The thermally dimorphic fungus Histoplasma capsulatum is the causative agent of histoplasmosis, one of the most prevalent endemic mycosis in the Americas. In tropical regions, agro-ecosystems require organic matter replacement, therefore, the use of organic fertilizers has increased disregarding the fact that certain number of such fertilizers might be contaminated with the fungus, and with their handling resulting in human cases and even outbreaks of histoplasmosis. Additionally, in Colombia, chicken manure is the most common raw material used in the production of organic fertilizers. In this work, we reported the isolation of this fungus from chicken manure, and genetically compared with 42 clinical isolates. The genetically compared environmental isolates grouped together with the clinical ones. Our result suggests that chicken manure may be one of H. capsulatum infection sources. Also, the phylogenetic analyses done with other H. capsulatum isolates indicate that the Colombian isolates are widely distributed in the relational tree thus reveling towards the great genetic diversity among the H. capsulatum Colombian isolates.

Histoplasma capsulatum (H. capsulatum)is a thermal-dimorphic fungus, the causal agent of histoplasmosis. Its presence in the environment is related with chicken manure due to their high nitrogen and phosphorus content. In Colombia, chicken manure is the most used raw material in the composting process; however, there is no information about the capacity ofH. capsulatumto survive and remain viable in a composted organic fertilizer. To address this question, this study shows three assays based on microbiological culture and the Hc100 nested PCR. First, a composting reactor system was designed to transform organic material under laboratory conditions, and the raw material was inoculated with the fungus. From these reactors, the fungus was not isolated, but its DNA was detected. In the second assay, samples from factories where the DNA of the fungus was previously detected by PCR were analyzed. In the raw material samples, 3 colonies ofH. capsulatumwere isolated and its DNA was detected. However, after the composting process, neither the fungus was recovered by culture nor DNA was detected. In the third assay, sterilized and nonsterilized organic composted samples were inoculated withH. capsulatumand then evaluated monthly during a year. In both types of samples, the fungus DNA was detected by Hc100 nested PCR during the whole year, but the fungus only grew from sterile samples during the first two months evaluated. In general, the results of the assays showed thatH. capsulatumis not able to survive a well-done composting process.

Coccidioides is a soil-borne fungal pathogen and causative agent of a human respiratory disease (coccidioidomycosis) endemic to semi-desert regions of southwestern United States, Mexico, Central and South America. Aerosolized arthroconidia inhaled by the mammalian host first undergo conversion to large parasitic cells (spherules, 80–100 μm diameter) followed by endosporulation, a process by which the contents of spherules give rise to multiple endospores. The latter are released upon rupture of the maternal spherules and establish new foci of lung infection. A novel feature of spherule maturation prior to endosporulation is the secretion of a lipid-rich, membranous cell surface layer shed in vivo during growth of the parasitic cells and secretion into liquid culture medium during in vitro growth. Chemical analysis of the culture derived spherule outer wall (SOW) fraction showed that it is composed largely of phospholipids and is enriched with saturated fatty acids, including myristic, palmitic, elaidic, oleic, and stearic acid. NMR revealed the presence of monosaccharide- and disaccharide-linked acylglycerols and sphingolipids. The major sphingolipid components are sphingosine and ceramide. Primary neutrophils derived from healthy C57BL/6 and DBA/2 mice incubated with SOW lipids revealed a significant reduction in fungicidal activity against viable Coccidioides arthroconidia compared to incubation of neutrophils with arthroconidia alone. Host cell exposure to SOW lipids had no effect on neutrophil viability. Furthermore, C57BL/6 mice that were challenged subcutaneously with Coccidioides arthroconidia in the presence of the isolated SOW fraction developed disseminated disease, while control mice challenged with arthroconidia alone by the same route showed no dissemination of infection. We hypothesize that SOW lipids contribute to suppression of inflammatory response to Coccidioides infection. Studies are underway to characterize the immunosuppressive mechanism(s) of SOW lipids.

: Histoplasmosis, one of the most frequent endemic mycoses in the Americas, is caused by the inhalation of airborne conidia of Histoplasma capsulatum. Better understanding of the distribution of this fungus in the environment is important for the development of appropriate public health measures to prevent human infections. Previously, we used Hc100 nested polymerase chain reaction (PCR) to identify H. capsulatum DNA in 10% of environmental samples in Colombia. Here, we validate a 100-kDa real-time PCR assay for the detection of this fungus in the environment. Using this method, we identified H. capsulatum DNA in 80% of samples of raw organic materials, such as chicken manure, soil from caves, and bird and bat guano, as well as in 62% of samples of organic fertilizer that underwent the composting process. We demonstrated that 100-KDa real-time PCR is a useful tool for environmental surveillance that can be used to identify the potential reservoirs of H. capsulatum and to prevent outbreaks, especially in people with the higher risk of exposure, such as spelunkers, farmers, poultry manure collectors, and anyone who handle organic fertilizers or bat and bird excreta.

La paracoccidioidomicosis es una micosis sistémica endémica en Latinoamérica. La presentación más frecuente compromete crónicamente los pulmones, la piel y las mucosas. Al inicio, este paciente presentó, por varios años, una lesión única en la mucosa oral que, en ausencia de otros síntomas, se relacionó con una neoplasia maligna, específicamente con un carcinoma escamocelular.La diferenciación entre los dos diagnósticos se hace mediante un examen directo, un estudio histopatológico y cultivos iniciales y subsecuentes. Sin embargo, tales estudios no fueron concluyentes. Después de varias consultas y pruebas, con los resultados del examen directo, la inmunodifusión y la PCR en tiempo real se confirmó el diagnóstico de paracoccidioidomicosis crónica multifocal.Este caso alerta sobre la ausencia de sospecha clínica de micosis endémicas, dada la presencia de lesiones mucocutáneas que pueden ser producidas por hongos como Paracoccidioides spp, y la importancia de considerarlas entre los diagnósticos diferenciales.

Introducción. Las dermatofitosis son infecciones fúngicas superficiales de epitelios queratinizados. La tinea capitis es una de ellas y afecta a poblaciones escolares vulnerables. Carpinelo es un barrio del área periférica de Medellín con precarias condiciones socioeconómicas. Ante la sospecha de un brote de dermatofitosis, losafectados fueron evaluados.Objetivo. Evaluar clínica y microbiológicamente pacientes del barrio Carpinelo con sospecha de micosis cutáneas para determinar la presencia de un brote por dermatofitos.Materiales y métodos. Se llevó a cabo un estudio descriptivo, de corte longitudinal, con muestreo a conveniencia. Se hizo una búsqueda activa de casos en el Jardín Educativo Buen Comienzo de Carpinelo en niños de la institución y sus familiares. Se evaluaron clínicamente y se tomaron muestras de escamas y cabellos para exámenes directos y cultivos microbiológicos. Se analizó el perfil demográfico, clínico y micológico, con el programa estadístico SPSS™, versión 25.Resultados. Se estudiaron 57 pacientes, 47 eran menores de edad con una media de edad de seis años; se observó una proporción de hombres y mujeres de 2:1. Los pacientes con resultados positivos se diagnosticaron con tinea capitis (78,95 %), tinea faciei (15,79 %) y tinea corporis (10,52 %). El 75,43 % de los pacientes recibió tratamiento previo y de estos el 69,73 % fue con esteroides. El examen directo fue positivo en el 53,84 % y los cultivos en el 46,5 % de los casos. Los agentes aislados fueron: Microsporum canis (77,77 %), Trichophyton spp. (11,11 %), Trichophyton rubrum (5,55 %) y Malassezia spp. (5,55 %).Conclusión. Tinea capitis fue la presentación clínica más común y M. canis el dermatofito más frecuentemente aislado. Llamó la atención el uso de esteroides como primera y única opción del tratamiento empírico‚ lo cual resalta la importancia del diagnóstico microbiológico para proporcionar la terapia apropiada.