pcr based subtractive enrichment procedure for isolating the differences between two nearly identical genomes. we have approximately 200 clones seque ...200918668420
histopathology, serology and cultures in the diagnosis of cryptococcosis.cryptococcosis is one of the most common opportunistic fungal infections in patients with acquired immunodeficiency syndrome (aids). we report 13 cases of cryptococcal infection based on histopathology, serology and cultures. epidemiological analysis, histochemical techniques of hematoxilin and eosin (he) and grocot's silver (gms), as well special histochemical techniques such as mayer's mucicarmine (mm) and fontana-masson (fm), cryptococcal antigen test (crag) and isolation on fungal media: sab ...200919893977
real-time polymerase chain reaction detection of cryptococcus neoformans and cryptococcus gattii in human samples.we report a taqman real-time polymerase chain reaction (pcr) protocol for diagnosing cryptococcosis. specificity was tested with 33 fungal strains. the 7 clinical samples found positive by culture also tested positive by real-time pcr. no false negatives were found among the 94 clinical samples that were negative by culture for cryptococcus spp. the sensitivity threshold was about 10 plasmid copies per assay.200919679239
cryptococcus gattii: an emerging cause of fungal disease in north america.during the latter half of the twentieth century, fungal pathogens such as cryptococcus neoformans were increasingly recognized as a significant threat to the health of immune compromised populations throughout the world. until recently, the closely related species c. gattii was considered to be a low-level endemic pathogen that was confined to tropical regions such as australia. since 1999, c. gattii has emerged in the pacific northwest region of north america and has been responsible for a larg ...200919503836
divergence, hybridization, and recombination in the mitochondrial genome of the human pathogenic yeast cryptococcus gattii.the inheritance of mitochondrial genes and genomes are uniparental in most sexual eukaryotes. this pattern of inheritance makes mitochondrial genomes in natural populations effectively clonal. here, we examined the mitochondrial population genetics of the emerging human pathogenic fungus cryptococcus gattii. the dna sequences for five mitochondrial dna fragments were obtained from each of 50 isolates belonging to two evolutionary divergent lineages, vgi and vgii. our analyses revealed a greater ...200919457185
inteins in pathogenic fungi: a phylogenetic tool and perspectives for therapeutic applications.inteins or 'internal proteins' are coding sequences that are transcribed and translated with flanking sequences (exteins). after translation, the inteins are excised by an autocatalytic process and the host protein assumes its normal conformation and develops its expected function. these parasitic genetic elements have been found in important, conserved proteins in all three domains of life. most of the eukaryotic inteins are present in the fungi kingdom and the prp8 intein is one of the most wi ...200919547879
dexamethasone in cryptococcus gattii central nervous system infection.clinical outcomes were reviewed for 4 patients with cryptococcus gattii central nervous system infection who received dexamethasone for the treatment of persisting mental status abnormalities and focal lesions on brain scan despite culture-negative cerebrospinal fluid and the management of intracranial pressure. favorable clinical responses were observed in 3 patients. although corticosteroids are not recommended for the treatment of cryptococcal meningitis, these observations suggest that dexam ...200919589083
virulence in cryptococcus species.cryptococcus neoformans and cryptococcus gattii are the cause of life-threatening meningoencephalitis in immunocompromised and immunocompetent individuals respectively. the increasing incidence of cryptococcal infection as a result of the aids epidemic, the recent emergence of a hypervirulent cryptococcal strain in canada and the fact that mortality from cryptococcal disease remains high have stimulated intensive research into this organism. here we outline recent advances in our understanding o ...200919245939
nasal cryptococcosis in two dogs in new zealand.two young, large-breed female dogs were presented with an acute onset of sneezing and nasal discharge. one patient had concurrent epistaxis and facial deformity.200919252544
promiscuous mitochondria in cryptococcus gattii.cryptococcus gattii is a primary pathogenic basidiomycetous yeast comprising four genotypic groups. here we present data on two mitochondrial loci (mtlrrna and atp6). two of the genotypic groups, namely amplified fragment length polymorphism (aflp)5/vgiii and aflp6/vgii, formed monophyletic lineages. the aflp4/vgi genotypic group, however, possessed five different mitochondrial genotypes that did not form a monophyletic lineage. the majority of these isolates contained mitochondrial genomes that ...200919281475
new its genotype of cryptococcus gattii isolated from an aids patient in brazil.based on combinations of nine variable nucleotides at nine different base positions in the its1-5.8s-its2 region, cryptococcus gattii strains were classified into six genotypes. a new genotype of c. gattii, designated as its type 8, was isolated from an aids patient in brazil. the its type 8 strain is closely related to the its type 4 strain, which has been frequently isolated in brazil and the usa, but which shows its-signatured nucleotide difference at each nucleotide position. the its type 8 ...200919291095
cryptococcosis in domestic animals in western australia: a retrospective study from 1995-2006.a retrospective study of cryptococcosis in domestic animals residing in western australia was conducted over an 11-year-period (from 1995 to 2006) by searching the data base of murdoch university veterinary teaching hospital and the largest private clinical pathology laboratory in perth. cryptococcosis was identified in 155 animals: 72 cats, 57 dogs, 20 horses, three alpacas, two ferrets and a sheep. there was no seasonal trend apparent from the dates of diagnosis. taking into account the common ...200919306217
role of complement in protection against cryptococcus gattii infection.previous studies have shown that the alternative pathway of complement activation plays an important role in protection against infection with cryptococcus neoformans. cryptococcus gattii does not activate the alternative pathway as well as c. neoformans in vitro. the role of complement in c. gattii infection in vivo has not been reported. in this study, we used mice deficient in complement components to investigate the role of complement in protection against a c. gattii isolate from an ongoing ...200919114546
phylogeny and phenotypic characterization of pathogenic cryptococcus species and closely related saprobic taxa in the tremellales.the basidiomycetous yeasts cryptococcus neoformans and cryptococcus gattii are closely related sibling species that cause respiratory and neurological disease in humans and animals. within these two recognized species, phylogenetic analysis reveals at least six cryptic species defined as molecular types (vni/ii/b, vniv, vgi, vgii, vgiii, and vgiv) that comprise the pathogenic cryptococcus species complex. these pathogenic species are clustered in the filobasidiella clade within the order tremell ...200919151324
molecular evidence that the range of the vancouver island outbreak of cryptococcus gattii infection has expanded into the pacific northwest in the united states.cryptococcus neoformans frequently causes fungal meningitis in immunocompromised patients, whereas the related species c. gattii is restricted to tropical and subtropical regions,where it usually infects immunocompetent individuals.an outbreak of c. gattii infection that began in 1999 on vancouver island has resulted in endemic c. gattii infection and caused numerous human and veterinary infections; the outbreak's range has spread to mainland british columbia. the outbreak-related isolates have ...200919220140
cryptococcal meningitis with an antecedent cutaneous cryptococcal lesion.cutaneous cryptococcosis, caused by an encapsulated yeast, cryptococcus neoformans, is generally associated with concomitant systemic infection. here we report a case of primary cutaneous cryptococcosis with spread to central nervous system in an hiv seronegative young boy. in the present case, a 17-year-old boy who was suffering from a non-healing ulcer on his right great toe for 5 months, presented with the signs and symptoms of meningitis. cryptococcus neoformans var. gattii was isolated from ...200919930999
genotyping of mexican cryptococcus neoformans and c. gattii isolates by pcr-fingerprinting.cryptococcosis in méxico is caused by both species of the cryptococcus species complex i.e., cryptococcus neoformans and c. gattii. the current study was aimed to determine genetic variability of 72 mexican clinical isolates using pcr-fingerprinting with the primer m13. pcr fingerprinting revealed 55 vni, five vnii, three vniii, one vniv, two vgi, two vgii, two vgiii and two vgiv isolates among those studied. the results show that most cryptococcosis cases in méxico are aids related and are caus ...200919888804
cryptococcus gattii outbreak expands into the northwestern united states with fatal consequences.in the past decade, the primary fungal pathogen cryptococcus gattii has evolved and adapted to the temperate climate of the pacific northwest region of north america. this pathogen is now endemic and an increasingly common cause of life-threatening pulmonary and central nervous system infections that are difficult to manage and, in some cases, fatal to humans and other mammals throughout the region. a series of recent reports provide evidence that evolutionary, climatic, and anthropogenic factor ...200920150950
spores as infectious propagules of cryptococcus neoformans.cryptococcus neoformans and cryptococcus gattii are closely related pathogenic fungi that cause pneumonia and meningitis in both immunocompromised and immunocompetent hosts and are a significant global infectious disease risk. both species are found in the environment and are acquired via inhalation, leading to an initial pulmonary infection. the infectious propagule is unknown but is hypothesized to be small desiccated yeast cells or spores produced by sexual reproduction (opposite- or same-sex ...200919620339
cryptococcus gattii isolates from the british columbia cryptococcosis outbreak induce less protective inflammation in a murine model of infection than cryptococcus neoformans.the fungal pathogen cryptococcus neoformans causes approximately one million cases of cryptococcosis per year in people with aids. in contrast, the related species c. gattii is responsible for a much smaller number of cases, but these often occur in immunocompetent people. in fact, c. gattii has emerged in the last decade as the frequent cause of cryptococcosis in otherwise healthy people in british columbia. we analyzed the immune responses elicited by three c. gattii strains and one c. neoform ...200919635827
the fatal fungal outbreak on vancouver island is characterized by enhanced intracellular parasitism driven by mitochondrial regulation.in 1999, the population of vancouver island, canada, began to experience an outbreak of a fatal fungal disease caused by a highly virulent lineage of cryptococcus gattii. this organism has recently spread to the canadian mainland and pacific northwest, but the molecular cause of the outbreak remains unknown. here we show that the vancouver island outbreak (vio) isolates have dramatically increased their ability to replicate within macrophages of the mammalian immune system in comparison with oth ...200919651610
the trehalose synthesis pathway is an integral part of the virulence composite for cryptococcus gattii.the trehalose pathway is essential for stress tolerance and virulence in fungi. we investigated the importance of this pathway for virulence of the pathogenic yeast cryptococcus gattii using the highly virulent vancouver island, canada, outbreak strain r265. three genes putatively involved in trehalose biosynthesis, tps1 (trehalose-6-phosphate [t6p] synthase) and tps2 (t6p phosphatase), and degradation, nth1 (neutral trehalose), were deleted in this strain, creating the r265tps1 delta, r265tps2 ...200919651856
spread of cryptococcus gattii into pacific northwest region of the united states.cryptococcus gattii has emerged as a human and animal pathogen in the pacific northwest. first recognized on vancouver island, british columbia, canada, it now involves mainland british columbia, and washington and oregon in the united states. in canada, the incidence of disease has been one of the highest worldwide. in the united states, lack of cryptococcal species identification and case surveillance limit our knowledge of c. gattii epidemiology. infections in the pacific northwest are caused ...200919757550
identification of cryptococcus gattii by use of l-canavanine glycine bromothymol blue medium and dna sequencing.cryptococcus neoformans and cryptococcus gattii are closely related pathogenic fungi. cryptococcus neoformans is ecologically widespread and affects primarily immunocompromised patients, while c. gattii is traditionally found in tropical climates and has been reported to cause disease in immunocompetent patients. l-canavanine glycine bromothymol blue (cgb) agar can be used to differentiate c. neoformans and c. gattii, but there are few reports of its performance in routine clinical practice. gro ...200919794048
isolation and purification of antigenic components of cryptococcus.the encapsulated fungal pathogens cryptococcus neoformans and cryptococcus gattii are significant agents of life-threatening infections, particularly in persons with suppressed cell-mediated immunity. this chapter provides detailed methodology for the purification of two of the major antigen fractions of c. neoformans: glucuronoxylomannan (gxm) and mannoprotein (mp). gxm is the primary component of the polysaccharide capsule, which is the major cryptococcal virulence factor. in contrast, mps hav ...200919089377
clinical presentation, diagnosis and management of cryptococcus gattii cases: lessons learned from british columbia.the environmental fungus cryptococcus gattii emerged on vancouver island, british columbia (bc), in 1999. by the end of 2006, it led to 176 cases and eight deaths - one of the highest burdens of c gattii disease worldwide. the present paper describes three cases, and the bc experience in the diagnosis and management of this infection. all three cases presented with pulmonary findings, including cryptococcomas and infiltrates. one also presented with brain cryptococcomas. cases were diagnosed by ...200920190892
[first description of phenotypic profile and in vitro drug susceptibility of cryptococcus spp yeast isolated from hiv-positive and hiv-negative patients in state of mato grosso].thirty-seven isolates from 10 hiv-negative and 26 hiv-positive patients in mato grosso were evaluated. direct examination, culturing and chemotyping of species were performed. ketoconazole, itraconazole, voriconazole, fluconazole and amphotericin b were evaluated. thirty-seven yeasts of cryptococcus spp were identified, of which 26 were from hiv-positive patients (25 cryptococcus neoformans and one cryptococcus gattii) and 10 from hiv-negative patients (five cryptococcus neoformans and five cryp ...200920209351
[systemic mycosis: factors associated with death among patients infected with the human immunodeficiency virus, cuiabá, state of mato grosso, brazil, 2005-2008].between 2005 and 2008, the prevalence of systemic mycosis among 1,300 hiv/aids patients in cuiabá, mato grosso, was 4.6%. the fungus species isolated were cryptococcus neoformans in 50%, cryptococcus gattii in 1.6%, cryptococcus spp in 6.6%, histoplasma capsulatum in 38.3% and paracoccidioides brasiliensis in 3.3%. death was recorded in the cases of 32 patients (53.3%), and cryptococcosis was the main cause. the cd4+ t lymphocyte count was low and similar among patients who survived or died due ...200920209358
cryptococcus gattii with bimorphic colony types in a dog in western oregon: additional evidence for expansion of the vancouver island outbreak.cryptococcus gattii was isolated from a 1.5-year-old dog with systemic cryptococcosis in oregon. the dog had no link to vancouver island or british columbia, canada. samples from a nasal swab and from a granulomatous mass within the cranial cavity were pooled for culture. colonies on sabouraud dextrose agar were mucoid and exhibited bimorphic morphology, melanin-pigmented and unpigmented. pigmented colonies were encapsulated budding spherical yeast, whereas unpigmented colonies were of unencapsu ...200919139515
first isolation of cryptococcus gattii molecular type vgii and cryptococcus neoformans molecular type vni from environmental sources in the city of belém, pará, brazil.cryptococcus neoformans and cryptococcus gattii are important agents of meningoencephalitis in humans in the city of belém. this clinical data suggests that the region may be a highly endemic area for the pathogenic cryptococcus species within the state of pará (pa), northern brazil. preliminary analysis of 11 environmental samples from the city of belém showed two positive locations, including a hollow of a kassod tree (senna siamea) colonized simultaneously by c. gattii molecular type vgii and ...200919722095
antifungal susceptibilities among different serotypes of cryptococcus gattii and cryptococcus neoformans.we measured antifungal activity against 128 cryptococcal isolates (86 of c. neoformans and 42 of c. gattii) to determine if differences in serotype susceptibility exist. contrary to previous results, we found no serotype susceptibility differences. isavuconazole, posaconazole, and voriconazole demonstrated excellent potency against each isolate and serotype, including isolates with reduced fluconazole susceptibilities.200918955539
cryptococcus gattii meningoencephalitis in an immunocompetent person 13 months after exposure.a 53-year old immunocompetent swiss female is described who developed severe meningoencephalitis due to infection with cryptococcus gattii 13 months following exposure on vancouver island, canada. diagnosis was based on cerebrospinal fluid (csf) examination, i.e., positive india-ink staining, positive latex particle agglutination, and positive culture. species identification was performed by growth on l-canavanine-glycine-bromthymol blue medium and by sequencing of the intergenic and internal tr ...200919390780
consensus multi-locus sequence typing scheme for cryptococcus neoformans and cryptococcus gattii.this communication describes the consensus multi-locus typing scheme established by the cryptococcal working group i (genotyping of cryptococcus neoformans and c. gattii) of the international society for human and animal mycology (isham) using seven unlinked genetic loci for global strain genotyping. these genetic loci include the housekeeping genes cap59,gpd1, lac1, plb1, sod1, ura5 and the igs1 region. allele and sequence type information are accessible at http://www.mlst.net/ .200919462334
cryptococcus gattii: emergence in western north america: exploitation of a novel ecological niche.the relatively uncommon fungal pathogen cryptococcus gattii recently emerged as a significant cause of cryptococcal disease in human and animals in the pacific northwest of north america. although genetic studies indicated its possible presence in the pacific northwest for more than 30 years, c. gattii as an etiological agent was largely unknown in this region prior to 1999. the recent emergence may have been encouraged by changing conditions of climate or land use and/or host susceptibility, an ...200919266091
cryptococcus neoformans serotype a and cryptococcus gattii serotype b isolates differ in their susceptibilities to fluconazole and voriconazole.this study presents antifungal susceptibility data for environmental isolates of cryptococcus neoformans serotype a (n=32) and cryptococcus gattii serotype b (n=18) to fluconazole and voriconazole employing disc diffusion and etest methods. the disc diffusion test was performed on mueller-hinton agar as recommended by the clinical and laboratory standards institute (clsi). for comparison, the disc diffusion test and etest were also performed on rpmi-1640 agar supplemented with 2% glucose. the pl ...200919195846
first reported case of cryptococcus gattii in the southeastern usa: implications for travel-associated acquisition of an emerging pathogen.in 2007, the first confirmed case of cryptococcus gattii was reported in the state of north carolina, usa. an otherwise healthy hiv negative male patient presented with a large upper thigh cryptococcoma in february, which was surgically removed and the patient was started on long-term high-dose fluconazole treatment. in may of 2007, the patient presented to the duke university hospital emergency room with seizures. magnetic resonance imaging revealed two large cns lesions found to be cryptococco ...200919516904
genetic diversity of the cryptococcus species complex suggests that cryptococcus gattii deserves to have varieties.the cryptococcus species complex contains two sibling taxa, cryptococcus neoformans and cryptococcus gattii. both species are basidiomycetous yeasts and major pathogens of humans and other mammals. genotyping methods have identified major haploid molecular types of c. neoformans (vni, vnii, vnb and vniv) and of c. gattii (vgi, vgii, vgiii and vgiv). to investigate the phylogenetic relationships among these haploid genotypes, we selected 73 strains from 2000 globally collected isolates investigat ...200919517012
investigation of plant extracts in traditional medicine of the brazilian cerrado against protozoans and yeasts.to investigate the activities of the 217 plant extracts in traditional medicine of the brazilian cerrado against protozoans and yeasts.201020600775
a prospective descriptive study of cryptococcal meningitis in hiv uninfected patients in vietnam - high prevalence of cryptococcus neoformans var grubii in the absence of underlying disease.most cases of cryptococcal meningitis occur in patients with hiv infection: the course and outcome of disease in the apparently immunocompetent is much more poorly understood. we describe a cohort of hiv uninfected vietnamese patients with cryptococcal meningitis in whom underlying disease is uncommon, and relate presenting features of patients and the characteristics of the infecting species to outcome.201020618932
antifungal therapy in a murine model of disseminated infection by cryptococcus gattii.we have evaluated the efficacy of posaconazole (psc), voriconazole (vrc), and amphotericin b (amb) in a murine model of systemic infection by cryptococcus gattii using immunocompromised animals and three clinical strains of the fungus. amb was the most effective drug in prolonging the survival of mice and also in reducing tissue burden in all organs tested. to a lesser degree, vrc at 60 mg/kg of body weight in lung tissue and psc at 40 mg/kg also in spleen demonstrated good efficacy in reducing ...201020625150
astemizole and an analogue promote fungicidal activity of fluconazole against cryptococcus neoformans var. grubii and cryptococcus gattii.cryptococcus neoformans is the leading cause of fungal meningitis, a life-threatening infection that occurs predominately in immuocompromised patients. current drug therapies are limited to amphotericin b, flucytosine and the azoles since the echinocandins have no demonstrated activity against yeast like pathogens. fluconazole, a drug belonging to the azole class and often the only available antifungal in the developing world, is fungistatic and therefore not effective in clearing cryptococcal i ...201019572230
emergence of cryptococcus gattii-- pacific northwest, 2004-2010.cryptococcus is a genus of fungi, of which two species, cryptococcus neoformans and cryptococcus gattii, cause nearly all human and animal cryptococcal infections. whereas c. neoformans primarily affects persons infected with human immunodeficiency virus (hiv) worldwide, c. gattii primarily affects hiv-uninfected persons in tropical and subtropical regions. in december 2004, a case of human c. gattii infection was reported in oregon, associated with an outbreak on vancouver island and in mainlan ...201020651641
molecular methods for the diagnosis and characterization of cryptococcus: a review.cryptococcosis is a fungal infection caused by yeasts of the genus cryptococcus, with cryptococcus neoformans and cryptococcus gattii as the primary pathogenic species. this disease is a threat to immunocompromised patients, especially those who have aids. however, the disease has also been described in healthy individuals. the tests used to identify these microorganisms have limitations that make final diagnosis difficult. however, currently there are specific gene sequences that can be used to ...201020657615
prevalence of the vnic genotype of cryptococcus neoformans in non-hiv-associated cryptococcosis in the republic of korea.pcr fingerprinting and multilocus sequence typing were applied to determine the major molecular types of the cryptococcus neoformans/cryptococcus gattii species complex in the republic of korea. of the 78 strains isolated from patients diagnosed with cryptococcosis between 1990 and 2008, 96% were c. neoformans serotype a, mating type matalpha and molecular type vni. the remaining 4% were c. gattii, serotype b, mating type matalpha and either molecular type vgiib or vgiii. of the 62 strains with ...201020561059
cryptococcus gattii genotype vgiia infection in man, japan, 2007.we report a patient in japan infected with cryptococcus gattii genotype vgiia who had no recent history of travel to disease-endemic areas. this strain was identical to the vancouver island outbreak strain r265. our results suggest that this virulent strain has spread to regions outside north america.201020587194
projecting global occurrence of cryptococcus gattii.cryptococcus gattii and c. neoformans cause pulmonary and systemic cryptococcosis. recently, c. gattii was recognized as a distinct pathogen of humans and animals. we analyzed information from 400 publications (1948-2008) to examine whether the fungus occurs globally. known distribution of c. gattii is possibly limited because specialized reagents for differentiation from c. neoformans are not readily available and not always used, and environmental surveys are patchy. however, autochthonous rep ...201020031037
clinical practice guidelines for the management of cryptococcal disease: 2010 update by the infectious diseases society of america.cryptococcosis is a global invasive mycosis associated with significant morbidity and mortality. these guidelines for its management have been built on the previous infectious diseases society of america guidelines from 2000 and include new sections. there is a discussion of the management of cryptococcal meningoencephalitis in 3 risk groups: (1) human immunodeficiency virus (hiv)-infected individuals, (2) organ transplant recipients, and (3) non-hiv-infected and nontransplant hosts. there are s ...201020047480
in-hospital mortality of hiv-infected cryptococcal meningitis patients with c. gattii and c. neoformans infection in gaborone, botswana.the clinical presentations and outcomes of cryptococcal meningitis (cm) may be associated with the cryptococcal species causing the infections. to evaluate clinical differences between cm caused by c. neoformans and cryptococcus gattii, we examined outcomes in hiv-infected adults with cm admitted to princess marina hospital in gaborone, botswana. among hiv-infected adults with cm, we found that 29 of 96 (30%) patients were infected with c. gattii, but species type was not associated with in-hosp ...201020438294
ecological niche modeling of cryptococcus gattii in british columbia, canada.cryptococcus gattii emerged on vancouver island, british columbia (bc), canada, in 1999, causing human and animal illness. environmental sampling for c.gattii in southwestern bc has isolated the fungal organism from native vegetation, soil, air, and water.201020439176
variability of phenotypic traits in cryptococcus varieties and species and the resulting implications for pathogenesis.variability of phenotypic characteristics in cryptococcus neoformans var. grubii and var. neoformans as well as cryptococcus gattii can have diverse effects on the virulence of these fungi and are thus important for pathogenesis. this article summarizes the diverse phenotypic changes that these fungi can manifest. we divide changes into those that affect the entire fungal population and are predominantly induced by environmental signals, and those that involve subpopulations of the fungal popula ...201020441549
cutaneous cryptococcosis due to cryptococcus gattii in a patient on chronic corticotherapy.cryptococcus gattii causes a form of endemic mycosis that most commonly affects the lungs and central nervous system of immunocompetent patients living in tropical and subtropical areas of the world. case report. a 66-year-old man who had chronic obstructive pulmonary disease without hiv infection and had been on systemic corticotherapy for several years developed extensive ulceration of the left forearm that was associated with ipsilateral supraclavicular adenomegaly, consequent to infection wi ...201020464157
isolation of cryptococcus gattii molecular type vgiii, from corymbia ficifolia detritus in colombia.an environmental sampling survey was carried out in different areas of bogotá, colombia, to obtain isolates of members of the cryptococcus neoformans/c. gattii species complex from corymbia ficifolia trees. during a 6-month period in 2007, 128 samples consisting of bark, soil around trunk bases, detritus, seeds and flowers were collected from 91 trees and processed according to standard procedures. the molecular type was determined using ura5 restriction fragment length polymorphism (rflp) analy ...201020465517
galactoxylomannans from cryptococcus neoformans varieties neoformans and grubii are structurally and antigenically variable.prior studies have established that the cryptococcus neoformans capsular polysaccharide component galactoxylomannan (galxm) manifests serotype-related structural differences that translate into antigenic differences. we analyzed galxm from acapsular serotype a and d strains by carbohydrate analysis and static and dynamic light scattering to determine mass, effective diameter, polydispersity, and diffusion coefficients. multiangle laser light scattering showed that galxm from c. neoformans var. g ...201020061411
the mating type locus (mat) and sexual reproduction of cryptococcus heveanensis: insights into the evolution of sex and sex-determining chromosomal regions in fungi.mating in basidiomycetous fungi is often controlled by two unlinked, multiallelic loci encoding homeodomain transcription factors or pheromones/pheromone receptors. in contrast to this tetrapolar organization, cryptococcus neoformans/cryptococcus gattii have a bipolar mating system, and a single biallelic locus governs sexual reproduction. the c. neoformans mat locus is unusually large (>100 kb), contains >20 genes, and enhances virulence. previous comparative genomic studies provided insights i ...201020502678
in vitro antifungal activities of bis(alkylpyridinium)alkane compounds against pathogenic yeasts and molds.ten bis(alkylpyridinium)alkane compounds were tested for antifungal activity against 19 species (26 isolates) of yeasts and molds. we then determined the mics and minimum fungicidal concentrations (mfcs) of four of the most active compounds (compounds 1, 4, 5, and 8) against 80 candida and 20 cryptococcal isolates, in comparison with the mics of amphotericin b, fluconazole, itraconazole, voriconazole, posaconazole, and caspofungin, using clinical laboratory and standards institutes broth microdu ...201020530227
epidemiology of cryptococcus gattii, british columbia, canada, 1999-2007.british columbia, canada, has the largest reported population of cryptococcus gattii-infected persons worldwide. to assess the impact of illness, we retrospectively analyzed demographic and clinical features of reported cases, hospitalizations, and deaths during 1999-2007. a total of 218 cases were reported (average annual incidence 5.8 per million persons). most persons who sought treatment had respiratory illness (76.6%) or lung cryptococcoma (75.4%). persons without hiv/aids hospitalized with ...201020113555
immunoproteomic approach to elucidating the pathogenesis of cryptococcosis caused by cryptococcus gattii.cryptococcosis caused by cryptococcus gattii is a devastating disease of immunocompetent hosts with an incompletely understood pathogenesis. utilizing an immunoproteomic approach in a naturally occurring koala model of disease, a number of key proteins and pathways are identified in the early and late pathogenesis of cryptococcosis for the first time. in particular, the thioredoxin system appears important in the pathogenesis of cryptococcosis caused by c. gattii vgii.201020545298
immunomodulatory effects of serotype b glucuronoxylomannan from cryptococcus gattii correlate with polysaccharide diameter.glucuronoxylomannan (gxm), the major capsular component in the cryptococcus complex, interacts with the immune system in multiple ways, which include the activation of toll-like receptors (tlrs) and the modulation of nitric oxide (no) production by phagocytes. in this study, we analyzed several structural parameters of gxm samples from cryptococcus neoformans (serotypes a and d) and cryptococcus gattii (serotypes b and c) and correlated them with the production of no by phagocytes and the activa ...201020547742
molecular typing and antifungal susceptibility of clinical and environmental cryptococcus neoformans species complex isolates in goiania, brazil.a total of 124 cryptococcus isolates, including 84 clinical strains obtained from cerebrospinal fluid from aids patients and 40 environmental isolates from pigeon excreta and from eucalyptus trees, were studied. the varieties, serotypes, phospholipase activity and molecular profile of these isolates were determined. cryptococcus neoformans var. grubii serotype a was identified in 120 isolates and cryptococcus gattii serotype b in four isolates. the clinical isolates showed higher phospholipase a ...201019500261
c-type lectin langerin is a beta-glucan receptor on human langerhans cells that recognizes opportunistic and pathogenic fungi.langerhans cells (lcs) lining the stratified epithelia and mucosal tissues are the first antigen presenting cells to encounter invading pathogens, such as viruses, bacteria and fungi. fungal infections form a health threat especially in immuno-compromised individuals. lcs express c-type lectin langerin that has specificity for mannose, fucose and glcnac structures. little is known about the role of human langerin in fungal infections. our data show that langerin interacts with both mannan and be ...201020097424
enzymatic characterisation of clinical isolates of cryptococcus neoformans, cryptococcus gattii and other environmental cryptococcus spp.this study compared the enzymatic activity of clinical isolates of cryptococcus neoformans, cryptococcus gattii, environmental isolates of c. neoformans and non-neoformans cryptococcus. most of the cryptococcal isolates investigated in this study exhibited proteinase and phospholipase activities. laccase activity was detected from all the c. neoformans and c. gattii isolates, but not from the non-neoformans cryptococcus isolates. there was no significant difference in the proteinase, phospholipa ...201019389064
a rare case of pulmonary cryptococcal inflammatory myofibroblastic tumor diagnosed by fine needle aspiration cytology.in a recent outbreak in british columbia (bc), canada, cryptococcus gattii, a rare species of cryptococcus, was noted to affect primarily immunocompetent hosts and cause limited pulmonary or cns disease. we herein report a rare case of a pulmonary inflammatory myofibroblastic tumor caused by a cryptococcus infection, presumed to be of the gattii species, in a 20-year-old immunocompetent college student from vancouver, bc who presented with a large lung mass. the diagnosis was first made on the f ...201019937947
correlation of genotype and in vitro susceptibilities of cryptococcus gattii strains from the pacific northwest of the united states.cryptococcus gattii emerged in north america in 1999 as a human and veterinary pathogen on vancouver island, british columbia. the emergent subtype, vgiia, and the closely related subtype vgiib can now be found in the united states in washington, oregon, and california. we performed multilocus sequence typing and antifungal susceptibility testing on 43 isolates of c. gattii from human patients in oregon, washington, california, and idaho. in contrast to vancouver island, vgiia was the most frequ ...201020007380
epidemiology of cryptococcosis in malaysia.this study describes the isolation of cryptococcus neoformans and cryptococcus gattii from patients with chronic meningitis who were admitted to 16 malaysian hospitals, from 2003 to 2004. of the 96 cryptococcal cases reported over the 2-year period, 74 (77.1%) patients were male and 45 (46.9%) patients were between 30 and 39 years old. cryptococcosis was uncommon in children. a total of 57 (59.4%) and 23 (24.0%) patients were malay and chinese respectively. human immunodeficiency virus infection ...201019627508
cryptococcus neoformans and cryptococcus gattii genes preferentially expressed during rat macrophage infection.cryptococcus neoformans and cryptococcus gattii are encapsulated yeast agents of cryptococcosis and facultative intracellular pathogens. the interaction of these yeasts with macrophages is essential for containing the infection. however, cryptococcus spp. overcome this initial host defense barrier using a unique pathogenic strategy involving intracellular replication and cytoplasmic accumulation of polysaccharide-containing vesicles. here, we employed representational difference analysis (rda) t ...201020302549
activated dormant cryptococcus gattii infection in a dutch tourist who visited vancouver island (canada): a molecular epidemiological approach.an ongoing outbreak of cryptococcus gattii-caused infections, which emerged on vancouver island and the pacific northwest, has affected more than 200 of the islands' residents, of whom eight died. while c. gattii infections are rarely described in travelers, we report a case of cryptococcosis caused by c. gattii in a patient treated with high dose corticosteroids for systemic lupus erythematosus induced autoimmune hemolytic anemia. she acquired the disease during a visit to vancouver island one ...201019824880
perilla frutescens seed agar, a new medium for identification of the cryptococcus species complex: evaluation for all major molecular types.here we present a new and simple medium made by perilla frutescens seed as a tool for identification of the cryptococcus species complex, namely cryptococcus neoformans and cryptococcus gattii. its usefulness was evaluated for all major molecular types within the cryptococcus species complex. as a result, this medium is better for identification of the species complex compared with guizotia abyssinica or helianthus annuus seed medium.201021182875
Refresh
firstprev
12345
nextlast
Displaying items 201 - 300 of 409