Antibiotic resistance is a global threat that claims high morbidity, mortality and economic costs. It is aggravated by the global dissemination of human and animal pathogens harboring mobile antibiotic resistance genes (ARGs), in particular those conferring resistance to colistin, and beta-lactams including carbapenems. These are considered as antibiotics of last resort for human infections due to multi-drug resistant bacteria. The transfer of these ARGs across microorganisms broadens their range of host species, allowing a wide existence of these genes in various biomes/habitats. Understanding the myriad pathways by which antimicrobial-resistance genes (ARGs) spread across biomes is essential to counteract the global menace of antimicrobial resistance.
Antwerp, 18 November 2022 - On the World Antibiotic Awareness Day, the Laboratory of Medical Microbiology (LMM), part of the Vaccine & Infectious Disease Institute at the University of Antwerp, Belgium, in collaboration with researchers from the European Bioinformatics Institute, Cambridge, United Kingdom published a new study identifying ‘hotspot’ biomes for development of effective and targeted countermeasures against ARG spread. This research provides a global map of antibiotic resistance genes (ARG) distribution and identifies biomes wherein interventions aimed at disrupting ARGs dissemination are likely to be most effective.
Prior studies on ARGs have mainly focused on specific biomes (e.g., human gut, sewage, farms, estuary sediments and soil), but a global One Health (Human–Animal Environment) ARG landscape across diverse biomes (human, animal, plant, anthropogenic environment and natural environment) was lacking. Comparing ARG profiles across diverse biomes provides an unique opportunity to comprehensively understand global prevalence and the preferred niches of ARGs, and is a prerequisite for the fight against ARG spread.
The new study presents a comprehensive screening of publicly available and global metagenomic datasets (until October 2019) to compile a landscape of the distribution of genes encoding resistance to some of the most widely used and last-resort antibiotics, beta-lactams including carbapenems and to colistin. Researchers from LMM studied diverse biomes in a global context representing diverse proximities to hotspots of antibiotic use and identify a decreasing frequency of these ARGs from human-associated biomes, to anthropogenic and natural biomes with a deterministic distribution pattern.
The findings show that the global distribution of the targeted ARGs follows a non-random pattern and is primarily shaped by the biomes where they exist and their potential host species, with transmission preferentially occurring between biomes with similar characteristics within defined ecological boundaries.
Professor Surbhi Malhotra, group leader and corresponding author of the study, says “Given the global nature of the (antimicrobial resistance) problem, our results could be considered truly meaningful only if the analysis was performed on a global scale. This was made possible due to the steep increase in sophisticated metagenomic sequencing over the last 15 years and the availability of approximately 18,000 such datasets across biomes, countries, and continents that were analyzed in this study. Our next attempt would be to use our results to develop relevant interventions aimed at decreasing ARG loads in high-density biomes”.