top of page

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.

bug colony.png

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.

KKS

Search

- Apr 21, 2022

2 Days of biofilm discussions

Biofilm workgroup meeting in Helsingør 2022 #DanishBiofilmWorkshop

Organizers: Thomas Bjarnsholt and Mette Burmølle

What a treat to be updated on current knowledge on biofilm diagnostics, evolution, social interactions, adhesion and molecular mechanisms.

Saghar presented a poster on her work on biofilms on:

“Biofilm formation gene expression of Pseudomonas aeruginosa downregulates in response to sublethal antimicrobial photodynamic inactivation”

Taru gave and oral presentations about the use of Raman for profiling ARg:

“Profiling antibiotic resistance in Escherichia coli strains displaying differential antibiotic susceptibilities using Raman spectroscopy”

I presented her and Liselotte’s ideas for addressing the question of mineral facilitated propagation of antibiotics resistance genes:

"Distribution of antibiotic resistance genes in the environment: The role of micro-environments and interfacial geochemistry for ARg-transfer dynamics"

It was excellent to talk to colleagues and an IRL audience again. Also, I had not realized how I missed mingling in poster sessions.

Thanks to the organizers for a great meeting (and to VILLUM FONDEN for funding our research), we left with a lot of food for thoughts!

Recent Posts

Application of interfacial geochemistry as a tool to advance SedaDNA research

International day for women and girls in science

Meet our newly funded interdisciplinary research project: Importance of extracellular DNA for evolution: a missing link?

Bình luận

bottom of page