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Department of Nursing, Faculty of Nursing, Egh.C., Islamic Azad University, Eghlid, Iran.
Abstract: (8 Views)
Background: Airborne microorganisms in refrigerators may compromise the safety and quality of stored foods. This study assessed airborne bacterial and fungal contamination in dormitory and household refrigerators in Eghlid.
Methods: Airborne microorganisms were evaluated in 18 dormitory and five household refrigerators using the passive settle plate method. Nutrient agar and Eosin Methylene Blue (EMB) were used for bacterial isolation, and Sabouraud Dextrose Agar (SDA) for fungal and yeast isolation. Plates were exposed inside refrigerators for 1 h and incubated at 35 ± 2 °C for bacteria and 25 ± 2 °C for fungi and yeasts. Microorganisms were identified using standard microscopic and biochemical methods. Air contamination levels were expressed as the Index of Microbial Air Contamination (IMA) (CFU/plate/h).
Results: Bacterial contamination exceeded fungal and yeast contamination in both refrigerator types. Staphylococcus aureus was the predominant bacterium, and Gram-positive bacteria were more prevalent. Among fungi, Aspergillus spp. (29%) and Penicillium spp. (26%) were the most prevalent genera, whereas Rhodotorula spp. (75%) was the predominant yeast. IMA was higher in dormitory refrigerators (26.39 ± 11.66 CFU/plate/h) than in household refrigerators (12.0 ± 4.53 CFU/plate/h) (Mann-Whitney U test, P = 0.01).
Conclusion: Airborne microbial contamination was detected in refrigerators, with higher levels in dormitory refrigerators than in household ones.
Methods: Airborne microorganisms were evaluated in 18 dormitory and five household refrigerators using the passive settle plate method. Nutrient agar and Eosin Methylene Blue (EMB) were used for bacterial isolation, and Sabouraud Dextrose Agar (SDA) for fungal and yeast isolation. Plates were exposed inside refrigerators for 1 h and incubated at 35 ± 2 °C for bacteria and 25 ± 2 °C for fungi and yeasts. Microorganisms were identified using standard microscopic and biochemical methods. Air contamination levels were expressed as the Index of Microbial Air Contamination (IMA) (CFU/plate/h).
Results: Bacterial contamination exceeded fungal and yeast contamination in both refrigerator types. Staphylococcus aureus was the predominant bacterium, and Gram-positive bacteria were more prevalent. Among fungi, Aspergillus spp. (29%) and Penicillium spp. (26%) were the most prevalent genera, whereas Rhodotorula spp. (75%) was the predominant yeast. IMA was higher in dormitory refrigerators (26.39 ± 11.66 CFU/plate/h) than in household refrigerators (12.0 ± 4.53 CFU/plate/h) (Mann-Whitney U test, P = 0.01).
Conclusion: Airborne microbial contamination was detected in refrigerators, with higher levels in dormitory refrigerators than in household ones.
Type of Study: Original Article |
Subject:
Environmental Health, Sciences, and Engineering
Received: 2026/04/4 | Accepted: 2026/06/10
Received: 2026/04/4 | Accepted: 2026/06/10
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