Agnieszka Gniadek1, Paweł Krzyściak2, Magdalena Twarużek3, Anna B Macura4. 1. Jagiellonian University Medical College, Kraków, Poland (Faculty of Health Sciences, Institute of Nursing and Midwifery, Department of Nursing Management and Epidemiology Nursing). agnieszka.gniadek@uj.edu.pl. 2. Jagiellonian University Medical College, Kraków, Poland (Faculty of Health Sciences, Chair of Microbiology, Department of Mycology). p.krzysciak@gmail.com. 3. Kazimierz Wielki University, Bydgoszcz, Poland (Faculty of Natural Sciences, Institute of Experimental Biology, Department of Physiology and Toxicology). twarmag@ukw.edu.pl. 4. Jagiellonian University Medical College, Kraków, Poland (Faculty of Health Sciences, Chair of Microbiology, Department of Mycology). mbmacura@cyf-kr.edu.pl.
Abstract
OBJECTIVES: The basic care requirement for patients with weakened immune systems is to create the environment where the risk of mycosis is reduced to a minimum. MATERIAL AND METHODS: Between 2007 and 2013 air samples were collected from various wards of a number of hospitals in Kraków, Poland, by means of the collision method using MAS-100 Iso MH Microbial Air Sampler (Merck Millipore, Germany). The air mycobiota contained several species of fungi, and almost 1/3 of it was made up of the species of the <i>Aspergillus genus</i>. Sixty-one strains of species other than <i>A. fumigatus</i> were selected for the research purposes, namely: 28 strains of <i>A. ochraceus</i>, 22 strains of <i>A. niger</i> and 11 strains of <i>A. flavus</i> species. Selected fungi underwent a cytotoxicity evaluation with the application of the MTT colorimetric assay (3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide). The assay assesses cell viability by means of reducing the yellow tetrazolium salt to insoluble formazan. A semi-quantitative scale for cytotoxicity grading was adopted: low cytotoxic effect (+) with half maximal inhibitory concentration (IC<sub>50</sub>) for values ranging from 31.251 cm<sup>2</sup>/ml to 7.813 cm<sup>2</sup>/ml, medium cytotoxic effect (++) for values ranging from 3.906 cm<sup>2</sup>/ml to 0.977 cm<sup>2</sup>/ml and the high one (+++) for values ranging from 0.488 cm<sup>2</sup>/ml to 0.061 cm<sup>2</sup>/ml. The absence of cytotoxicity was determined when the IC<sub>50</sub> values was at ≥ 50. RESULTS: For 48 samples the analyzed fungi displayed the cytotoxic effect with <i>A. ochraceus</i> in 26 out of 28 cases, with 11 strains displaying the high cytotoxic effect. The lowest cytotoxicity was displayed by fungi of <i>A. nige</i>r in 13 out of 22 cases, and the major fungi of <i>A. flavus</i> species were toxic (9 out of 11 cases). CONCLUSIONS: A half of the fungi displayed the low cytotoxic effect. On the basis of the comparison of average cytotoxicity levels it was determined that there were significant differences in the levels of cytotoxicity of the analyzed fungi. However, such statement may not provide grounds for a definite conclusion about the compared species of fungi that display a more cytotoxic effect than others. Int J Occup Med Environ Health 2017;30(2):231-239. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.
OBJECTIVES: The basic care requirement for patients with weakened immune systems is to create the environment where the risk of mycosis is reduced to a minimum. MATERIAL AND METHODS: Between 2007 and 2013 air samples were collected from various wards of a number of hospitals in Kraków, Poland, by means of the collision method using MAS-100 Iso MH Microbial Air Sampler (Merck Millipore, Germany). The air mycobiota contained several species of fungi, and almost 1/3 of it was made up of the species of the <i>Aspergillus genus</i>. Sixty-one strains of species other than <i>A. fumigatus</i> were selected for the research purposes, namely: 28 strains of <i>A. ochraceus</i>, 22 strains of <i>A. niger</i> and 11 strains of <i>A. flavus</i> species. Selected fungi underwent a cytotoxicity evaluation with the application of the MTT colorimetric assay (3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide). The assay assesses cell viability by means of reducing the yellow tetrazolium salt to insoluble formazan. A semi-quantitative scale for cytotoxicity grading was adopted: low cytotoxic effect (+) with half maximal inhibitory concentration (IC<sub>50</sub>) for values ranging from 31.251 cm<sup>2</sup>/ml to 7.813 cm<sup>2</sup>/ml, medium cytotoxic effect (++) for values ranging from 3.906 cm<sup>2</sup>/ml to 0.977 cm<sup>2</sup>/ml and the high one (+++) for values ranging from 0.488 cm<sup>2</sup>/ml to 0.061 cm<sup>2</sup>/ml. The absence of cytotoxicity was determined when the IC<sub>50</sub> values was at ≥ 50. RESULTS: For 48 samples the analyzed fungi displayed the cytotoxic effect with <i>A. ochraceus</i> in 26 out of 28 cases, with 11 strains displaying the high cytotoxic effect. The lowest cytotoxicity was displayed by fungi of <i>A. nige</i>r in 13 out of 22 cases, and the major fungi of <i>A. flavus</i> species were toxic (9 out of 11 cases). CONCLUSIONS: A half of the fungi displayed the low cytotoxic effect. On the basis of the comparison of average cytotoxicity levels it was determined that there were significant differences in the levels of cytotoxicity of the analyzed fungi. However, such statement may not provide grounds for a definite conclusion about the compared species of fungi that display a more cytotoxic effect than others. Int J Occup Med Environ Health 2017;30(2):231-239. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.