Occurrence of fungi and cytotoxicity of the species: Aspergillus ochraceus, Aspergillus niger and Aspergillus flavus isolated from the air of hospital wards

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 Aspergillus genus. Sixty-one strains of species other than A. fumigatus were selected for the research purposes, namely: 28 strains of A. ochraceus, 22 strains of A. niger and 11 strains of A. flavus species. Selected fungi underwent a cytotoxicity evaluation with the application of the MTT colorimetric assay (3-(4,5-dimethylthiazol-2-yl)-2,5-di phenyltetrazolium 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 50 ) for values ranging from 31.251 cm 2 /ml to 7.813 cm 2 /ml, medium cytotoxic effect (++) for values ranging from 3.906 cm 2 /ml to 0.977 cm 2 /ml and the high one (+++) for values ranging from 0.488 cm 2 /ml to 0.061 cm 2 /ml. The absence of cytotoxicity was determined when the IC 50 values was at ≥ 50. Results: For 48 samples the analyzed fungi displayed the cytotoxic effect with A. ochraceus in 26 out of 28 cases, with 11 strains displaying the high cytotoxic effect. The lowest cytotoxicity was displayed by fungi of A. niger in 13 out of 22 cases, and the major fungi of A. flavus 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

Fungal contamination of ward furnishings and medical equipment used in the treatment and nursing of newborns

“…Also in the authors' own study, moulds belonging to Aspergillus genus made up a significant percentage of the identified fungi, including A. fumigatus, which was observed in over a half of the isolates of this type. The fungi belonging to Aspergillus genus might present a significant threat to patients' health, especially those with impaired immunity, and particularly newborns [28,29,30]. They may also pose a threat to the staff working in these rooms because they are included in the group of 2 biological factors which may have negative effects on people exposed to them for prolonged periods [31].…”

Fungi in the indoor air of critical hospital areas: a review

“…Open Petri dishes were exposed to air for between 10 and 30 min at a height of 80 to 150 cm from the floor. However, most authors employed air vacuum devices such as Anderson single-step model (10-710), MAS 100 Iso MH Microbial Air Sampler (Merck Millipore, Germany), SAS SUPER 100 (Merck), and LWC (Kangjie Instrument Research Institute, Liaoyang, China) at a variable flow rate (28.3-100 L/min) to obtain the suspended particle concentration (Martins-Diniz et al, 2005;Krajewska-Kułak et al, 2007;Chuaybamroong et al, 2008;Quadros et al, 2009;Ortiz et al, 2009;Qudiesat et al, 2009;Gniadek et al, 2010;Kim et al, 2010;Boff et al, 2013;Macedo et al, 2013;Park et al, 2013;Hoseinzadeh et al, 2013;El-Sharkawy & Noweir, 2014;Maldonado-Vega et al, 2014;Yu et al, 2015;Gniadek et al, 2017;Abbasi & Samaei, 2019). In some studies, material from inanimate surfaces (keyboards, phones, stethoscope, beds, door handles, walls, and equipment) was also collected by means of swabs or imprints (Martins-Diniz et al, 2005;Krajewska-Kułak et al, 2007;Melo et al, 2009;Qudiesat et al, 2009;Sales et al, 2011;Aboul-Nasr et al, 2014).…”

Bioburden Assessment by Passive Methods on a Clinical Pathology Service in One Central Hospital from Lisbon: What Can it Tell Us Regarding Patients and Staff Exposure?

“…Regarding fungi, Aspergillus fumigatus is one of the most studied species in clinical environments due to their high prevalence as contaminants in clinical material, while being responsible for invasive fungal infections among immunocompromised patients [24]. Their great toxicity is due to the production of specific mycotoxins, such as aflatoxin B1, ochratoxin A, and gliotoxin.…”