Susceptibility to antifungal agents and genotypes of Brazilian clinical and environmental Cryptococcus gattii strains

Silva, Dayane C.; Martins, Marilena dos Anjos; Szeszs, Maria Walderez; Bonfietti, Lucas Xavier; Matos, Dulcilena; Melhem, Márcia de Souza Carvalho

doi:10.1016/j.diagmicrobio.2011.11.016

Cited by 32 publications

(27 citation statements)

References 61 publications

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“…VGII is very common in the PNW, Australia, and India and has recently been found in clinical and environmental isolates from Brazil [55, 89]. In Brazil, more isolates (94%) in the clinical environment were found to be VGII than VGI (6%); but, the proportion of VGI (25%) increased in the non-clinical isolates collected in soil and bird droppings, suggesting a higher virulence of VGII in mammalian hosts [90]. …”

Section: Environmental Distribution Of C Gattiimentioning

confidence: 99%

Cryptococcus gattii, No Longer an Accidental Pathogen?

Springer

Phadke

Billmyre

et al. 2012

Curr Fungal Infect Rep

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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.

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Section: Environmental Distribution Of C Gattiimentioning

confidence: 99%

Cryptococcus gattii, No Longer an Accidental Pathogen?

Springer

Phadke

Billmyre

et al. 2012

Curr Fungal Infect Rep

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“…In 2012, Silva et al . found MIC values ranging from 1 to 32 mg l −1 for C. deuterogattii (VGII). Likewise, Trilles et al .…”

Section: Discussionmentioning

confidence: 99%

Evaluation of antifungal combination against Cryptococcus spp.

Reichert-Lima

Busso-Lopes

Lyra

et al. 2016

Mycoses

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The second cause of death among systemic mycoses, cryptococcosis treatment represents a challenge since that 5-flucytosine is not currently available in Brazil. Looking for alternatives, this study evaluated antifungal agents, alone and combined, correlating susceptibility to genotypes. Eighty Cryptococcus clinical isolates were genotyped by URA5 gene restriction fragment length polymorphism. Antifungal susceptibility was assessed following CLSI-M27A3 for amphotericin (AMB), 5-flucytosine (5FC), fluconazole (FCZ), voriconazole (VRZ), itraconazole (ITZ) and terbinafine (TRB). Drug interaction chequerboard assay evaluated: AMB + 5FC, AMB + FCZ, AMB + TRB and FCZ + TRB. Molecular typing divided isolates into 14 C. deuterogattii (VGII) and C. neoformans isolates were found to belong to genotype VNI (n = 62) and VNII (n = 4). C. neoformans VNII was significantly less susceptible than VNI (P = 0.0407) to AMB; C. deuterogattii was significantly less susceptible than VNI and VNII to VRZ (P < 0.0001). C. deuterogattii was less susceptible than C. neoformans VNI for FCZ (P = 0.0170), ITZ (P < 0.0001) and TRB (P = 0.0090). The combination FCZ + TRB showed 95.16% of synergistic effect against C. neoformans genotype VNI isolates and all combinations showed 100% of synergism against genotype VNII isolates, suggesting the relevance of cryptococcal genotyping as it is widely known that the various genotypes (now species) have significant impact in antifungal susceptibilities and clinical outcome. In difficult-to-treat cryptococcosis, terbinafine and different antifungal combinations might be alternatives to 5FC.

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“…Molecular and epidemiological investigations revealed the Vancouver Island, BC outbreak was attributed to a novel and seemingly hypervirulent VGIIa genotype [7,20,22]; moreover, the recent PNW outbreak was attributed to an additional novel genotype, VGIIc [23]. These apparent new genotypes (VGIIa and VGIIc), are responsible for greater than 90% of C. gattii infections in the BC/PNW region [7].…”

Section: Discussionmentioning

confidence: 99%

Real-time PCR assays for genotyping of Cryptococcus gattii in North America

et al. 2014

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BackgroundCryptococcus gattii has been the cause of an ongoing outbreak starting in 1999 on Vancouver Island, British Columbia and spreading to mainland Canada and the US Pacific Northwest. In the course of the outbreak, C. gattii has been identified outside of its previously documented climate, habitat, and host disease. Genotyping of C. gattii is essential to understand the ecological and geographical expansion of this emerging pathogen.MethodsWe developed and validated a mismatch amplification mutation assay (MAMA) real-time PCR panel for genotyping C. gattii molecular types VGI-VGIV and VGII subtypes a,b,c. Subtype assays were designed based on whole-genome sequence of 20 C. gattii strains. Publically available multilocus sequence typing (MLST) data from a study of 202 strains was used for the molecular type (VGI-VGIV) assay design. All assays were validated across DNA from 112 strains of diverse international origin and sample types, including animal, environmental and human.ResultsValidation revealed each assay on the panel is 100% sensitive, specific and concordant with MLST. The assay panel can detect down to 0.5 picograms of template DNA.ConclusionsThe (MAMA) real-time PCR panel for C. gattii accurately typed a collection of 112 diverse strains and demonstrated high sensitivity. This is a time and cost efficient method of genotyping C. gattii best suited for application in large-scale epidemiological studies.

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Susceptibility to antifungal agents and genotypes of Brazilian clinical and environmental Cryptococcus gattii strains

Cited by 32 publications

References 61 publications

Cryptococcus gattii, No Longer an Accidental Pathogen?

Cryptococcus gattii, No Longer an Accidental Pathogen?

Evaluation of antifungal combination against Cryptococcus spp.

Real-time PCR assays for genotyping of Cryptococcus gattii in North America

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