Effect of the oscillating magnetic field on airborne fungal.

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.

Influencia del campo magnético sobre la distribución de los hongos en el aire de un local cerrado / Influence of magnetic field on fungi distribution in the air of a closed local

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.

Influencia del campo magnético sobre el crecimiento de microorganismos patógenos ambientales aislados en el Archivo Nacional de la República de Cuba / Influence of magnetic field on the growth of pathogen microorganisms isolated from the indoor environment at the Archivo Nacional de la República de Cuba

Introducción. En el Archivo Nacional de la República de Cuba, existe contaminación electromagnética y la influencia del campo magnético oscilante de frecuencia extremadamente baja podría cuantificarse con microorganismos patógenos aislados de su ambiente interior. Objetivo. Cuantificar la influencia de este tipo de campo magnético sobre el crecimiento de microorganismos patógenos aislados del ambiente en el Archivo Nacional de la República de Cuba. Materiales y métodos. Se emplearon cinco microorganismos: Streptococcus sp. (1), Listeria sp. (2) y Candida guillermondii (3), aislados en el Archivo, así como Escherichia coli ATCC 25922 (4) y Saccharomyces cerevisiae (5), como referencia. Se les aplicó un campo magnético oscilante de frecuencia extremadamente baja de 60 Hz/220 V de 3 mT durante dos horas, en tres tubos de cultivo con agua destilada y con caldo nutriente. Después se inocularon 0,1 ml en placas de Petri con los medios de cultivo agar CromoCen SC (1 y 2), agar de dextrosa y papa (3), agar CromoCen CC 4227 (4) y agar con extracto de malta (5). Las colonias se contaron (log UFC/ml) mediante el procesamiento digital de las imágenes de las placas de Petri empleando el programa MatLab ® . Resultados. Se observó una estimulación significativa (p=0,05) de la cantidad de colonias tratadas con respecto a los controles, siendo mayor en el caldo nutriente que en el agua destilada y más en las bacterias (caldo nutriente-colonias tratadas: 9,43 a 10,62 UFC/ml) que en las levaduras (caldo nutriente-colonias tratadas: 8,31 a 8,79 UFC/ml). La estimulación se produjo en orden decreciente así: Listeria sp., E. coli ATCC 25922, Streptococcus sp., C. guillermondii y S. cerevisiae . Conclusión. Se concluyó que el campo magnético aplicado tuvo un efecto estimulante sobre los microorganismos estudiados, lo cual potencia el riesgo para la salud del personal y los visitantes del Archivo Nacional de la República de Cuba.

Introduction: Electromagnetic pollution has been detected at the Archivo Nacional de la República de Cuba and the influence of extremely low frequency magnetic fields could be quantified with pathogenic microorganisms isolated from the indoor environment. Objective: To quantify the influence of an extremely low frequency magnetic field on the growth of pathogenic microorganisms isolated from the environment at the Archivo Nacional. Materials and methods: We used five microorganisms isolated at the Archivo Nacional: Streptococcus sp. (1), Listeria sp. (2) and Candida guillermondii (3), and Escherichia coli ATCC 25922 (4) and Saccharomyces cerevisiae (5) as references. We applied this magnetic field of extremely low frequency, 60 Hz/220 V (3 mT), for two hours to these microorganisms on three culture tubes with distilled water and nutrient broth. Then we inoculated 0.1 mL in the following solid culture mediums on Petri dishes: CromoCen SC Agar (1 and 2), Potato Dextrose Agar (3), CromoCen DC 4227 (4) and Malt Extract Agar (5). The colonies were counted (log CFU/mL) by digital processing of the images of Petri dishes using the MatLab ® tool. Results: We observed a statistically significant stimulation (p=0.05) in the quantity of treated colonies as compared to controls, which was higher in nutrient broth than in distilled water, and in bacteria (nutrient broth and treated colonies: 9.43 to 10.62 CFU/mL) as compared with yeasts (nutrient broth-treated colonies: 8.31 to 8.79 CFU/mL). In decreasing order, stimulation was as follows: Listeria sp., E. coli ATCC 25922, Streptococcus sp., C. guillermondii and S. cerevisiae . Conclusion: We concluded that the magnetic field applied had a stimulating effect on the microorganisms under study, which increases the risk to the health of staff and visitors at the Archivo Nacional .

[Influence of magnetic field on the growth of pathogen microorganisms isolated from the indoor environment at the Archivo Nacional de la República de Cuba]. / Influencia del campo magnético sobre el crecimiento de microorganismos patógenos ambientales aislados en el Archivo Nacional de la República de Cuba.

INTRODUCTION: Electromagnetic pollution has been detected at the Archivo Nacional de la República de Cuba and the influence of extremely low frequency magnetic fields could be quantified with pathogenic microorganisms isolated from the indoor environment. OBJECTIVE: To quantify the influence of an extremely low frequency magnetic field on the growth of pathogenic microorganisms isolated from the environment at the Archivo Nacional. MATERIALS AND METHODS: We used five microorganisms isolated at the Archivo Nacional: Streptococcus sp. (1), Listeria sp. (2) and Candida guillermondii (3), and Escherichia coli ATCC 25922 (4) and Saccharomyces cerevisiae (5) as references. We applied this magnetic field of extremely low frequency, 60 Hz/220 V (3 mT), for two hours to these microorganisms on three culture tubes with distilled water and nutrient broth. Then we inoculated 0.1 mL in the following solid culture mediums on Petri dishes: CromoCen SC Agar (1 and 2), Potato Dextrose Agar (3), CromoCen DC 4227 (4) and Malt Extract Agar (5). The colonies were counted (log CFU/mL) by digital processing of the images of Petri dishes using the MatLab ® tool. RESULTS: We observed a statistically significant stimulation (p=0.05) in the quantity of treated colonies as compared to controls, which was higher in nutrient broth than in distilled water, and in bacteria (nutrient broth and treated colonies: 9.43 to 10.62 CFU/mL) as compared with yeasts (nutrient broth-treated colonies: 8.31 to 8.79 CFU/mL). In decreasing order, stimulation was as follows: Listeria sp., E. coli ATCC 25922, Streptococcus sp., C. guillermondii and S. cerevisiae . CONCLUSION: We concluded that the magnetic field applied had a stimulating effect on the microorganisms under study, which increases the risk to the health of staff and visitors at the Archivo Nacional .