Aislamiento de Cryptococcus gattii serotipo B a partir de detritos de Eucalyptus spp. en Colombia.

Abstract

Introducción. Cryptococcus gattii serotipo B ha sido asociado con diferentes especies de árboles en regiones tropicales y subtropicales. Este serotipo es el segundo de mayor importancia clínica en Colombia, pero no se había recuperado del ambiente en ninguno de los estudios realizados por nuestro grupo. Objetivo. Para establecer la presencia y distribución de las especies del complejo C. neoformans, especialmente del serotipo B, y determinar algunas características fenotípicas relacionadas con la virulencia de los aislamientos recuperados, se diseñó un muestreo de material vegetal en un bosque de piso térmico frío del departamento de Cundinamarca. Materiales y métodos. Durante febrero y marzo de 2003 se realizaron 4 muestreos en el bosque y se tomaron 167 muestras de detritos de eucaliptos y 28 muestras de otras especies de árboles, las cuales se procesaron empleando el método convencional de extracción y siembra en medio selectivo. Se determinó el tamaño celular y capsular en los filtrados, el crecimiento a 37°C, la virulencia en un modelo animal y la pareja sexual por PCR. Resultados. Se aisló C. gattii serotipo B de 46 muestras de eucaliptos (27,5%). El tamaño celular en el extracto estuvo entre 3,10 y 4,15 µm y el tamaño capsular entre 0,30 y 0,46 µm. Los 46 aislamientos crecieron a 37°C, pero ninguno de los dos aislamientos empleados causó la muerte de los animales inoculados durante los 70 días de observación. Todos los aislamientos fueron pareja sexual a. Conclusiones. Este estudio es el primer informe sobre el aislamiento de C. gattii, serotipo B, pareja sexual a, en Colombia a partir de detritos de eucaliptos. Palabras clave:Cryptococcus, hábitat, Eucalyptus, fenotipo, virulencia. Isolation of Cryptococcus gattii serotype B from detritus of Eucalyptus trees in ColombiaIntroduction. Cryptococcus gattii serotype B has been associated with several species of trees in tropical and subtropical regions. Serotype B has been found to be the second most frequently isolated from patients in Colombia, but it has not been isolated from the environment. Therefore, a study was designed to sample plant material from a forest in the province of Cundinamarca, with the aim of establishing the presence and distribution of the C. neoformans complex, specially serotype B. In addition, isolates were evaluated for several phenotypic characteristics associated with virulence. Methodology. During February and March, 2003, 4 separate sample collections were made. One hundred sixty-seven samples were collected from detritus of eucalyptus and 28 samples from other species of trees. All were processed using the conventional procedure and plated on selective media. The following parameters were measured: cellular and capsular sizes in the filtrates, growth at 37°C, virulence in a mouse animal model system, and mating type as detected by PCR. Results. Cryptococcus gattii serotype B was isolated from 46 eucalyptus samples (27.5%). The cellular size in the filtrates ranged from 3.10 to 4.15 µm and the capsular size from 0.30 and 0.46 µ...

Primer aislamiento ambiental de Cryptococcus gattii de serotipo B, en Cúcuta, Colombia

“…Compared with other studies where C. gattii had been found in 27.5% and 99% of the sampled trees, and the recovery was between 50 and 15 x 10 6 cfu/g of sample (16,33) and C. neoformans had been recovered among 7.9% and 14% of the samples, with a recovery between 50 and 1x10 7 cfu/g of sample (33,34), in our study, only 0.07% of the samples processed were positive for C. neoformans/C. gattii species complex.…”

“…In addition, the findings of this study increase the number of reports of the recovering of C. gattii from the environment, although it was not possible to associate the isolate with a specific tree species, because the isolate was recovered from soil, in contrast to previous studies of ecological reservoirs of C. gattii, in which associations between the yeast and different trees species had been found due to the recovering of the yeast from vegetable parts (14)(15)(16)(17)27,28). However, our results show that the soil is the sample that is harboring the fungus, while the other tree material was negative, possibly because most of the samples were taken from soil (82.8%), but suggesting that the soil is one of the main reservoirs of colonization for this pathogen, and therefore, the fungus may be interacting with non-vertebrate hosts as nematodes and amoebae, as suggested by Casadevall et al (29).…”

“…On the other hand, C. gattii serotype B has been isolated several times from different environmental sources in the world (14)(15)(16)(17); for that reason, the aim of this work was to carry out an extensive environmental sampling survey in different areas of the city of Cúcuta, in an attempt to isolate C. gattii serotype B from different trees, to determine its circulation and to expand our knowledge about the ecology and the epidemiology of this pathogenic yeast in our country. …”

Cryptococcus gattii Infections

“…Molecular types VGI and VGII are those most commonly associated with a wide variety of tree species (74,110,126). VGIII has been isolated from eucalypts and almond trees in Colombia and other trees in the greater Los Angeles area of California (74,(126)(127)(128), and both mating types of VGIV were found in the same two species in Colombia (127) and Tunisia (112).…”

Refractory and/or Relapsing Cryptococcosis Associated with Acquired Immune Deficiency Syndrome: Clinical Features, Genotype, and Virulence Factors of Cryptococcus spp. Isolates

“…neoformans/Dα and Da, and C. gattii/B/ Cα and B/Ca. [14][15][16][17][18] Molecular typing was performed by PCR fingerprinting using primers for the specific sequence of the minisatellite (GACA) 4 . 19 Internal transcribed spacer sequence analysis for the identification of clinical isolates.…”