How do bacteria spread their resistance to antibiotics? – Techno-Science.net

Understanding how certain bacteria become resistant to antibiotics is an important public health issue today. A key mechanism for the spread of resistance is the transfer of genetic material between bacteria. In a paper published in the journal Nature Communication, scientists have developed genetic reporters that allow transmission to be visualized live under a microscope, showing that this very fast mechanism is spatially and temporally organized.

In recent years, the global emergence of multidrug-resistant bacteria has become a major public health concern and a priority for microbiological research. The spread of this resistance is mainly due to the ability of bacteria to exchange genetic material that carries resistance to antibiotics. The fundamental study of DNA transfer processes therefore remains necessary to find new solutions to combat the spread of antimicrobial resistance and prevent the emergence of new multidrug-resistant bacteria.

Scientists were able to film the DNA transfer process in real time at the single-cell scale, revealing the spatial and temporal timeline of the capture event. In the case of the bacterium Escherichia coli, for example, it has been shown that in just two minutes the DNA can be completely transferred from one bacterium to another and that in less than 1 hour the genetic material can be transferred autonomously to another bacterium, resulting in a rapid and exponential spread of the bacterium resistance. Thanks to real-time monitoring by microscopy, this study also reveals a molecular strategy of these mobile DNA elements that temporally and sequentially program the production of the factors involved in their establishment, maintenance and dissemination.

Microscopy to understand the spread of resistance between bacteria

Video: Real-time microfluidic imaging showing the production of a green protein (SsbF-sfGFP) from the plasmid after the plasmid was transferred into the red recipient bacterium.

The recipient bacterium produces a red protein (ParB-mCh) which, in the absence of the plasmid, diffuses into the cytoplasm and forms a concentrated red focus once the plasmid has been transferred and established in the recipient cell.

The movie shows multiple fluorescence channels of the same image frame. Merge: phase contrast, SsbF-sfGFP green fluorescence and ParB-mCh red; SsbF-sfGFP ParB-mCh: green and red fluorescence, ParB-mCh: red fluorescence; SsbF-sfGFP: green fluorescence.

Learn more:
Real-time visualization of intracellular dynamics of conjugative plasmid transfer
Agathe Couturier, Chloé Virolle, Kelly Goldlust, Annick Berne-Dedieu, Audrey Reuter, Sophie Nolivos, Yoshiharu Yamaichi, Sarah Bigot, and Christian Lesterlin.
nat. Com. 2023. DOI:10.1038/s41467-023-35978-3.