図書の微生物汚染

抄録

We investigated the state of contamination by microorganisms in 173 library books and found the surfaces of the books to have contaminants ranging from <12 to 4.9 x 10 ⁴ colony-forming units (cfu)/ cover. We found 81.5% of the books tested to have the range of contaminant load counting 0 to 960 cfu/cover; the mean number of contaminant ± standard deviation was 1,261 ± 4,482 cfu/cover. The main contaminants included some environmental bacteria, such as Bacillus atrophaeus and Bacillus cereus, and a skin microbial flora consisting of coagulase (-) staphylococci and Micrococcus spp. On the other hand, methicillin-sensitive Staphylococcus aureus was detected in 4 (2.3%) of the 173 books, and the numbers ranged from 12 to 420 cfu/cover. We did not detect any coliform bacteria or Pseudomonas aeruginosa on the books that were sampled. We found the library books investigated in this study relatively clean.