Effects of the biocides on the culturable house dust-borne bacterial compositions and diversities

ABSTRACT

Biocides are used ubiquitously in indoor environments, but knowledge is limited about how they impact indoor bacterial compositions and diversities. In this study, an in vitro experiment was conducted to demonstrate changes in the culturable house dust-borne bacterial compositions and diversities by exposures to three biocides of CuSO₄ (CUS), triclosan (TRC), or benzalkonium chloride with respective concentrations of 90, 45, and 0.1 μg ml⁻¹. The high-throughput sequencing was used to characterize the bacterial compositions and diversities. The α diversity analysis showed reductions in the species richness and evenness by exposures to CUS and TRC (p < 0.05, Wilcoxon signed rank tests). The β diversity analysis revealed the significant changes in the community memberships for CUS and TRC (p < 0.05, P-tests based on the Jaccard indices), which were thought due to selective bacterial inhibitions. The taxonomic analysis found the inhibitions of Enterococcus, Peptoniphilus, Anaerococcus, Finegoldia,Clostridium sensu stricto, and Stenotrophomonas. The findings of the present in vitro study provide important insights into how use of biocides in indoor environments affects bacterial compositions and diversities. Future in situ research is warranted to confirm how they impact indoor microbial compositions and diversities, which are thought to be important for human health.

KEYWORDS:

• high-throughput sequencing
• 16S rDNA
• triclosan
• copper (II) sulfate
• benzalkonium chloride
• next-generation sequencing

Funding

This research was supported by Social Service R&D research (No. HI13C1436) of the Ministry of Health & Welfare.