Document Type
Article
Publication Date
3-2026
Publisher
American Society for Microbiology
Source Publication
Applied and Environmental Microbiology
Source ISSN
0099-2240
Abstract
Sanitary environments that undergo frequent cleaning and disinfection may harbor microbial communities with potential health risks. While biofilms in healthcare settings are well studied, comparatively less is known about sink-drain microbiomes in public and educational buildings, where hundreds of people may interact with shared sink fixtures. This study characterized the spatial and temporal heterogeneity of sink-drain biofilm microbiomes in academic buildings. We sampled 16 sinks from two buildings (four floors each, with sinks closest and furthest to the bathroom entrance), which are cleaned daily with quaternary ammonium compound (QAC) disinfectants, during periods of low and high student traffic (during and after academic breaks, respectively) across winter, spring, and summer. We observed significant spatial and temporal variations in microbial assemblages. Individual sinks accounted for 43% (PERMANOVA, P < 0.0001) of the variation in microbial communities. Microbiomes in each building were dominated by two genera, which together accounted for 30% of the community composition: Acinetobacter and Enhydrobacter (also classified as Moraxella) in the newer building, and Sphingomonas and Mycobacterium in the older building. Acinetobacter abundance varied seasonally and showed higher relative abundance during periods of high traffic. Metagenomic analysis of selected sinks revealed a high prevalence of qac genes and metagenome-assembled genomes (MAGs) harboring antimicrobial resistance genes (ARGs), including A. parvus. Notably, 34%–53% of qac genes were co-localized on contigs associated with mobile genetic elements. These findings suggest that disinfected sink drains serve as persistent reservoirs of diverse microorganisms and potentially mobile resistance elements.
Recommended Citation
Cruz, M. C.; Ruhal, R.; Lavin, J.; Bridwell, S.; Balasjin, N. Maghboli; Raasch, B.; Melton, R.; Mayer, Brooke K.; Marshall, Christopher; and Hristova, Krassimira R., " Acinetobacter spp. With Lower Susceptibility to Quaternary Ammonium Compounds Enriched in Microbial Communities of Frequently Used Sinks" (2026). Civil and Environmental Engineering Faculty Research and Publications. 420.
https://epublications.marquette.edu/civengin_fac/420
Comments
Published version. Applied and Environmental Microbiology, Vol. 92, No. 4 (2026): e0196825. DOI. © 2026 American Society for Microbiology. Used with permission.