Isolation of fungi in indoor air environment of selected air-conditioned and non-airconditioned wards in a public tertiary hospital in Metro Manila, Philippines

Background and Objectives@#The hospital as health care facility has also become a source of infection that provides a place for different microbiological agents such as fungi. Exposure to these organisms is specifically detrimental to highly immunocompromised in-house patients. This study aimed to 1) detect the presence of fungi in a public tertiary hospital in Metro Manila; 2) determine the dominating fungal organism; and 3) describe the environmental conditions and physical factors affecting the proliferation of fungal organisms. @*Methodology@#Eight sampling sites were selected for this study. The hospital main lobby was the comparison site for the three non-air-conditioned surgery wards (NACWs) while the fourth level nurse station is the comparison site for the air-conditioned wards (ACWs). Meteorologic conditions such as environmental temperature and relative humidity were also determined. Andersen air sampler was utilized to conduct the environmental indoor air sampling. A total of 98 malt extract agar supplemented with chloramphenicol (0.01%) plates were utilized for the duplicate sampling in eight sites. After three to five days of incubation at 37° C, the isolated fungal organisms were culturally and morphologically characterized. @*Results@#Seven fungal organisms were isolated from the indoor air sampling conducted namely: Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, Curvularia sp., Penicillium sp., Alternaria sp. and Rhizopus sp.). The most dominant fungal species among the NACWs was A. niger. On the other hand, A. fumigatus was the most observed isolate among the ACWs. The air-conditioned wards showed a higher number of fungal isolates. In particular, A. fumigatus and A. flavus colonies in the ACWs were evidently higher than in the NACWs. @*Conclusion@#The ubiquitous nature of the Aspergillus species and slow settling rate due to small spore size make it the most dominant fungal organism retrieved in the air sampling conducted. No strict numerical guidelines were available for the spore counts of Aspergillus species to assess contamination rate. However, according to the Health Protection Surveillance Centre, 2018, the values of CFU/m³ of most of the isolates not only by Aspergillus species showed non-compliance with the threshold level documented.

Depositional characteristics of atmospheric polybrominated diphenyl ethers on tree barks

OBJECTIVES: This study was conducted to determine the depositional characteristics of several tree barks, including Ginkgo (Ginkgo biloba), Pine (Pinus densiflora), Platanus (Platanus), and Metasequoia (Metasequoia glyptostroboides). These were used as passive air sampler (PAS) of atmospheric polybrominated diphenyl ethers (PBDEs). METHODS: Tree barks were sampled from the same site. PBDEs were analyzed by highresolution gas chromatography/high-resolution mass spectrometer, and the lipid content was measured using the gravimetric method by n-hexane extraction. RESULTS: Gingko contained the highest lipid content (7.82 mg/g dry), whereas pine (4.85 mg/g dry), Platanus (3.61 mg/g dry), and Metasequoia (0.97 mg/g dry) had relatively lower content. The highest total PBDEs concentration was observed in Metasequoia (83,159.0 pg/g dry), followed by Ginkgo (53,538.4 pg/g dry), Pine (20,266.4 pg/g dry), and Platanus (12,572.0 pg/g dry). There were poor correlations between lipid content and total PBDE concentrations in tree barks (R2=0.1011, p =0.682). Among the PBDE congeners, BDE 206, 207 and 209 were highly brominated PBDEs that are sorbed to particulates in ambient air, which accounted for 90.5% (84.3-95.6%) of the concentration and were therefore identified as the main PBDE congener. The concentrations of particulate PBDEs deposited on tree barks were dependent on morphological characteristics such as surface area or roughness of barks. CONCLUSIONS: Therefore, when using the tree barks as the PAS of the atmospheric PBDEs, samples belonging to same tree species should be collected to reduce errors and to obtain reliable data.

Detection of airborne psychrotrophic bacteria and fungi in food storage refrigerators

The purpose of this study was to determine the microbiological air quality (psychrotrophic bacteria and airborne fungi) and distribution of fungi in different types of ready-to-eat (RTE) food-storage refrigerators (n=48) at selected retail stores in the city of Edirne, Turkey. Refrigerators were categorized according to the type of RTE food-storage: meat products, vegetables, desserts, or a mix of food types. Microbiological quality of air samples was evaluated by using a Mas-100 Eco Air Sampler. Four refrigerators (all containing meat products, 8.3%) produced air samples with undetectable microorganisms. The highest detected mean value of airborne psychrotrophic bacteria and fungi was 82.3 CFU/m³ and 54.6 CFU/m³, respectively and were found in mixed-food refrigerators. The dominant airborne fungal genera found were Penicillium (29.0%), Aspergillus (12.0%), Mucor (9%), Cladosporium (8%), Botyrtis (7%), and Acremonium (6%). By definition, RTE food does not undergo a final treatment to ensure its safety prior to consumption. Therefore, ensuring a clean storage environment for these foods is important to prevent food-borne disease and other health risks.

Distribution of Fungus Spores in Indoor and Outdoor Air / 대한의진균학회지

The number of fungus spores in the air is greater compared to that of pollen and also is less influenced by season. Recently there is increasing interest in the role of fungus as an allergen and causative factor of sick building syndrome. There are several kinds of samplers for the collection of fungus spore in outdoor and/or indoor air such as Durham sampler, rotorod sampler, personal volumetric air sampler, seven-day recording volumetric spore trap, and portable air sampler for agar plates. Because personal volumetric air sampler is small, rechargeable and volumetric equipment, it is suitable for air sampling indoors. Portable air sampler for agar plates is useful for fungus culture from indoor and outdoor air. According to the results of our study on distribution of fungus spores in indoor and outdoor air by using personal volumetric air sampler, Cladosporium and Leptosphaeria were common spores in indoor and outdoor air. The number of spores in indoor air was closely correlated with that in outdoor air. Therefore it would be necessary to establish a standard method for collecting the fungus spores. We need to perform the nationwide study on distribution of fungus spores using this method, and to evaluate the allergenicity of fungus spores.