Dataset Information

Antifungal susceptibility of clinical Cryptococcus gattii isolates from Colombia varies among molecular types.

ABSTRACT: Cryptococcosis by Cryptococcus gattii is endemic in Colombia, affecting mostly immunocompetent hosts. Since antifungal susceptibility differs between molecular types of cryptococcal isolates, as reported elsewhere, the aim of this study was to determine if 42 Colombian clinical isolates, VGI, VGII and VGIII, differ in the susceptibility to commonly used antifungals, using Sensititre plates. Among the molecular types, six non-wild type isolates to fluconazole, voriconazole, and 5-flucytosine, were identified. Besides, VGI and VGII were less susceptible to 5-flucytosine and azoles, respectively, than other molecular types. These findings support the applicability of practicing susceptibility testing, which could better guide treatment in cryptococcosis.

Lay summary

Cryptococcosis gattii affects immunocompetent people. For a correct treatment, antifungal susceptibility testing is essential. This study shows differences in the susceptibility to commonly used antimycotics among genotypes of Colombian clinical C. gattii isolates, some of which are non-wild-type.

SUBMITTER: Firacative C

PROVIDER: S-EPMC8757315 | biostudies-literature | 2021 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Antifungal susceptibility of clinical Cryptococcus gattii isolates from Colombia varies among molecular types.

Firacative Carolina C Escandón Patricia P

Medical mycology 20211101 11

Cryptococcosis by Cryptococcus gattii is endemic in Colombia, affecting mostly immunocompetent hosts. Since antifungal susceptibility differs between molecular types of cryptococcal isolates, as reported elsewhere, the aim of this study was to determine if 42 Colombian clinical isolates, VGI, VGII and VGIII, differ in the susceptibility to commonly used antifungals, using Sensititre plates. Among the molecular types, six non-wild type isolates to fluconazole, voriconazole, and 5-flucytosine, wer ...[more]

PMID: 34264298

Similar Datasets

Project description:Cryptococcus-macrophage interaction is crucial in the development of cryptococcocal diseases. C. neoformans and C. gattii are major pathogenic species that occupy different niches and cause different clinical manifestations. However, the differences of macrophage interaction among these species in affecting different disease outcomes and immune responses have not been clearly addressed. Here, we examined the macrophage uptake rates, intracellular loads and intracellular proliferation rates of C. neoformans and C. gattii clinical isolates from Thailand and analyzed the effect of those interactions on fungal burdens and host immune responses. C. neoformans isolates showed a higher phagocytosis rate but lower intracellular proliferation rate than C. gattii. Indeed, the high intracellular proliferation rate of C. gattii isolates did not influence the fungal burdens in lungs and brains of infected mice, whereas infection with high-uptake C. neoformans isolates resulted in significantly higher brain burdens that associated with reduced survival rate. Interestingly, alveolar macrophages of mice infected with high-uptake C. neoformans isolates showed distinct patterns of alternatively activated macrophage (M2) gene expressions with higher Arg1, Fizz1, Il13 and lower Nos2, Ifng, Il6, Tnfa, Mcp1, csf2 and Ip10 transcripts. Corresponding to this finding, infection with high-uptake C. neoformans resulted in enhanced arginase enzyme activity, elevated IL-4 and IL-13 and lowered IL-17 in the bronchoalveolar lavage. Thus, our data suggest that the macrophage interaction with C. neoformans and C. gattii may affect different disease outcomes and the high phagocytosis rates of C. neoformans influence the induction of type-2 immune responses that support fungal dissemination and disease progression. Abbreviation: Arg1: Arginase 1; BAL: Bronchoalveolar lavage; CCL17: Chemokine (C-C motif) ligand 17; CNS: Central nervous system; CSF: Cerebrospinal fluid; Csf2: Colony-stimulating factor 2; Fizz1: Found in inflammatory zone 1; HIV: Human immunodeficiency virus; ICL: Intracellular cryptococcal load; Ifng: Interferon gamma; Ip10: IFN-g-inducible protein 10; IPR: Intracellular proliferation rate; Mcp1: Monocyte chemoattractant protein 1; Nos2: Nitric oxide synthase 2; PBS: Phosphate-Buffered Saline; Th: T helper cell; Tnfa: Tumor necrosis factor alpha.

Project description:The pathogenic species of Cryptococcus are a major cause of mortality owing to severe infections in immunocompromised as well as immunocompetent individuals. Although antifungal treatment is usually effective, many patients relapse after treatment, and in such cases, comparative analyses of the genomes of incident and relapse isolates may reveal evidence of determinative, microevolutionary changes within the host. Here, we analyzed serial isolates cultured from cerebrospinal fluid specimens of 18 South African patients with recurrent cryptococcal meningitis. The time between collection of the incident isolates and collection of the relapse isolates ranged from 124 days to 290 days, and the analyses revealed that, during this period within the patients, the isolates underwent several genetic and phenotypic changes. Considering the vast genetic diversity of cryptococcal isolates in sub-Saharan Africa, it was not surprising to find that the relapse isolates had acquired different genetic and correlative phenotypic changes. They exhibited various mechanisms for enhancing virulence, such as growth at 39°C, adaptation to stress, and capsule production; a remarkable amplification of ERG11 at the native and unlinked locus may provide stable resistance to fluconazole. Our data provide a deeper understanding of the microevolution of Cryptococcus species under pressure from antifungal chemotherapy and host immune responses. This investigation clearly suggests a promising strategy to identify novel targets for improved diagnosis, therapy, and prognosis.IMPORTANCE Opportunistic infections caused by species of the pathogenic yeast Cryptococcus lead to chronic meningoencephalitis and continue to ravage thousands of patients with HIV/AIDS. Despite receiving antifungal treatment, over 10% of patients develop recurrent disease. In this study, we collected isolates of Cryptococcus from cerebrospinal fluid specimens of 18 patients at the time of their diagnosis and when they relapsed several months later. We then sequenced and compared the genomic DNAs of each pair of initial and relapse isolates. We also tested the isolates for several key properties related to cryptococcal virulence as well as for their susceptibility to the antifungal drug fluconazole. These analyses revealed that the relapsing isolates manifested multiple genetic and chromosomal changes that affected a variety of genes implicated in the pathogenicity of Cryptococcus or resistance to fluconazole. This application of comparative genomics to serial clinical isolates provides a blueprint for identifying the mechanisms whereby pathogenic microbes adapt within patients to prolong disease.

Dataset Information

Antifungal susceptibility of clinical Cryptococcus gattii isolates from Colombia varies among molecular types.

Lay summary

Publications

Antifungal susceptibility of clinical Cryptococcus gattii isolates from Colombia varies among molecular types.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets