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Fungi are ubiquitous and metabolically versatile. Their dispersion has important scientific, environmental, health, and economic implications. They can be dispersed through the air by the aerosolization of near surfaces or transported from distant sources. Here, we tested the contribution of local (scale of meters) versus regional (kilometers) sources by analyzing an airborne fungal community by ITS sequencing around a copper mine in the North of Chile. The mine was the regional source, whereas the soil and vegetal detritus were the local sources at each point. The airborne community was highly homogeneous at ca. 2000 km2, impeding the detection of regional or local contributions. Ascomycota was the dominant phylum in the three communities. Soil and vegetal detritus communities had lower alpha diversity, but some taxa had abundance patterns related to the distance from the mine and altitude. On the contrary, the air was compositionally even and unrelated to environmental or spatial factors, except for altitude. The presence of plant pathogens in the air suggests that other distant sources contribute to this region's airborne fungal community and reinforces the complexity of tracking the sources of air microbial communities in a real world where several natural and human activities coexist.

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This study shows that some species of fungi are affected by the magnetic field, which should be taken into account in studies of airborne fungal and air quality. The aim of this paper was to evaluate the effect of the oscillating magnetic field (OMF) on the behavior of colonies of three fungi genus growth in different culture mediums. The stains were: Aspergillus niger, Cladosporium cladosporioides and Penicillium citrinum and were inoculated in 90 mm Petri dishes with: Malt Extract Agar (MEA), Sabouraud Dextrose Agar (SDA) and Czapek-Dox Agar (CDA). Was applied them OMF of 60 Hz/220 V between 1 and 5 mT during 2 h and then they were incubated 7 days to 28 °C. Colonies size (mm) every day was measured. Stimulation in the colonies size of all experimental conditions was showed; the greatest size of A. niger in MEA was notorious. It was demonstrated by statist analyze that only colonies size with 1 mT was significance respect to the control. The effect of OMF on the cellular metabolism was evidenced, as well as: less exudation and major pigmentation of P. citrinum in MEA; variation of pigmentation of A. niger and C. cladosporioides in CDA and increase of conidiogenesis of A. niger in SDA. Was concluded that the applied OMF had a major influence on size colony and mycelia pigmentation of A. niger that C. cladosporioides and P. citrinum, independently of the nutritional state according to the culture medium employed in this study.

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INTRODUCTION: Although airborne fungal diversity in tropical countries is known to be considerable, aerobiological research to-date has identified only a part of the fungal mycobiota that may have an impact both on human health and on crops. Previous studies in Havana city identified only 30 genera and 5 spore types; therefore,new research is required in these latitudes. This study sought to investigate airborne spore levels in Havana, with a view to learning more about local fungal diversity and assessing its influence in quantitative terms. MATERIAL AND METHODS: A Hirst type volumetric sampler was located on the rooftop of a building 35 meters above ground level, in a busy area of the city. Sampling was carried out continuously (operating 24hours/day), at 10 L per minute during the year 2015. The fungal spores were collected on a Melinex tape coated with a 2% silicone solution. The results were expressed as spores per cubic meter (spores/m3) of air when to referring to daily values, and spores count if referring to annual value. RESULTS: Fourteen new genera were identified in the course of volumetric sampling: six produce ascospores and eight conidia. Morphobiometric characteristics were noted for all genera, and airborne concentrations were calculated. These genera accounted for 56.4% of relative fungal frequency over the study year. CONCLUSIONS: Many airbone fungi are primary causes of both respiratory disease and crop damage. These new findings constitute a major contribution to Cuba's aerobiological database.

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Los campos eléctricos y magnéticos pueden atraer microorganismos, por lo tanto el objetivo de este estudio fue analizar la influencia del campo magnético sobre la distribución de los hongos en el aire de un local cerrado. Se colocaron placas de Petri con agar Extracto de Malta en un local cerrado aplicándose un campo magnético de 10 mT generado por una bobina de 60 Hz/220 V. Se realizó un diseño multifactorial D-óptimo de tres factores (tiempo de exposición al aire, distancia al centro de la bobina y tiempo de tratamiento con campo magnético) y se determinó el recuento de hongos filamentosos en unidades formadoras de colonias por metro cúbico de aire, según el método de sedimentación propuesto por Omeliansky. Se obtuvo un modelo cuadrático en los rangos evaluados, que indicó que el tratamiento aplicado tuvo influencia significativa sobre la distribución de las esporas debido al aumento del recuento de los hongos, cuyo crecimiento resultó estimulado con respecto a los controles. El mayor efecto estimulante se observó a 1 m de distancia de la bobina (0,4 mT) y a 2 h de exposición, alcanzándose concentraciones fúngicas que pudieran ser peligrosas para la salud humana según la Organización Mundial de la Salud.

Electric and magnetic fields can attract microorganisms; based on those premises the aim of this study was to analyze the influence of a magnetic field on the fungi distribution in the air of a closed environment. Uncovered Petri dishes with Malt Extract Agar were placed in a closed area where a magnetic field of 10 mT generated by a coil of 60 Hz / 220 V was applied. A multifactorial D-optimum design considering three elements (air exposure time, distance to the center of the coil and time of magnetic field application) to determine the amount of filamentous fungi, expressed as the number of colony forming units by cubic meter of air, according to the sedimentation method proposed by Omeliansky. A quadratic model of the evaluated ranges was obtained, which indicated that the treatment applied showed significant influence on fungal spore distribution demonstrated by the increased fungal count which growth was stimulated by the treatment applied when compared to the controls. The largest stimulant effect was observed at 1 m of distance from the coil (0.4 mT) and after 2 h of exposure, conditions that permitted the growth of fungal concentrations that could be dangerous for human health according to the World Health Organization.

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The fungal spore concentration (FSC) in the air poses a risk for human health. This work studied the FSC in university libraries and how it is affected by environmental factors. A total of 347 samples were obtained using a Microbio MB2(®) Aerosol Sampler. The wind speed (WS), cross wind (CW), temperature (T), relative humidity (HR), barometric pressure (BP) and dew point (DP) were recorded using a Kestrel(®) 4500 weather station. The median indoor/outdoor FSC was 360/1230 CFU m(-3). FSC correlated inversely with BP, HR and DP; and positively with WS and CW; whereas T showed negative or positive correlation with FSC, depending on the region or sampling time. Eleven fungal genera were found and the dominant isolates were identified as Aspergillus niger, Aspergillus tamarii and Aspergillus oryzae. All fungi identified are known to be allergenic. It was concluded that environmental variables can influence the air FSC in different ways.

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Worldwide aging of the human population has promoted an increase in the incidence of neoplasia, including hematological cancers, which render patients particularly vulnerable to invasive fungal infections. For this reason, air filtration in hemato-oncology units has been recommended. However, scarce literature has assessed the impact of microbiological air quality on the occurrence of fungal infections in this population. We performed an integrative review of studies in the MEDLINE database that were published between January 1980 and October 2012, using the following combinations of keywords: air × quality × HEPA, air × quality × hematology, and airborne fungal infections. The search yielded only 13 articles, suggesting that high-efficiency filtering of the ambient air in hemato-oncology units can prevent the incidence of invasive fungal infections. However, no randomized clinical trial was found to confirm this suggestion. Currently, there is no consensus about the maximum allowable count of fungi in the air, which complicates filtration monitoring, including filter maintenance and replacement, and needs to be addressed in future studies.

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