ABSTRACT
The small molecule (molecular mass <900 Daltons) composition of extracellular vesicles (EVs) produced by the pathogenic fungus Cryptococcus gattii is unknown, which limits the understanding of the functions of cryptococcal EVs. In this study, we analyzed the composition of small molecules in samples obtained from solid cultures of C. gattii by a combination of chromatographic and spectrometric approaches, and untargeted metabolomics. This analysis revealed previously unknown components of EVs, including small peptides with known biological functions in other models. The peptides found in C. gattii EVs had their chemical structure validated by chemical approaches and comparison with authentic standards, and their functions tested in a Galleria mellonella model of cryptococcal infection. One of the vesicular peptides (isoleucine-proline-isoleucine, Ile-Pro-Ile) improved the survival of G. mellonella lethally infected with C. gattii or C. neoformans. These results indicate that small molecules exported in EVs are biologically active in Cryptococcus. Our study is the first to characterize a fungal EV molecule inducing protection, pointing to an immunological potential of extracellular peptides produced by C. gattii.
Subject(s)
Cryptococcosis/metabolism , Cryptococcus gattii/physiology , Extracellular Vesicles/chemistry , Extracellular Vesicles/metabolism , Host-Pathogen Interactions , Invertebrates , Animals , Computational Biology/methods , Cryptococcosis/microbiology , Extracellular Vesicles/ultrastructure , Metabolomics/methods , Molecular Structure , PeptidesABSTRACT
Cryptococcus gattii predominantly causes central nervous system and pulmonary infection in both immunocompromised and immunocompetent patients with substantial morbidity. We report a case of rapidly fatal meningitis by C. gattii in an HIV-non-infected man with CD4 lymphopenia who tested negative for cryptococcal antigen. This case may serve as an alert to its wider occurrence and less explored risk factors.
Subject(s)
Antigens, Fungal/analysis , Cryptococcosis/diagnosis , Cryptococcosis/pathology , Cryptococcus gattii/isolation & purification , Meningitis/diagnosis , Meningitis/pathology , Adult , CD4-Positive T-Lymphocytes/immunology , Cryptococcus gattii/immunology , Fatal Outcome , Humans , Lymphopenia/complications , Male , Meningitis/microbiologyABSTRACT
Cryptococcus neoformans and Cryptococcus gatti both cause infection in immunocompromised patients. We report a case of meningitis with C. gatti in an AIDS patient. This case to our knowledge is the first case of C. gatti being reported from Sikkim (North East India).
ABSTRACT
We report a case of an immunocompetent Peruvian patient from the Andes with a one-month history of meningoencephalitis. Cryptococcus gattii was identified from a cerebrospinal fluid culture through assimilation of D-proline and D-tryptophan as the single nitrogen source. Initially, the patient received intravenous antifungal therapy with amphotericin B. The patient was discharged 29 days after hospitalization and continued with oral fluconazole treatment for ten weeks. During this period, the patient showed clinical improvement with slight right-side residual weakness. Through this case report, we confirm the existence of this microorganism as an infectious agent in Peru.
Nós reportamos o caso de um paciente peruano immunocompetente proveniente dos Andes com história de um mês com meningoencefalite. Foi identificado o Cryptococcus gattii na cultura de liquido cerebrospinal através da assimilação de D-prolina e D-tryptofano como fonte única de nitrogênio. Inicialmente, o paciente recebeu tratamento antifúngico intravenoso com amfotericina B. O paciente foi liberado 29 dias depois da hospitalização, seguindo tratamento oral durante 10 semanas com fluconazol. Durante este período, o paciente apresentou melhoria clinica e uma leve fraqueza residual direita. Com o reporte do caso, nós confirmamos a existência desse microorganismo como agente infeccioso em nosso país.
Subject(s)
Humans , Male , Middle Aged , Cryptococcosis/diagnosis , Cryptococcus gattii/isolation & purification , Meningoencephalitis/microbiology , Amphotericin B/therapeutic use , Antifungal Agents/therapeutic use , Cryptococcosis/drug therapy , Fluconazole/therapeutic use , Meningoencephalitis/drug therapy , PeruABSTRACT
Este trabalho identificou variedades de Cryptococcus neoformans e avaliou a suscetibilidade a antifúngicos pelo protocolo M27-A2 do National Committee for Clinical Laboratory Standards em isolados de 35 pacientes do Hospital Escola da Universidade Federal do Triângulo Mineiro. A variedade gatti foi identificada em 11.4 por cento (nº = 4) dos casos. A concentração inibitória mínima (mg/ml) dos isolados de Cryptococcus neoformans neoformans variou de 0,062 - 2,000 (anfotericina B), 0,250 - 8,000 (fluconazol), 0,062 - 1,000 (itraconazol) e 0,125 - 1,000 (cetoconazol). A variedade gattii apresentou concentração inibitória mínima de 0,125 - 2,000 (anfotericina B), 0,250 - 16,00 (fluconazol), 0,062 - 1,000 (itraconazol) e 0,125 - 4,000 (cetoconazol). Detectaram-se 2 isolados resistentes ao itraconazol e 2 a anfotericina B (1 isolado de cada variedade por antifúngico). Os dados mostram a importância da determinação da variedade e da concentração inibitória mínima de isolados de Cryptococcus neoformans para monitorar o desenvolvimento de resistência e possibilitar uma terapia mais adequada na criptococose.
This study identified Cryptococcus neoformans varieties isolated from 35 patients at teaching hospital of the Federal University of the Triângulo Mineiro and evaluated the susceptibility to antifungal agents among these samples using the protocol M27-A2 from the National Committee for Clinical Laboratory Standards. The gattii variety was identified in 11.4 percent of the cases (n = 4). The minimum inhibitory concentration (mg/ml) of Cryptococcus neoformans neoformans isolates ranged from 0.062 to 2.000 (amphotericin B), 0.250 to 8.000 (fluconazole), 0.062 to 1.000 (itraconazole) and 0.125 to 1.000 (ketoconazole). The gattii variety presented a minimum inhibitory concentration range of 0.125 to 2.000 (amphotericin B), 0.250 to 16.00 (fluconazole), 0.062 to 1.000 (itraconazole) and 0.125 to 4.000 (ketoconazole). Two isolates resistant to itraconazole and two resistant to amphotericin B (one isolate of each variety per antifungal agent) were found. These data show the importance of determining the variety and minimum inhibitory concentration of Cryptococcus neoformans isolates, in order to monitor resistance development and enable better treatment for cryptococcosis.
