DISTRIBUTION OF ANTIBIOTIC RESISTANCE GENES IN THE ENVIRONMENT:
THE ROLE OF MINERAL FACILITATED HORIZONTAL GENE TRANSFER
Combining recent research across disciplines, I see evidence that minerals hold a high and unrecognized potential for enhancing the distribution of the ARg in the environment. Adsorption of ARg to minerals significantly increases the ARg’s lifetime and facilitates their distribution by sedimentary transport processes. In addition, minerals also serve as a) sites for horizontal gene transfer (HGT), b) platforms for microbial growth and, hence 3) act as hot spots for propagation of adsorbed ARg to other microbes. However, some minerals and ARg are bound more strongly than others and various bacteria have different affinities toward various minerals. Those variations in affinity are poorly quantified but vital for predicting the distribution of ARg in the environment.
Bacterial colony formation.
Image by Lisselotte Jauffred (collaborator from NBI)
The spread of antibiotic resistance genes (ARg) is a worldwide health risk1 and is no longer only a clinical issue. Vast reservoirs of ARg are found in natural environments2–4 such as soils, sediments and oceans. The emergence and release of ARg to the environment is in particular caused by extended use of antibiotics in farming, e.g. where the genes dissipate from the manure.5 Once in the environment, the ARg are surprisingly rapidly propagated. It is well known that the ARg are distributed to neighbour bacteria through processes of both cell sharing or through horizontal gene transfer (HGT) where one species acquirer resistance from another.6,7 Most HGT responsible for the spread of ARg are assumed to be through direct microbe-microbe contact. However, I find that the outcome of non-contact transfer is grossly underestimated. In the HGT mechanism called “Transformation”, free ARg in suspension or adsorbed to a mineral can be picked up and incorporated into non-related organisms. Considering that free DNA only can survive for a few weeks in sea- and freshwater environments,8–10 any HGT from free DNA can rightly be assumed to be local, but if the DNA gets adsorbed to a mineral, it can survive for several hundred thousands of years.11–14 If this also holds for ARg, then minerals offer a potent mechanism for distributing ARg through our environments my means of sedimentary processes.
PhD COURSE:
MEDICAL GEOBIOLOGY
19-23 August 2024 at the University of Copenhagen
As researchers and scholars, we stand at the intersection of numerous evolving challenges—environmental changes, emerging diseases, and the persistent riddle of antibiotic resistance. The solutions, we believe, are not embedded solely within the confines of traditional disciplines but instead lie at the confluence of various fields. This is where the burgeoning field of Medical Geobiology comes into play, a discipline that embodies the essence of interdisciplinary research and offers new perspectives on health and disease.
Why Medical Geobiology?
Medical Geobiology examines the evolutionary interplay between life forms, their environments, and the pressures that shape them both. It integrates principles from medical microbiology, evolutionary biology, biophysics, tumor biology, and geology, crafting a holistic view of health that transcends the boundaries traditionally set by these areas. This approach not only helps us understand present conditions but also, crucially, allows us to predict future health scenarios. Our course, "Evolutionary Processes Affecting Health – Medical Geobiology," is designed to train the next generation of scientists in these comprehensive, integrative techniques.
About the Course
Set to commence in August 2024 at the University of Copenhagen, this PhD course is tailored for individuals eager to push the boundaries of conventional scientific disciplines. Through a combination of lectures, student-led presentations, and intensive literature discussions, the course will delve into how evolutionary and ecological dynamics are crucial to understanding both ancient and contemporary health issues.
Participants will engage in case studies focusing on critical areas such as biofilm development, pollution impacts, and disease progression, enhancing their understanding through a hands-on approach that encourages both individual and collaborative learning experiences.
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More here: evolutionary geobiology consortium
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Funding
Funding
PhD School at the Faculty for health and medical sciences. University of Copenhagen