Unearthing Antibiotic Resistance Associated with Disturbance-Induced Permafrost Thaw in Interior Alaska

Abstract

Monitoring antibiotic resistance genes (ARGs) across ecological niches is critical for assessing the impacts distinct microbial communities have on the global spread of resistance. In permafrost-associated soils, climate and human driven disturbances augment near-surface thaw shifting the predominant bacteria that shape the resistome in overlying active layer soils. This thaw is of concern in Alaska, because 85% of land is underlain by permafrost, making soils especially vulnerable to disturbances. The goal of this study is to assess how soil disturbance, and the subsequent shift in community composition, will affect the types, abundance, and mobility of ARGs that compose the active layer resistome. We address this goal through the following aims: (1) assess resistance phenotypes through antibiotic susceptibility testing, and (2) analyze types, abundance, and mobility of ARGs through whole genome analyses of bacteria isolated from a disturbance-induced thaw gradient in Interior Alaska. We found a high proportion of isolates resistant to at least one of the antibiotics tested with the highest prevalence of resistance to ampicillin. The abundance of ARGs and proportion of resistant isolates increased with disturbance; however, the number of ARGs per isolate was explained more by phylogeny than isolation site. When compared to a global database of soil bacteria, RefSoil+, our isolates from the same genera had distinct ARGs with a higher proportion on plasmids. These results emphasize the hypothesis that both phylogeny and ecology shape the resistome and suggest that a shift in community composition as a result of disturbance-induced thaw will be reflected in the predominant ARGs comprising the active layer resistome.

Special Issue “Antimicrobial Resistance: From the Environment to Human Health”

“…Another study also published in this special issue addresses how soil disturbance, and the subsequent shift in community composition, will affect the types, abundance, and mobility of antibiotic resistance genes (ARGs) that compose the active layer resistome by assessing resistance phenotypes through antibiotic susceptibility testing, and analyzing types, abundance, and mobility of ARGs through whole genome analyses of bacteria isolated from a disturbance-induced thaw gradient in Interior Alaska. This study emphasizes the hypothesis that both phylogeny and ecology shape the resistome and suggest that a shift in community composition as a result of disturbance induced will be reflected in the predominant ARGs comprising the active layer resistome [5]. In a different study, several antibiotic-resistant bacteria (ARB) were isolated from the mangroves in Kerala, India showing that MDR with strong biofilm formation is prevalent in natural habitat and if acquired by deadly pathogens may create a highly negative impact in public health [6].…”

Permafrost as a potential pathogen reservoir

“…There are several reports about prevalence of antibiotic resistance genes in permafrost bacteria [61][62][63] that could make known pathogens more problematic. Antibiotic resistance poses a threat to human health by reducing the efficacy of antibiotic treatments.…”

How Do the Players Play? A Post-Genomic Analysis Paradigm to Understand Aquatic Ecosystem Processes

“…This has prompted speculation that local permafrost conditions affect the composition of the resistome and selection for AMG mobility, and that as thawing dynamics (i.e., thaw slumping into adjacent waters, increased element mobility, dissolution etc.) impact microbial community structure, the transmission of AMGs will similarly be affected (Haan and Drown, 2021). While these initial findings are of importance, the impact will not be confirmed until metatranscriptomic analysis confirms plasmid mobility and/or ARG activity, and metabolomics or proteomics confirms alteration in community functional profile.…”