Microbial contamination of books in the library

Abstract

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.