Jose Miguel Acevedo Ruiz

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.

The thermally dimorphic fungus Histoplasma capsulatum is the causative agent of histoplasmosis, which is the most prevalent endemic mycosis in America. The replacement of organic matter in agro-ecosystems is necessary in the tropics, and the use of organic fertilizers has increased. Cases and outbreaks due to the presence of the fungus in these components have been reported. In Colombia, chicken manure is the most common raw material in the organic fertilizers production. In this work, we reached the isolation of the fungus from a chicken manure. Then, we were able to compare genetically 3 environmental isolates with 42 Colombian human clinical isolates. The genetic comparison showed the environmental isolates grouping together with the clinical isolates. This result suggests chicken manure as one of the infection source with H. capsulatum . Also, the phylogenetic analysis using another H. capsulatum isolates from databases showed that the Colombian isolates widely distributed in the relation tree. This result pointed out the great genetic diversity among H. capsulatum Colombian population.

Objective This study was aimed at evaluating pertinent physicochemical and microbiological (bacteria and parasites) parameters regarding the biosolids produced by the San Fernando wastewater treatment plant (WWTP) in Itagui, Antioquia, Colombia. Methods Twelve samples were collected and evaluated every month from January to December during 2010. The chemical, physical and microbiological tests followed the protocol described in Colombian technical guideline 5167. The protocol described in Mexican official Norm 004 (with some modifications) was used for identifying helminth ova and assessing their viability. Results All samples proved positive for Ascarislumbricoides, viable ova count ranging from 4 to 22 eggs/2gTS. Both Salmonella and Enterobacteriawere detected in all samples evaluated, the latter having 3,000 colony forming unit (CFU)/g minimum concentration. Biosolid sample values met the heavy metal concentration requirement established by national guidelines. There was no statistical association between rainfall and the pathogen's presence in the biosolids. Conclusion Our results suggested that the biosolids being produced by the San Fernando wastewater treatment plant (WWTP) could be used as organic fertilizer; however they should be treated/sanitized to meet the stipulations in Colombian technical guideline 5167.