Bacterial Community Shift Drives Antibiotic Resistance Promotion during Drinking Water Chlorination

Abstract

For comprehensive insights into the effects of chlorination, a widely used disinfection technology, on bacterial community and antibiotic resistome in drinking water, this study applied high-throughput sequencing and metagenomic approaches to investigate the changing patterns of antibiotic resistance genes (ARGs) and bacterial community in a drinking water treatment and distribution system. At genus level, chlorination could effectively remove Methylophilus, Methylotenera, Limnobacter, and Polynucleobacter, while increase the relative abundance of Pseudomonas, Acidovorax, Sphingomonas, Pleomonas, and Undibacterium in the drinking water. A total of 151 ARGs within 15 types were detectable in the drinking water, and chlorination evidently increased their total relative abundance while reduced their diversity in the opportunistic bacteria (p < 0.05). Residual chlorine was identified as the key contributing factor driving the bacterial community shift and resistome alteration. As the dominant persistent ARGs in the treatment and distribution system, multidrug resistance genes (mainly encoding resistance-nodulation-cell division transportation system) and bacitracin resistance gene bacA were mainly carried by chlorine-resistant bacteria Pseudomonas and Acidovorax, which mainly contributed to the ARGs abundance increase. The strong correlation between bacterial community shift and antibiotic resistome alteration observed in this study may shed new light on the mechanism behind the chlorination effects on antibiotic resistance.

Long-term field application of sewage sludge increases the abundance of antibiotic resistance genes in soil

“…Therefore, as bacterial diversity changes across soils, so do their associated ARGs, resulting in resistome that may respond to anthropogenic modulations that even do not possess obvious antibiotic-related properties (such as chemical fertilizer). The similar results were found in a recent study on drinking water system indicating that the major driver of antibiotic resistome alternation was bacterial community shift rather than MGEs reproduction or transference (Jia et al, 2015). In addition, our previous work also found that MGEs contributed only 2.6% of the resistome variation during sewage sludge composting .…”

“…An important finding from this work is that bacterial community shifts play a dominant role in shaping the antibiotic resistome in soil. Although, HGT via MGEs is often regarded as the underlying mechanism responsible for the resistome formation and spread under different ecological niches (Jia et al, 2015). In this study MGEs explained only 4.1% variation of ARGs.…”

Antibiotic resistance genes in an urban river as impacted by bacterial community and physicochemical parameters

“…Recent studies have demonstrated that variations in microbial community structure and mobile genetic elements (MGEs) were significantly correlated with ARG profiles in soil, sludge, and drinking water (Forsberg et al 2014;Jia et al 2015;Su et al 2015). However, riverine microbiota are exposed to a number of environmental factors including toxins, nutrients, hypoxia, and habitat alterations.…”

Inactivation Effect of Antibiotic-Resistant Gene Using Chlorine Disinfection

“…Armstrong et al [28] noted that the proportion of multiple antibiotic-resistant phenotypes increased during chlorination for Gram-positive cocci and Gram-negative, non-fermentative rods. In addition, Jia et al [29] revealed that a total of 151 antibiotic-resistance genes were detectable in the drinking water, and chlorination evidently increase their total relative abundance, while reducing their diversity in the opportunistic bacteria.…”