title: Occurrence of fungi and cytotoxicity of the species: Aspergillus ochraceus, Aspergillus niger and Aspergillus flavus isolated from the air of hospital wards.
abstract: OBJECTIVE
  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.
  
  
  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 theAspergillus genus. Sixty-one strains of species other thanA. fumigatuswere selected for the research purposes, namely: 28 strains ofA. ochraceus, 22 strains ofA. nigerand 11 strains ofA. flavusspecies. 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 (IC50) for values ranging from 31.251 cm2/ml to 7.813 cm2/ml, medium cytotoxic effect (++) for values ranging from 3.906 cm2/ml to 0.977 cm2/ml and the high one (+++) for values ranging from 0.488 cm2/ml to 0.061 cm2/ml. The absence of cytotoxicity was determined when the IC50values was at ≥ 50.
  
  
  RESULTS
  For 48 samples the analyzed fungi displayed the cytotoxic effect withA. ochraceusin 26 out of 28 cases, with 11 strains displaying the high cytotoxic effect. The lowest cytotoxicity was displayed by fungi ofA. niger in 13 out of 22 cases, and the major fungi ofA. flavusspecies 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.
authors.affiliation: 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.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Gniadek
authors.affiliation: Jagiellonian University Medical College, Kraków, Poland (Faculty of Health Sciences, Chair of Microbiology, Department of Mycology). p.krzysciak@gmail.com.
authors.forename: Paweł
authors.initials: P
authors.lastname: Krzyściak
authors.affiliation: Kazimierz Wielki University, Bydgoszcz, Poland (Faculty of Natural Sciences, Institute of Experimental Biology, Department of Physiology and Toxicology). twarmag@ukw.edu.pl.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Twarużek
authors.affiliation: Jagiellonian University Medical College, Kraków, Poland (Faculty of Health Sciences, Chair of Microbiology, Department of Mycology). mbmacura@cyf-kr.edu.pl.
authors.forename: Anna B
authors.initials: AB
authors.lastname: Macura
mesh_terms: D000391:Air Microbiology; D001231:Aspergillus flavus / Q000472:pathogenicity*; D001234:Aspergillus niger / Q000472:pathogenicity*; D001235:Aspergillus ochraceus / Q000472:pathogenicity*; D006761:Hospitals; D009183:Mycotoxins / Q000633:toxicity; D011044:Poland
chemical_list: D009183:Mycotoxins
keywords: Aspergillus; MTT assay; air sampling; airborne fungi; cytotoxicity; hospital environment