exciting research on plasmid conjugation in Gram-positive bacteria

Biotechnology of Microorganisms
Centro de Biología Molecular “Severo Ochoa” CSIC-UAM (CBMSO)

Antibiotic resistance is an increasing problem world wide. Currently, more than 25,000 people die every year in the European Union to bacterial infections that are resistant to (multiple) antibiotics. Apocalyptic calculations predict that millions of peolpe may die in 2050 if the problem of antibiotic resistance is not addressed properly.

A major factor causing antibiotic resistance to increase rapidly is that antibiotic resistance genes are efficiently spreaded between bacteria via different mechanisms, collectively called Horizontal Gene Transfer. Of these, conjugation is by far the most important mechanism responsible for the dissemination of antibiotic resistance. Conjugation is the process by which a DNA element, -often a plasmid-, is transferred from one cell (donor) to a plasmid-free cell (recipient) via a tube that connects both cells.  

The gut microbiomes of humans and animals contain very high concentrations of bacteria that favor conjugation-mediated spread of antibiotic resistance. Indeed, the gut microbiome is a hotspot for the emergence and spreading of antibitioc resistance. A large fraction of the gut microbiome is composed by Gram-positive bacteria belonging to the phylum Firmicutes, in which antibiotic resistance is a problem. 

Hardly anything was known about plasmid conjugation in Firmicutes bacteria. That is why our lab began studying several years ago the native conjugative plasmid pLS20 of the Firmicute Bacillus subtilis. We started by determining the sequence of the plasmid, and have booked important progresses ever since. Currently, we are addressing various aspects of the conjugation pathway (transcriptional control, interaction with the host, cell-cell communication) using multiple techniques. We invite enthusiastic students to join our young group to form part of our exciting studies!   

Biomolecules & Cell D.
Molecular Biomedicine