Candida auris: a global pathogen that has taken root in Colombia

Candida auris has been recognized as an emerging multidrug-resistant pathogen with a significant public health burden, causing cases of invasive infection and colonization due to its persistence on inanimate surfaces, ability to colonize skin of some patients, and high transmissibility in healthcare settings. The first sporadic report of the isolation of this species from the ear canal of a patient in Asia was in 2009 and reports from other regions of the world soon followed. However, it was not until 2015 that global epidemiological alerts were communicated as a result of an increasing number of reports of invasive infections caused by C. auris in several countries. Colombia was soon added to this list in 2016 after an unusual increase in the number of C. haemulonii isolates was reported, later confirmed as C. auris. Since the issuing of a national alert by the Colombian National Institute of Health together with the Ministry of Health in 2016, the number of cases reported reached over 2,000 by 2022. Colombian isolates have not shown pan resistance to available antifungals, unlike C. auris strains reported in other regions of the world, which leaves patients in Colombia with therapeutic options for these infections. However, increasing fluconazole resistance is being observed. Whole-genome sequencing of Colombian C. auris isolates has enhanced molecular epidemiological data, grouping Colombian isolates in clade IV together with other South American isolates. Data from Colombia showed that public health authorities, scientific community, and the general public need to be aware of fungal diseases as they present an often-deadly threat to patients.

Candida auris ha sido reconocido como un agente patógeno multirresistente emergente con una carga significativa en la salud pública. Genera casos de infección invasiva y colonización debido a su persistencia en superficies inanimadas, su capacidad para colonizar fácilmente la piel de algunos pacientes y su alta transmisibilidad en el ambiente hospitalario. El primer reporte esporádico de esta especie fue en Asia en el 2009 cuando se realizó su aislamiento a partir del conducto auditivo de un paciente, y pronto le siguieron reportes en otras regiones del mundo. Sin embargo, no fue hasta 2015 que se conocieron las alertas epidemiológicas a nivel mundial debido a un aumento en el número de casos de infecciones causadas por C. auris en varios países. Colombia se sumó a la lista en 2016 luego de un aumento inusual en el número de aislamientos de C. haemulonii informados, que luego se confirmaron como C. auris. Desde que el Instituto Nacional de Salud junto con el Ministerio de Salud emitieron la Alerta Nacional en el 2016, el número de casos reportados superó los 2.000 en el 2022. Los aislamientos colombianos no han mostrado resistencia generalizada a los antifúngicos disponibles, contrario a lo reportado para cepas de C. auris en algunas regiones del mundo, por lo que los pacientes en Colombia aún cuentan con opciones terapéuticas para estas infecciones. No obstante, se ha observado un aumento en la resistencia al fluconazol. La secuenciación del genoma completo agrupó los aislamientos colombianos en el Ciado IV, junto con otros sudamericanos de C. auris, y aportó al conocimiento de los datos epidemiológicos moleculares de esta especie. Los datos de Colombia evidencian que las autoridades de salud pública, la comunidad científica y el público en general deben ser conscientes de las enfermedades fúngicas, ya que a menudo representan una amenaza mortal para los pacientes.

Comparison of two commercial tests (Immy vs. Dynamiker) for cryptococcal capsular antigen

Abstract INTRODUCTION Lateral flow assay is an advanced method useful in the early diagnosis of cryptococcal meningitis. We aimed to compare two commercial tests for cryptococcal capsular antigen in the sera of asymptomatic patients with human immunodeficiency virus in Barranquilla, Colombia. METHODS Thawed (n=162) previously collected serums (2016-2019) were processed using IMMY and Dynamiker cryptococcal antigen lateral flow assay. RESULTS Compared to IMMY's results, Dynamiker's sensitivity, specificity, positive predictive value, negative predictive value, and kappa index were 100%, 89.9%, 48.3%, 100.0%, and 0.61, respectively. CONCLUSIONS The Dynamiker test had excellent sensitivity, acceptable specificity, and a low detection threshold for cryptococcal antigen in the tested samples.

Identificación de aislamientos de Candida auris recuperados a través de la vigilancia por laboratorio en Colombia: un reto para el diagnóstico / Identification of Candida auris isolates recovered through laboratory surveillance in Colombia: a challenge for diagnostic

Resumen Objetivo: Comparar los resultados obtenidos de diferentes sistemas de identificación de C. auris. Métodos: Análisis descriptivo con datos recopilados durante 2016-19 mediante la vigilancia nacional. Se evaluaron los resultados generados por los sistemas MicroScan, Phoenix BD, VITEK 2 y MALDI-TOF MS de instituciones hospitalarias de 843 aislamientos clínicos sospechosos de C. auris remitidos al INS y se compararon con los resultados generados de confirmación a través de MALDI- TOF MS (Bruker Daltonics) o PCR. Resultados: De los 843 aislamientos clínicos remitidos al INS, el 81,7% fueron confirmados como C. auris mediante MALDI- TOF MS o PCR en el INS y el resto, 18,3%, fueron identificados como otras especies de Candida spp. Las identificaciones correctas enviadas por los laboratorios representaron el 42,4%. MicroScan identificó C. auris principalmente como C. haemulonii, C. guilliermondii, C. albicans y C. famata; Phoenix BD, VITEK 2 y MALDI-TOF MS identificó C. auris como C. haemulonii. Discusión: Estudios señalan que C. auris exhibe una estrecha relación filogenética con C. haemulonii. Las identificaciones discrepantes pueden darse debido a que las bases de datos de los sistemas de diagnóstico son limitadas para este patógeno. Las deficiencias de los sistemas comerciales para la identificación de C. auris deben ser complementados con otros sistemas como MALDI-TOF MS o pruebas moleculares.

Abstract Objective: To compare the identification results obtained by different identification systems of C. auris isolates. Methods: A descriptive study with data collected during the years 2016-19 through surveillance. The results generated by the MicroScan, Phoenix BD, VITEK 2 and MALDI-TOF MS systems of 843 clinical isolates of C. auris submitted to the INS were evaluated and compared with the results generated from confirmation through MALDI-TOF MS (Bruker Daltonics) or PCR. Results: Out of 843 clinical isolates submitted to the INS, 81.7% were confirmed as C. auris by MALDITOF MS or PCR in the INS and the rest, 18.3%, were identified as other species of Candida spp. The correct identifications sent by the laboratories was 42.4%. MicroScan identified C. auris as C. haemulonii, C. guilliermondii, C. albicans and C. famata; Phoenix BD, VITEK 2 and MALDI-TOF MS identified C. auris as C. haemulonii. Discussion: Studies indicate that C. auris exhibits a close phylogenetic relationship with C. haemulonii. In addition, discrepant identifications may occur because the databases of diagnostic systems are limited with reference to this pathogen. The deficiencies of commercial systems for the identification of C. auris must be complemented with other systems such as MALDI-TOF MS or molecular tests.

Multilocus sequence typing (MLST) of clinical and environmental isolates of Cryptococcus neoformans and Cryptococcus gattii in six departments of Colombia reveals high genetic diversity

Abstract INTRODUCTION: The average annual incidence of cryptococcosis in Colombia is 0.23 cases per 100,000 inhabitants in the general population, and 1.1 cases per 1000 in inhabitants with Acquired Immune Deficiency Syndrome (AIDS). In addition, the causal fungus has been isolated from the environment, with serotypes A-B and C in different regions. This study aims to determine the genetic association between clinical and environmental isolates of C. neoformans/C. gattii in Colombia. METHODS: Multilocus sequence typing (MLST) was used to identify possible clones, providing information about the epidemiology, ecology, and etiology of this pathogen in Colombia. RESULTS: A total of 110 strains, both clinical (n=61) and environmental (n=49), with 21 MLST sequence types (ST) of C. neoformans (n=14STs) and C. gattii (n=7STs) were identified. The STs which shared clinical and environmental isolate sources were grouped in different geographical categories; for C. neoformans, ST93 was identified in six departments, ST77 in five departments; and for C. gattii, ST25 was identified in three departments and ST79 in two. CONCLUSIONS: High genetic diversity was found in isolates of C. neoformans/gattii by MLST, suggesting the presence of environmental sources harboring strains which may be sources of infection for humans, especially in immunocompromised patients; these data contribute to the information available in the country on the distribution and molecular variability of C. neoformans and C. gattii isolates recovered in Colombia.

Prevalence of cryptococcosis in Atlántico, department of Colombia assessed with an active epidemiological search

Abstract INTRODUCTION Cryptococcosis is the second most frequent cause of opportunistic infections in human immunodeficiency virus (HIV) patients in Colombia. We aimed to determine the prevalence of cryptococcosis in the Colombian department of Atlántico. METHODS An active search for cryptococcosis cases was conducted between 2015 and 2017 in health institutions by distributing surveys to clinicians and characterizing samples phenotypically and genotypically. RESULTS Thirty-eight cryptococcosis cases were identified (81.6% men, 76.3% HIV patients). The calculated annual prevalence was 5.08/1 million inhabitants. Cryptococcus neoformans var. grubii VNI was isolated in 34 cases. CONCLUSIONS These results provide the basis for passive surveillance of cryptococcosis.

Fatal Cryptococcus gattii genotype VGI infection in an HIV-positive patient in Barranquilla, Colombia

ABSTRACT Cryptococcosis is a major invasive fungal disease related worldwide with the AIDS population. New reports of HIV/AIDS cases to the national public health surveillance system (SIVIGILA) in Colombia have shown that there is a growing community at risk of contracting cryptococcosis throughout the country who do not have access to ART. Even though the most prevalent species Cryptococcus neoformans is mainly associated with the HIV population, we report a fatal case of cryptococcosis in an AIDS patient in Barranquilla, associated with Cryptococcus gattii VGI, isolated from blood culture.

Distribution and association between environmental and clinical isolates of Cryptococcus neoformans in Bogotá-Colombia, 2012-2015

The propagules of the fungal species Cryptococcus neoformans and C. gattii, whose varieties are distributed world wide, are the primary cause of cryptococcosis, a life threatening disease. The study of environmental and clinical isolates of Cryptococcosis is an important contribution to the epidemiology and ecology of the fungus. The aim of this work was to determine the presence of C. neoformans and C. gattii in the environment in Bogotá, Colombia’s capital city and to establish the relation between clinical and environmental isolates in the period 2012-2015. From a total of 4.116 environmental samples collected between October 2012 - March 2014, 35 were positive for C. neoformans var. grubii. From 55 cryptococcosis cases reported in Bogotá during 2012-2015, 49 isolates were recovered. From those, 94% were identified as C. neoformans var. grubii molecular type VNI; 4% as VNII and 1,2% as C. neoformans var neoformans VNIV. The 84 detected clinical and environmental isolates studied had a similarity between 49-100% according with molecular typing. The correlation between environmental and clinical samples confirms the hypothesis that patients acquire the disease from environmental exposure to the fungal propagules.

Cryptococcosis in Atlántico, Colombia: an approximation of the prevalence of this mycosis and the distribution of the etiological agent in the environment

ABSTRACTINTRODUCTION:Cryptococcosis is an invasive disease acquired by inhalation of infectious propagules from the environment. Currently, compulsory notification of the spread of this disease is not required in Colombia. However, reporting of human immunodeficiency virus (HIV)/acquired immune deficiency syndrome cases to the National Surveillance System has suggested that there is a growing population at risk of contracting cryptococcosis. Few studies have described the occurrence of cryptococcosis in Colombia. Therefore, in this study, we examined the pathology of this disease in Atlántico, Colombia and determined the distributions of Cryptococcus neoformans and Cryptococcus gattii in the environment.METHODS:Clinical samples/isolates were gathered from cases of cryptococcosis previously diagnosed at health institutions in Atlántico, and surveys were completed by clinicians. The environmental study considered 32 sampling points and three tree species, i.e., Quickstick ( Gliricidia sepium ), Almond ( Terminalia catappa ), and Pink trumpet ( Tabebuia rosea ). Environmental and clinical samples/isolates were analyzed for phenotypic and genotypic confirmation.RESULTS:From 1997-2014, 41 cases of cryptococcosis were reported. The mean patient age was 40.5 years (range: 18-63 years); 76% were men, and 78% were HIV positive. Isolation was possible in 38 cases ( C. neoformans , molecular type VNI in 37 cases and C. gattii , molecular type VGI in one case). In 2012-2014, 2,068 environmental samples were analyzed with a positivity of 0.4% ( C. neoformans , molecular type VNI) in Almond and Pink trumpet trees.CONCLUSIONS:Cryptococcus neoformans , molecular type VNI had a higher prevalence than C. gattii and was associated with human exposure and the pathogenesis of cryptococcosis in this geographical region.

Cryptococcosis in Colombian children and literature review

Cryptococcosis is reported in adults and is often acquired immune deficiency syndrome (AIDS)-associated; however, its frequency in children is low. Based on the National Survey on Cryptococcosis conducted in Colombia, an epidemiological and clinical analysis was performed on cases of the disease observed in children less than 16 years old between 1993-2010. We found 41 affected children (2.6% prevalence) from the 1,578 surveys received. The country mean annual incidence rate was 0.017 cases/100,000 children under 16 years, while in Norte de Santander the incidence rate was 0.122 cases/100,000 (p < 0.0001). The average age of infected children was 8.4 and 58.5% were male. In 46.3% of cases, a risk factor was not identified, while 24.4% had AIDS. The most frequent clinical manifestations were headache (78.1%), fever (68.8%), nausea and vomiting (65.6%), confusion (50%) and meningeal signs (37.5%). Meningitis was the most frequent clinical presentation (87.8%). Amphotericin B was given to 93.5% of patients as an initial treatment. Positive microbiological identification was accomplished by India ink (94.7%), latex in cerebrospinal fluid (100%) and culture (89.5%). Out of 34 isolates studied, Cryptococcus neoformans var. grubii (VNI 85.3%, VNII 8.8%) was isolated in 94.1% of cases and Cryptococcus gattii (VGII) was isolated in 5.9% of cases. These data are complemented by a literature review, which overall suggests that cryptococcosis in children is an unusual event worldwide.

Proporción de leptospirosis y factores relacionados en pacientes con diagnóstico presuntivo de dengue, 2010-2012 / Leptospirosis percentage and related factors in patients having a presumptive diagnosis of dengue, 2010 -2012

Objetivo Identificar la presencia de leptospirosis y las variables sociodemográficas relacionadas, en pacientes con diagnóstico confirmado y descartado de dengue en el periodo 2010-2012, por medio de la técnica de microaglutinación (MAT). Materiales y Métodos Se realizó un estudio descriptivo retrospectivo de 238 sueros: 106 de pacientes fallecidos: 64 dengue negativo y 42 dengue positivo y 132 muestras de pacientes vivos dengue positivo: 29 confirmados por PCR y/o aislamiento viral y 103 con IgM positiva, a todos los sueros se les realizó la técnica de MAT para Leptospira, se revisaron las fichas epidemiológicas y se analizaron los datos. Resultados De los 42 pacientes fallecidos dengue positivo, 3 (7%) se encontraron positivos para Leptospira interrogans serogrupo Australis y Autumnalis; 2 mujeres, de 5 y 17 años y un hombre de 14 años.De los 64 pacientes fallecidos negativos para dengue, 7(11%) se encontraron positivos para L. interrogans de los serogrupos Pomona, Autumnalis, Canicola y Ballum; 5 hombres; edades entre 8 y 58 años; y 2 mujeres edades de 35 y 56 años. De los 103 pacientes vivos con IgM positiva para dengue, 3(2,9%) se encontraron positivos para Leptospira de los serogrupos Icterohaemorrhagiae, Cynopteri, Javanica, Proechimys y Autumnalis; 1 hombre y 2 mujeres. En los 29 pacientes vivos confirmados para dengue, no se encontraron positivos para Leptospira. Conclusiones Se debe sospechar de leptospirosis, no solo como único agente causal del síndrome febril, sino también de la coinfección que podría comprometer al paciente y estar relacionada con la mortalidad.(AU)

Objective Using the microscopic agglutination test (MAT) from 2010-2012 for identify ingleptospirosis-related and sociodemographic variables in patients havinga confirmed diagnosis of dengue and those for whom it had been discarded. Materials and Methods This was aretrospective study of 238 sera samples. 106 patients died, 64 of their samples were negative for dengue and 42 proved positive. 132 samples from live patients proved positive for dengue; 29 were confirmed by PCR and/orvirus isolation and 103 had positive IgM readings. MAT was used for all seraand diagnosing Leptospira, epidemiological records were reviewed and the data was analysed. Results 42 dengue positive patients died; 3 (7%) were positive for Leptospira interrogans sero group Australisautumnalis (two girls aged 5 and 17 years-old anda 14 year-old boy). Of the 64 deceased patients who proved negative for dengue, 7 (11%) were found positive for L.interrogans from sero groups Pomona, Autumnalis, Canicola and Ballum (5 malesaged 8to 58 years-old and 2 womenaged 35 and 56 years-old). Of the 103 living patients who proved positive for dengue IgM, 3 (2.9%) were positive for Leptospira icterohaemorrhagiae from the Cynopteri, Javanica Proechimys and Autumnalissero groups(1 maleand 2 females). None of the 29 living patients confirmedas having dengue were positive for Leptospira. Conclusions Leptospirosis should be suspected not onlyas the solecausative agent of febrile syndromebut also of co-infection which could compromisea patient and be related tomortality.(AU)

Cryptococcosis in Colombia: Results of the national surveillance program for the years 2006-2010 / Criptococosis en Colombia: resultados de la encuesta nacional, 2006-2010

Introduction: A survey on cryptococcosis is being conducted regularly in Colombia since 1997. We present hereby the results corresponding to patients diagnosed from 2006 to 2010. Objective: To analyze the data obtained during this period. Materials and methods: Retrospective analysis of the corresponding surveys. Results: A total of 526 surveys originating from 72% of the Colombian political divisions were received during the 5-year period. Most patients (76.6%) were males and 74.9% were 21-50 years old. The most prevalent risk factor was HIV infection (83.5%) with cryptococcosis defining AIDS in 23% of the cases. In the general population the estimated mean annual incidence rate for cryptococcosis was 2.4 x 106 inhabitants while in AIDS patients this rate rose to 3.3 x 103. In 474 surveys stating clinical features, most frequent complaints were headache 84.5%, fever 63.4%, nausea and vomiting 57.5%, mental alterations 46.3%, meningeal signs 33.0%, cough 26.4% and visual alterations 24.5%. Neurocryptococcosis was recorded in 81.8% of the cases. Laboratory diagnosis was based on direct examination, culture and latex in 29.3% cases. From 413 Cryptococcus isolates analyzed, 95.6% were identified as C. neoformans var. grubii, 1% C. neoformans var. neoformans, and 3.4% C. gattii. Treatment was reported for 71.6% of the cases with amphotericin B alone or in combination with fluconazole prescribed in 28%. Conclusions: Surveys done through passive surveillance continue to be sentinel markers for HIV infection and represent a systematic approach to the study of opportunistic problems regularly afflicting AIDS patients since cryptococcosis requires no compulsory notification in Colombia.

Introducción. Desde 1997 se viene realizando un programa nacional de vigilancia sobre la criptococosis en Colombia. Se presentan los resultados correspondientes a los pacientes diagnosticados entre el 2006 y el 2010. Objetivo. Analizar los datos obtenidos durante este periodo. Materiales y métodos. Análisis retrospectivo de las encuestas. Resultados. Durante los cinco años mencionados se recibieron 526 encuestas representativas del 72 % de la división política colombiana. La mayoría de pacientes (76,6 %) eran hombres y 74,9 % estaban entre los 21 y los 50 años. El factor de riesgo prevalente fue la infección por VIH (83,5 %), y la criptococosis definió el sida en 23 % de los casos. La incidencia anual promedio en la población general fue de 2,4 por un millón de habitantes mientras que, en pacientes con sida, aumentó a 3,3 por 1.000. En 474 encuestas se informaron manifestaciones clínicas; las más frecuentes fueron: cefalea (84,5 %), fiebre (63,4 %), náuseas y vómito (57,5 %), alteraciones mentales (46,3 %), signos meníngeos (33 %), tos (26,4 %) y alteraciones visuales (24,5 %). La neurocriptococosis se reportó en 81,8 % de los casos. El diagnóstico se hizo por examen directo, cultivo y antigenemia en 29,3 % de los casos. De 413 aislamientos recuperados, 95,6 % fueron C. neoformans var. grubii, 1 % C. neoformans var. neoformans, y 3,4 % C. gattii. En 71,6 % de los casos para el tratamiento se administró anfotericina B y en 28 % se combinó con fluconazol. Conclusiones. La vigilancia pasiva continúa siendo un marcador centinela para la infección por VIH, y constituye una aproximación sistemática al estudio de infecciones oportunistas en pacientes con sida, debido a que la criptococosis no es de notificación obligatoria en Colombia.

First environmental isolation of Cryptococcus gattii serotype B, from Cúcuta, Colombia / Primer aislamiento ambiental de Cryptococcus gattii de serotipo B, en Cúcuta, Colombia

Introduction. In Cúcuta, Cryptococcus gattii serotype B is commonly recovered from immunocompetent patients with cryptococcosis, but it has not been recovered from the environment in spite of its high incidence which is 77% out of reported cases. Objective. The aim of this work was to carry out an extensive environmental sampling in Cúcuta, in an attempt to isolate C. gattii serotype B and to expand our knowledge about the ecology and epidemiology of this important yeast. Materials and methods. Samples associated with 3,634 trees from 40 zones of Cúcuta were collected and processed with 28 samples collected near the houses of four patients with cryptococcosis caused by C. gattii serotype B. The serotype of the recovered isolates was done using multiplex PCR, molecular patterns were determined by RFLP of the URA5 gene and mating type was determined using the primers MfαU, MfαL, MFa2U and MFa2L. Results. In total, 4,389 samples were processed and one isolate of C. gattii serotype B (VGI/a), two isolates of C. gattii serotype C (VGIII/α) and three isolates of C. neoformans var. grubii, serotype A (VNI/α), were recovered. The density of the recovered isolates varied from 50 to 350 cfu/g of soil. Conclusions. This is the first report on the environmental isolation of C. gattii serotype B from Cúcuta. However, because of the low rate of recovery of isolates from soil only, the environmental niche of C. gattii has not been established and further environmental studies in Cúcuta are necessary, owing that this serotype is not only causing cryptococcosis but also has shown a higher virulence after the Vancouver outbreak.

Introducción. En Cúcuta, Cryptococcus gattii de serotipo B se recupera comúnmente de pacientes inmunocompetentes con criptococosis, pero no ha sido recuperado del ambiente a pesar su alta incidencia, que es de 77 % de los casos reportados. Objetivo. El objetivo de este trabajo fue realizar un extenso muestreo ambiental en Cúcuta, para aislar C. gattii de serotipo B y expandir nuestro conocimiento sobre la ecología y la epidemiología de esta importante levadura. Materiales y métodos. Se recolectaron y se procesaron muestras asociadas con 3.634 árboles de 40 zonas de Cúcuta y 28 muestras cercanas a las casas de cuatro pacientes con criptococosis causada por C. gattii de serotipo B. El serotipo de los aislamientos recuperados se estableció usando PCR múltiple, el patrón molecular se determinó por RFLP del gen URA5 y la pareja sexual se determinó usando los iniciadores MfαU, MfαL, MFa2U y MFa2L. Resultados. Se procesaron 4.389 muestras y se recuperó un aislamiento de C. gattii de serotipo B (VGI/a), dos aislamientos de C. gattii de serotipo C (VGIII/α) y tres aislamientos de C. neoformans var. grubii de serotipo A (VNI/α). La densidad de los aislamientos recuperados varió entre 50 y 350 UFC/g de suelo. Conclusiones. Éste es el primer reporte de la recuperación ambiental de C. gattii de serotipo B en Cúcuta. Sin embargo, por la baja tasa de recuperación de aislamientos únicamente en suelo, el nicho ambiental de C. gattii no se pudo establecer, por lo que es necesario realizar posteriores estudios ambientales en Cúcuta, debido a que este serotipo, no sólo está causando criptococosis, sino también muestra una gran virulencia después del brote ocurrido en Vancouver.

Aislamiento de Cryptococcus gattii serotipo B a partir de detritos de Eucalyptus spp. en Colombia / Isolation of Cryptococcus gattii serotype B from detritus of Eucalyptus trees in Colombia

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 por ciento ). 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