Hospital Plumbing Sink Biofilm Metagenome

Abstract:The increase of antimicrobial resistant bacteria is considered one of the critical issues of our time. Wastewater is a rich source of complex bacterial communities where bacteria can share genes of antimicrobial resistance through horizontal gene transfer. Hospital wastewater premise plumbing systems may act as an ideal reservoirs for environmental and pathogenic bacteria to interface and exchange genes of antimicrobial resistance. Highly resistant Enterobacterales are of the greatest concern because they not only cause human infections but can also thrive in the environment and have shown to transmit from sink drains to patients. Replacement of contaminated plumbing may be the most intuitive and widely deployed response once highly resistant potentially pathogenic bacteria are identified in a sink drain. Here we show using shotgun metagenomic sequencing of sink drain biofilms (in 6 intensive care patient rooms, 36 subsamples) paired with microbial culture analysis, an evident shift of biofilm community structure towards increased abundance of Enterobacteriaceae, while the community richness and evenness remained the same in the newly replaced sink plumbing. Significant increase in resistome load and abundance of clinically relevant resistance and typically mobile genes in the newly replaced plumbing was observed. Findings from our pilot study demonstrate that exchanging contaminated plumbing for new plumbing may actually have the unexpected consequence of increased abundance of Enterobacterales and genes of antimicrobial resistance in the sink drains.