Genotypic characterization of environmental isolates of Cryptococcus gattii from Puerto Rico

Comparison of Cryptococcus gattii/neoformans Species Complex to Related Genera (Papiliotrema and Naganishia) Reveal Variances in Virulence Associated Factors and Antifungal Susceptibility

Cryptococcosis is an infectious disease of worldwide distribution, caused by encapsulated yeasts belonging to the phylum Basidiomycota. The genus Cryptococcus includes several species distributed around the world. The C. gattii/neoformans species complex is largely responsible for most cases of cryptococcosis. However, clinical series have been published of infections caused by Papiliotrema (Cryptococcus) laurentii and Naganishia albida (Cryptococcus albidus), among other related genera. Here, we examined the pathogenic potential and antifungal susceptibility of C. gattii/neoformans species complex (clades I and II) and related genera (Papiliotrema and Naganishia) isolated from environmental and clinical samples. P. laurentii (clade III), N. liquefasciens/N. albidosimilis (clade IV); and N. adeliensis/N. albida (clade V) strains produced higher levels of phospholipase and hemolysins, whereas the C. gattii/neoformans species complex strains (clades I and II) had markedly thicker capsules, produced more biofilm biomass and melanin, which are known virulence attributes. Interestingly, 40% of C. neoformans strains (clade II) had MICs above the ECV established for this species to amphotericin B. Several non-C. gattii/neoformans species complex (clades III to V) had MICs equal to or above the ECVs established for C. deuterogattii and C. neoformans for all the three antifungal drugs tested. Finally, all the non-C. gattii/neoformans clinical isolates (clades III to V) produced more melanin than the environmental isolates might reflect their particularly enhanced need for melanin during in vivo protection. It is very clear that C. gattii/neoformans species complex (clades I and II) strains, in general, show more similar virulence phenotypes between each other when compared to non-C. gattii/neoformans species complex (clades III to V) isolates. These observations together with the fact that P. laurentii and Naganishia spp. (clades III to V) strains were collected from the outside of a University Hospital, identify features of these yeasts important for environmental and patient colonization and furthermore, define mechanisms for infections with these uncommon pathogens.

Occurrence of Cryptococcus neoformans and other yeast-like fungi in environmental sources in Bonaire (Dutch Caribbean)

Introduction

We report here the presence of Cryptococcus neoformans, and other potentially pathogenic yeasts and yeast-like fungi in environmental sources in Bonaire.

Methods

Seventy environmental samples comprising 40 samples of old pigeon droppings, 18 of woody debris from hollows of living trees of Caesalpinia ('Divi Divi'), Ziziphus jujuba (Red Indian date), Tamarindus indica (Tamarind), Terminalia catappa (Tropical almond), Azadirachta indica (Neem) and 3 of other unidentified species of trees, 3 of latex from a rubber tree and 6 of coral dust were processed for isolation of pathogenic Cryptococcus spp. and other potentially pathogenic yeasts and yeast-like fungi. A variety of mycological media were employed. Identification of the isolates was done with conventional techniques and species identification was done by matrix-assisted laser desorption ionization-time of flight mass spectrometry.

Results

Three of the 40 samples from old pigeon droppings yielded Cryptococcus neoformans, constituting the first record of environmental occurrence of this important pathogenic yeast in the Dutch Caribbean. Other potentially pathogenic yeasts and yeast-like fungi recovered from these environmental samples included 6 isolates each of Candida albicans, 8 of Candida parapsilosis, 4 each of Candida metapsilosis and Candida orthopsilosis, 2 each of Candida carpophila, Candida famata, Candida fabianii and Candida pelliculosa, 7 of Candida spp., 5 of Trichosporon spp. and 2 of Sporobolomyces spp.

Conclusions

This study has demonstrated for the first time the occurrence of C. neoformans in a natural habitat in the Dutch Caribbean. The recovery of many species of potentially pathogenic yeast-like fungi and yeasts from environmental sources is remarkable.

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.

Report on novel environmental niches for Cryptococcus neoformans and Cryptococcus gattii in Colombia: Tabebuia guayacan and Roystonea regia

Knowledge of the environmental distribution of C. neoformans/C. gattii is important in the epidemiology and ecology of the etiological agent, which causes cryptococcosis, a deadly disease worldwide. The aim of this report is to describe the presence of C. neoformans/C. gattii in new environmental niches in Colombia. A total of 837 environmental samples were collected from six different species of trees across four cities; molecular type was determined by PCR fingerprinting and RFLP. Molecular type VNI and VGIII were isolated from different species of trees, resulting in two novel niches for this pathogen: Tabebuia guayacan and Roystonea regia.

Ecoepidemiology of Cryptococcus gattii in Developing Countries

Cryptococcosis is a systemic infection caused by species of the encapsulated yeast Cryptococcus. The disease may occur in immunocompromised and immunocompetent hosts and is acquired by the inhalation of infectious propagules present in the environment. Cryptococcus is distributed in a plethora of ecological niches, such as soil, pigeon droppings, and tree hollows, and each year new reservoirs are discovered, which helps researchers to better understand the epidemiology of the disease. In this review, we describe the ecoepidemiology of the C. gattii species complex focusing on clinical cases and ecological reservoirs in developing countries from different continents. We also discuss some important aspects related to the antifungal susceptibility of different species within the C. gattii species complex and bring new insights on the revised Cryptococcus taxonomy.

Cryptococcus tetragattii as a major cause of cryptococcal meningitis among HIV-infected individuals in Harare, Zimbabwe

OBJECTIVES

HIV-associated cryptococcal meningitis is commonly caused by Cryptococcus neoformans, whilst infections with Cryptococcus gattii sensu lato are historically rare. Despite available studies, little is known about the occurrence of C. gattii sensu lato infections among HIV-infected individuals in Zimbabwe.

METHODS

In a prospective cohort, we investigated the prevalence of C. gattii sensu lato meningitis among HIV-infected patients (n = 74) in Harare, Zimbabwe.

RESULTS

Of the 66/74 isolates confirmed by molecular characterization, 16.7% (11/66) were found to be C. gattii sensu lato and 83.3% (55/66) C. neoformans sensu stricto. From one patient two phenotypically different C. gattii sensu lato colonies were cultured. The majority (n = 9/12; 75%) of the C. gattii sensu lato isolates were Cryptococcus tetragattii (AFLP7/VGIV), which has been an infrequently reported pathogen. In-hospital mortality associated with C. gattii sensu lato was 36.4%.

CONCLUSIONS

Our data suggests that C. tetragattii (AFLP7/VGIV) is a more common cause of disease than C. gattii sensu stricto (genotype AFLP4/VGI) among patients with HIV-associated cryptococcal meningitis in Harare, Zimbabwe and possibly underreported in sub-Saharan Africa.

Environmental sampling of Ceratonia siliqua (carob) trees in Spain reveals the presence of the rare Cryptococcus gattii genotype AFLP7/VGIV

BACKGROUND

Cryptococcus gattii is a pathogenic basidiomycetous yeast that is emerging in temperate climate zones worldwide. C. gattii has repetitively been isolated from numerous tree species. Ongoing environmental sampling and molecular characterization is essential to understand the presence of this primary pathogenic microorganism in the Mediterranean environment.

AIMS

To report the first isolation of the rare C. gattii genotype AFLP7/VGIV from the environment in Europe.

METHODS

Samples were collected from woody debris of carob trees (Ceratonia siliqua) and olive trees (Olea europaea) in El Perelló, Tarragona, Spain. Cryptococcus species were further characterized by using URA5-RFLP, MALDI-TOF, AFLP and MLST. The antifungal susceptibility profile to amphotericin B, 5-fluorocytosine, fluconazole, itraconazole, posaconazole and voriconazole was determined using Sensititre Yeast One and E-test.

RESULTS

Cultures from one carob tree revealed the presence of ten Cryptococcus-like colonies. One colony was identified as C. gattii, and subsequent molecular characterization showed that it was an α mating-type that belonged to the rare genotype AFLP7/VGIV. Antifungal susceptibility testing showed values within the range of sensitivity described for other isolates of the same genotype and within the epidemiological cutoff values for this species.

CONCLUSIONS

The isolation of the rare C. gattii genotype AFLP7/VGIV in Spain is the first report in the European environment, implying the possible presence in other regions of the Mediterranean area, and underlines that clinicians must be aware for C. gattii infections in healthy individuals.

Recognition of seven species in the Cryptococcus gattii/Cryptococcus neoformans species complex

Phylogenetic analysis of 11 genetic loci and results from many genotyping studies revealed significant genetic diversity with the pathogenic Cryptococcus gattii/Cryptococcus neoformans species complex. Genealogical concordance, coalescence-based, and species tree approaches supported the presence of distinct and concordant lineages within the complex. Consequently, we propose to recognize the current C. neoformans var. grubii and C. neoformans var. neoformans as separate species, and five species within C. gattii. The type strain of C. neoformans CBS132 represents a serotype AD hybrid and is replaced. The newly delimited species differ in aspects of pathogenicity, prevalence for patient groups, as well as biochemical and physiological aspects, such as susceptibility to antifungals. MALDI-TOF mass spectrometry readily distinguishes the newly recognized species.

Cryptococcus gattii VGIII isolates causing infections in HIV/AIDS patients in Southern California: identification of the local environmental source as arboreal

Ongoing Cryptococcus gattii outbreaks in the Western United States and Canada illustrate the impact of environmental reservoirs and both clonal and recombining propagation in driving emergence and expansion of microbial pathogens. C. gattii comprises four distinct molecular types: VGI, VGII, VGIII, and VGIV, with no evidence of nuclear genetic exchange, indicating these represent distinct species. C. gattii VGII isolates are causing the Pacific Northwest outbreak, whereas VGIII isolates frequently infect HIV/AIDS patients in Southern California. VGI, VGII, and VGIII have been isolated from patients and animals in the Western US, suggesting these molecular types occur in the environment. However, only two environmental isolates of C. gattii have ever been reported from California: CBS7750 (VGII) and WM161 (VGIII). The incongruence of frequent clinical presence and uncommon environmental isolation suggests an unknown C. gattii reservoir in California. Here we report frequent isolation of C. gattii VGIII MATα and MATa isolates and infrequent isolation of VGI MATα from environmental sources in Southern California. VGIII isolates were obtained from soil debris associated with tree species not previously reported as hosts from sites near residences of infected patients. These isolates are fertile under laboratory conditions, produce abundant spores, and are part of both locally and more distantly recombining populations. MLST and whole genome sequence analysis provide compelling evidence that these environmental isolates are the source of human infections. Isolates displayed wide-ranging virulence in macrophage and animal models. When clinical and environmental isolates with indistinguishable MLST profiles were compared, environmental isolates were less virulent. Taken together, our studies reveal an environmental source and risk of C. gattii to HIV/AIDS patients with implications for the >1,000,000 cryptococcal infections occurring annually for which the causative isolate is rarely assigned species status. Thus, the C. gattii global health burden could be more substantial than currently appreciated.

The environmentally-acquired human pathogen C. gattii is responsible for ongoing and expanding outbreaks in the Western United States and Canada. C. gattii comprises four distinct molecular types: VGI, VGII, VGIII, and VGIV. Molecular types VGI, VGII, and VGIII have been isolated from patients and animals throughout the Western US. The Pacific Northwest and Canadian outbreak is primarily caused by C. gattii VGII. VGIII is responsible for ongoing infections in HIV/AIDS patients in Southern California. However, only two environmental C. gattii isolates have ever been identified from the Californian environment: CBS7750 (VGII) and WM161 (VGIII). We sought to collect environmental samples from areas that had confirmed reports of clinical or veterinary infections. Here we report the isolation of C. gattii VGI and VGIII from environmental soil and tree samples. C. gattii isolates were obtained from three novel tree species: Canary Island pine, American sweetgum, and a Pohutukawa tree. Genetic analysis provides robust evidence that these environmental isolates are the source of human infections.

Galleria mellonella model identifies highly virulent strains among all major molecular types of Cryptococcus gattii

Cryptococcosis is mainly caused by Cryptococcus neoformans. However, the number of cases due to C. gattii is increasing, affecting mainly immunocompetent hosts. C. gattii is divided into four major molecular types, VGI to VGIV, which differ in their host range, epidemiology, antifungal susceptibility and geographic distribution. Besides studies on the Vancouver Island outbreak strains, which showed that the subtype VGIIa is highly virulent compared to the subtype VGIIb, little is known about the virulence of the other major molecular types. To elucidate the virulence potential of the major molecular types of C. gattii, Galleria mellonella larvae were inoculated with ten globally selected strains per molecular type. Survival rates were recorded and known virulence factors were studied. One VGII, one VGIII and one VGIV strain were more virulent (p <0.05) than the highly virulent Vancouver Island outbreak strain VGIIa (CDCR265), 11 (four VGI, two VGII, four VGIII and one VGIV) had similar virulence (p >0.05), 21 (five VGI, five VGII, four VGIII and seven VGIV) were less virulent (p <0.05) while one strain of each molecular type were avirulent. Cell and capsule size of all strains increased markedly during larvae infection (p <0.001). No differences in growth rate at 37°C were observed. Melanin synthesis was directly related with the level of virulence: more virulent strains produced more melanin than less virulent strains (p <0.05). The results indicate that all C. gattii major molecular types exhibit a range of virulence, with some strains having the potential to be more virulent. The study highlights the necessity to further investigate the genetic background of more and less virulent strains in order to recognize critical features, other than the known virulence factors (capsule, melanin and growth at mammalian body temperature), that maybe crucial for the development and progression of cryptococcosis.

Development of an aerosol model of Cryptococcus reveals humidity as an important factor affecting the viability of Cryptococcus during aerosolization

Cryptococcus is an emerging global health threat that is annually responsible for over 1,000,000 infections and one third of all AIDS patient deaths. There is an ongoing outbreak of cryptococcosis in the western United States and Canada. Cryptococcosis is a disease resulting from the inhalation of the infectious propagules from the environment. The current and most frequently used animal infection models initiate infection via liquid suspension through intranasal instillation or intravenous injection. These models do not replicate the typically dry nature of aerosol exposure and may hinder our ability to decipher the initial events that lead to clearance or the establishment of infection. We have established a standardized aerosol model of murine infection for the human fungal pathogen Cryptococcus. Aerosolized cells were generated utilizing a Collison nebulizer in a whole-body Madison Chamber at different humidity conditions. The aerosols inside the chamber were sampled using a BioSampler to determine viable aerosol concentration and spray factor (ratio of viable aerosol concentration to total inoculum concentration). We have effectively delivered yeast and yeast-spore mixtures to the lungs of mice and observed the establishment of disease. We observed that growth conditions prior to exposure and humidity within the Madison Chamber during exposure can alter Cryptococcus survival and dose retained in mice.

The persistence of multifocal colonisation by a single ABC genotype of Candida albicans may predict the transition from commensalism to infection

Candida albicans is a common member of the human microbiota and may cause invasive disease in susceptible populations. Several risk factors have been proposed for candidaemia acquisition. Previous Candida multifocal colonisation among hospitalised patients may be crucial for the successful establishment of candidaemia. Nevertheless, it is still not clear whether the persistence or replacement of a single clone of C. albicans in multiple anatomical sites of the organism may represent an additional risk for candidaemia acquisition. Therefore, we prospectively evaluated the dynamics of the colonising strains of C. albicans for two groups of seven critically ill patients: group I included patients colonised by C. albicans in multiple sites who did not develop candidaemia and group II included patients who were colonised and who developed candidaemia. ABC and microsatellite genotyping of 51 strains of C. albicans revealed that patients who did not develop candidaemia were multiply colonised by at least two ABC genotypes of C. albicans, whereas candidaemic patients had highly related microsatellites and the same ABC genotype in colonising and bloodstream isolates that were probably present in different body sites before the onset of candidaemia.

Global Molecular Epidemiology of Cryptococcus neoformans and Cryptococcus gattii: An Atlas of the Molecular Types

Cryptococcosis is a fungal disease affecting more than one million people per year worldwide. The main etiological agents of cryptococcosis are the two sibling species Cryptococcus neoformans and Cryptococcus gattii that present numerous differences in geographical distribution, ecological niches, epidemiology, pathobiology, clinical presentation and molecular characters. Genotyping of the two Cryptococcus species at subspecies level supplies relevant information to understand how this fungus has spread worldwide, the nature of its population structure, and how it evolved to be a deadly pathogen. At present, nine major molecular types have been recognized: VNI, VNII, VNB, VNIII, and VNIV among C. neoformans isolates, and VGI, VGII, VGIII, and VGIV among C. gattii isolates. In this paper all the information available in the literature concerning the isolation of the two Cryptococcus species has been collected and analyzed on the basis of their geographical origin, source of isolation, level of identification, species, and molecular type. A detailed analysis of the geographical distribution of the major molecular types in each continent has been described and represented on thematic maps. This study represents a useful tool to start new epidemiological surveys on the basis of the present knowledge.

Cryptococcus gattii, no longer an accidental pathogen?

Cryptococcus gattii is an environmentally occurring pathogen that is responsible for causing cryptococcosis marked by pneumonia and meningoencephalitis in humans and animals. C. gattii can form long-term associations with trees and soil resulting in the production of infectious propagules (spores and desiccated yeast). The ever expanding reports of clinical and environmental isolation of C. gattii in temperate climates strongly imply C. gattii occurs world-wide. The key ability of yeast and spores to enter, survive, multiply, and exit host cells and to infect immunocompetent hosts distinguishes C. gattii as a primary pathogen and suggest evolution of C. gattii pathogenesis as a result of interaction with plants and other organisms in its environmental niche. Here we summarize the historical literature on C. gattii and recent literature supporting the world-wide occurrence of the primary pathogen C. gattii.

Cryptococcus spp isolated from dust microhabitat in Brazilian libraries

BACKGROUND

The Cryptococcus spp is currently composed of encapsulated yeasts of cosmopolitan distribution, including the etiological agents of cryptococcosis. The fungus are found mainly in substrates of animal and plant origin. Human infection occurs through inhalation of spores present in the environment.

METHODS

Eighty-four swab collections were performed on dust found on books in three libraries in the city of Cuiabá, state of Mato Grosso, Brazil. The material was seeded in Sabouraud agar and then observed for characteristics compatible with colonies with a creamy to mucous aspect; the material was then isolated in birdseed (Niger) agar and cultivated at a temperature of 37°C for 5 to 7 days. Identification of isolated colonies was performed by microscopic observation in fresh preparations dyed with India ink, additional tests performed on CGB (L-canavanine glycine bromothymol blue), urea broth, and carbohydrate assimilation tests (auxanogram).

RESULTS

Of the 84 samples collected from book dust, 18 (21.4%) were positive for Cryptococcus spp totalizing 41 UFC's. The most frequently isolated species was C. gattii 15 (36.6%); followed by C. terreus, 12 (29.3%); C. luteolus 4 (9.8%); C. neoformans, and C. uniguttulatus 3 (7.3%), and C. albidus and C. humiculus with 2 (4.6%) of the isolates.

CONCLUSION

The high biodiversity of the yeasts of the Cryptococcus genus, isolated from different environmental sources in urban areas of Brazil suggests the possibility of individuals whose immune systems have been compromised or even healthy individuals coming into sources of fungal propagules on a daily bases throughout their lives. This study demonstrates the acquisition possible of cryptococcosis infection from dust in libraries.

Cryptococcus gattii comparative genomics and transcriptomics: a NIH/NIAID White Paper

Cryptococcus gattii is an emerging global pathogen. Recent reports suggest that C. gattii cryptococcosis is more common in immunocompetent as well as HIV-infected AIDS patients than earlier estimated. An ongoing outbreak of C. gattii in Vancouver, Canada, and the US Pacific Northwest has heightened public health awareness in North America. We have few clues as to what causes emergence or re-emergence of highly pathogenic strains, why C. gattii split up from its sibling pathogen C. neoformans, why it thrives in trees instead, and why immunocompetent individuals are vulnerable to this pathogen? C. gattii comprises of four distinct lineages, but the information on the genome of C. gattii is inadequate and unrepresentative as it is limited to two strains, R265 and WM276, which are MATα, serotype B, genotype VGII/VGI from Canada and Australia, respectively. There is a wide gap in knowledge about the genomes of VGIII and VGIV strains, serotype C strains, and MATa strains. The geographical representation is inadequate in the absence of strains from California, South America, Asia, and Africa. Additional obstacles to work with this pathogen are the following: (a) complex molecular typing schemes and (b) lack of functional genomics analyses. We propose to complete genome sequencing of 12 reference strains by next-generation sequencing technology and to map their transcriptomes by RNA-Seq technology. This effort would lead to new resources for the scientific community including (1) insight from additional C. gattii genomes to anchor future research studies, (2) validation of single-nucleotide polymorphisms (SNPs) for molecular typing to improve epidemiology studies, and (3) transcript analyses from strains under relevant pathogenic and non-pathogenic conditions to accelerate the discovery of proteins for diagnostics, drug targets, and vaccines.

Fatal disseminated Cryptococcus gattii infection in New Mexico

We report a case of fatal disseminated infection with Cryptococcus gattii in a patient from New Mexico. The patient had no history of recent travel to known C. gattii-endemic areas. Multilocus sequence typing revealed that the isolate belonged to the major molecular type VGIII. Virulence studies in a mouse pulmonary model of infection demonstrated that the strain was less virulent than other C. gattii strains. This represents the first documented case of C. gattii likely acquired in New Mexico.

Environmental prevalence of Cryptococcus neoformans and Cryptococcus gattii in India: an update

An overview of work done to-date in India on environmental prevalence, population structure, seasonal variations and antifungal susceptibility of Cryptococcus neoformans and Cryptococcus gattii is presented. The primary ecologic niche of both pathogens is decayed wood in trunk hollows of a wide spectrum of host trees, representing 18 species. Overall, C. neoformans showed a higher environmental prevalence than that of C. gattii which was not found in the avian habitats. Apart from their arboreal habitat, both species were demonstrated in soil and air in close vicinity of their tree hosts. In addition, C. neoformans showed a strong association with desiccated avian excreta. An overwhelming number of C. neoformans strains belonged to genotype AFLP1/VNI, var. grubii (serotype A), whereas C. gattii strains were genotype AFLP4/VGI, serotype B. All of the environmental strains of C. neoformans and C. gattii were mating type α (MATα). Contrary to the Australian experience, Eucalyptus trees were among the epidemiologically least important and, therefore, the hypothesis of global spread of C. gattii through Australian export of infected Eucalyptus seeds is rebutted. Reference is made to long-term colonization of an abandoned, old timber beam of sal wood (Shorea robusta) by a melanin positive (Mel(+)) variant of Cryptococcus laurentii that was pathogenic to laboratory mice.

Antifungal susceptibility, enzymatic activity, PCR-fingerprinting and ITS sequencing of environmental Cryptococcus laurentii isolates from Uberaba, Minas Gerais, Brazil

Cryptococcus laurentii has been classically considered a saprophytic species, although several cases of human infection have been already reported. This study aimed to evaluate the phospholipase, proteinase and hemolysins activity, the antifungal susceptibility profile, the genetic variability by M13 and (GACA)(4) fingerprinting and the internal transcribe spacer (ITS) sequencing of 38 C. laurentii isolates recovered from captive bird droppings and surrounding hospital areas. All of them exhibited phospholipase activity, while the hemolytic activity was evidenced in 34 (89.4%) isolates. None of them exhibited proteinase activity. Twenty-seven isolates (71.1%) presented susceptibility dose dependent to fluconazole. Most isolates (94.7%) were susceptible to voriconazole, while one (2.65%) was resistant to this drug. Twenty-one (55.3%) isolates showed reduced susceptibility to itraconazole while nine (23.7%) were resistant. Three (7.9%) and five (13.1%) isolates exhibited resistance to ketoconazole and amphotericin B, respectively. Most C. laurentii fingerprinting obtained with M13 and (GACA)(4) showed high heterogeneity. By using the two primers, seven (18.4%) isolates grouped as A (CL2, CL7, and CL8), B (CL35, CL38) and C (CL29, CL30) with 100% similarity. Different from most variable surrounding hospital isolates, all but one of the pet shops strains clustered with the two primers, although they had been recovered from different neighborhoods. All isolates were identified as C. laurentii phylogenetic group I by ITS sequencing. Thus, the presence of virulence factors, a decreased antifungal susceptibility and a heterogeneous molecular pattern of the C. laurentii isolates here described suggests this species can be a potential pathogen in the context of the immunocompromised population.

Cryptococcus gattii: where do we go from here?

Infections caused by the emerging pathogen Cryptococcus gattii are increasing in frequency in North America. During the past decade, interest in the pathogen has continued to grow, not only in North America but also in other areas of the world where infections have recently been documented. This review synthesizes existing data and raises issues that remain to be addressed.