Capacity ofHistoplasma capsulatumto Survive the Composting Process

Luisa Fernanda Gómez Londoño,Carlos Alberto Peláez Jaramillo,María Del Pilar Jiménez Alzate,Juan Guillermo Mcewen Ochoa,Myrtha Arango Arteaga,Jose Miguel Acevedo Ruiz,Alejandra Zuluaga Rodriguez,María Lucia Taylor,Laura Carolina Pérez León

doi:10.1155/2019/5038153

Luisa Fernanda Gómez Londoño, Carlos Alberto Peláez Jaramillo + Show 7 more

Open Access

https://doi.org/10.1155/2019/5038153

Copy DOI

Abstract

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.

Highlights

Histoplasma capsulatum (H. capsulatum) is a thermally dimorphic fungus and the causal agent of histoplasmosis
As poultry manure favors the growth of H. capsulatum due to its high content of phosphorus and nitrogen and because it is the raw material for the production of many organic fertilizers, we propose that these fertilizers might represent an important source of H. capsulatum infection
Histoplasma capsulatum isolate 13180 was obtained from a bronchoalveolar lavage sample provided by a patient who attended to the Medical and Experimental Mycology Unit, at the Corporacion para Investigaciones Biologicas (CIB). e isolate was maintained at room temperature in the mycelial phase by passaging every three months in tubes containing fresh Mycosel agar

Summary

Introduction

Histoplasma capsulatum (H. capsulatum) is a thermally dimorphic fungus and the causal agent of histoplasmosis. H. capsulatum inhabits porous soils with high concentrations of phosphorus and nitrogen, with a large organic matter content and an acidic pH. It is favored by temperatures between 22 and 29°C, annual precipitation around 1000 to 1200 mm and a relative humidity of between 67 and 87%. Histoplasmosis is often diagnosed in urban and rural areas and may affect farmers, gardeners, housekeepers, builders, explorers, speleologists, and archaeologists People involved in these occupations are more predisposed to becoming infected with H. capsulatum; histoplasmosis has been classified as an occupational and recreational disease [10,11,12,13]

Methods

Results

Conclusion