AA tresnak

Text written in Basque and translated automatically by Elia without any subsequent editing. SEE ORIGINAL

Place of residence of the bacteria

The UPNA’s Institute of Agrotechnology is investigating how bacteria make their home, biofilm.

AA tresnak

A single cell organism without nuclei. That is, by definition, the bacterium. Despite its microscopic nature, its way of life is much more complex than expected; in fact, ants, such as bees or humans, live in the community or in colonies. To do this, he creates the biofilm, i.e. the place of residence. It grows adhered to any surface and this structure is very difficult to dismantle. The sliding cover
that is formed in the rocks of the streams, the viscous substance that we see inside the tube or the film that stains our teeth every day is a biofilm formed by bacteria. As well as those produced in prostheses, catheters and valves. Knowledge of the mechanisms
of microbial biofilm growth by bacteria is one of the lines of research of the group of the Institute of Agrotechnology of the Public University of Navarra. The goal is to destroy these colonies that are a source of infection or to encourage growth where necessary.

IÑIGO LASA; NUP: Our research is very molecular. We try to find out what genes the bacteria uses to do this, what the chemical structure is, and the ultimate goal would be for us to dismantle a biofilm that is already made, or to try to prevent the biofilm that is not yet made... If you put
a prosthesis on a person, we don’t want the bacteria on that prosthesis to attach and make the biofilm, because that would lead to infection, you have to remove the prosthesis...

To be a raw material for research, they take bacteria isolated from nature. In order to ensure their ability to biofilm, appropriate conditions must be created in the laboratory.

IÑIGO LASA; NUP: When we figure out how this bacterium makes biofilm in the lab, we try to figure out what genes this bacterium needs to make biofilm. For this, we make mutations, we take away the genes...

The mutation of the entire genome can eliminate the ability to make biofilm, but researchers want to know which genes are linked to this ability so that they can control it.

The bacteria and their mutations are placed in the wells of platelets. They are left until the biofilm is made. The results are then stained and it is observed whether the biofilm has been made or whether this ability has been lost.

IÑIGO LASA; NUP: Another way would be to do it on plates. We have found that the manner in which bacteria grow on the plates is related to the ability to make biofilm. There are two bacteria here. There is very little difference between the two bacteria, the difference is in one nucleotide between the two. This would be the mother, and this would be a mutant, a mutant where we've changed a nucleotide, and the only change of that nucleotide -- this bacterium has 3 million nucleotides and we've only changed one -- and that change makes the bacterium, now it's no longer capable of biofilm, and a very different colony is exposed on the plate.

A mutation that may be of interest is selected and the ability to make biofilm in fermentors is ensured.

JAIONE VALLE; CSIC: These are microfermenters. It is a biofilm production system. On the one hand, the medium is introduced and on the other hand, the additive is extracted.

We bring culture. These are bacteria grown in the test tube and placed in the microfermenter. At first, the spatula is clean. after 24 hours, there is biofilm. The bacteria have been added to the spatula, multiplied, exopolysaccharide has been released, and together they have produced biofilm.

Not all bacteria that live in a colony perform the same function. There is specialization, and this may be the key to the ability to create biofilm. In order
to discern the characteristics of bacterial genes that may be useful mutants for research, it is necessary to resort to microscopy.

IÑIGO LASA; NUP: Some people do some things, some people do other things, and we learn that under a microscope, and that's why we use some "whistle-blower" genes with different colors. each "whistleblower" lights up a different color, and looking at these colors we realize the city?? some bacteria do one thing and others do the other. The work is split.

ALEJANDRO TOLEDO; CSIC: One gene is marked by one color and the other by another. Here we can see that, in this bacterial population, most of them appear in green, but there are only a few that appear in red.

It is important to know the variability of the population. Often, that’s why treatments don’t work. We believe that all bacteria in a population are the same and that the treatment should kill them all, and that is not the case.

CRISTINA LATASA; NUP: Once we have found the mutation of a gene that prevents its ability to make biofilm, it is necessary to make tests that mimic the real conditions, i.e. ‘in vivo’. For example, with catheters.

They do tests on rats. The catheter is implanted under the skin and infected with bacteria. One introduces the bacterium of the wild-type strain and the other introduces the mutant. After two or three days, they retrieve the catheters, analyze the biofilms that have been produced, and see if they have remarkable differences.

Biofilms are the vital and protective sites for bacteria. Finding drugs or drugs that break down these biofilms or deprive bacteria of the ability to make biofilms is very important to avoid many cases of infection and contamination.