Comparison of survivability of Staphylococcus aureus and spores of Aspergillus niger on commonly used floor materials.
BACKGROUND
The survivability of Staphylococcus aureus and spores of Aspergillus niger was compared on 5 common floor materials.


METHODS
Floor materials were inoculated with a known concentration of S aureus and spores of A niger on day 0. Their survivability was measured on days, 2, 7, 14, and 28 by bulk rinsate method and enumerated using culture-based method.


RESULTS
The difference in change of S aureus levels was statistically significant for all tested days (P < .001) for all floor materials. Vinyl composition tile (VCT) and porcelain tile (PT) had statistically similar survivability and differed statistically from carpets. On both VCT and PT, positive growth for S aureus occurred by day 2 (1-1.7 log10), declined slightly (0.1 to -0.2 log10) by day 7, and remained positive until day 28. However, S aureus was undetected by day 7 on both carpets. A niger spores were undetected on residential broadloom carpet and rubber-backed commercial carpet after day 2 but survived on VCT, PT, and wood until day 28.


CONCLUSIONS
Floor materials with hard and smooth surfaces, such as VCT and PT, can allow survival of S aureus and A niger for up to 4 weeks. It may imply that floor materials can play a major role in preserving microbial contaminants in the built environment.
Division of Environmental Health Sciences, College of Public Health, The Ohio State University, Columbus, OH.
Mridula
M
Gupta
Division of Environmental Health Sciences, College of Public Health, The Ohio State University, Columbus, OH. Electronic address: bisesi.12@osu.edu.
Michael
M
Bisesi
Division of Environmental Health Sciences, College of Public Health, The Ohio State University, Columbus, OH; Department of Food Science & Technology, The Ohio State University, Columbus, OH.
Jiyoung
J
Lee
D001234:Aspergillus niger / Q000302:isolation & purification* / Q000502:physiology; D015169:Colony Count, Microbial; D004783:Environmental Microbiology; D005430:Floors and Floorcoverings; D050296:Microbial Viability; D013172:Spores, Fungal / Q000302:isolation & purification* / Q000502:physiology; D013211:Staphylococcus aureus / Q000302:isolation & purification* / Q000502:physiology; D013997:Time Factors
Aspergillus niger; Built environment; Carpet; Floor materials; Spore; Staphylococcus aureus; Survivability