Bacteria are thought to learn how to fight antibiotics.

Bacteria have in their genome a wide variety of genes that allow them to develop their functions, but they also have other small DNA molecules like plasmids, circular DNA molecules. These genes are not essential for the bacteria, but they give them the necessary characteristics to be successful in difficult environments.

Do they not come from genes? Have you caught them?

Yes, they have genes that are essential in their genome, but in these plasmic circulars they have some complementary characteristics: those that give them the ability to survive against antibiotics, metals or molecular degradation, and those that have the ability to pass one another. How? When touched, the donor passes the plasmids to the recipient through a kind of yarn. This process is called conjugation. When it takes the plasmid it becomes resistant and also becomes a donor, extending resistance to antibiotics to the bacteria in its environment. Because some bacteria can take more than one plasmid, they become multiresistant to many antibiotics, superbugs.

Are these superbugs widespread?

Not very much, but every now and then you see a serious case. Two years ago, a woman died in the United States from an infection in India. Despite testing with him 26 antibiotics, no antibiotics were found that could slow down those bacteria. Bacteria in hospitals can be dangerous because in addition to being pathogenic, they are resistant.

Have we created them with misuse of antibiotics?

Bacteria have been on the planet for millions of years and have used antibiotics as a means of communication between them, also as a defense, but we use them as a weapon of destruction, as a weapon of imbalance. Without them, we couldn't have the modern life we have, we've had longer life expectancy, we've been allowed interventions and transplants -- but we didn't foresee the effects of abusive use. Since World War II, antibiotics have been used massively both in medicine and livestock, not only as a drug, but also preventively, to prevent animals from getting sick and growing faster. They have been used indiscriminately, so the amount of antibiotics being dumped and spread is very high. In water treatment plants, for example, many antibiotics are detected.

Are environmental resistance spreading?

Yes, that is why, in collaboration with NEIKER-Tecnalia, the UPV/EHU and the Institute for Climate Change Studies (BC3), we have launched the Joint Research Lab on Environmental Antibiotic Resistance (JRL) initiative to measure the presence of antibiotics in some significant CAPV sites. We can look at what bacteria exist and what resistance there is, so we can measure the risks of extending resistance between bacteria. We need a broad photograph to develop strategies against these resistant bacteria.

Is your proposal to hinder the spread of resistance?

Yes, there are special proteins that allow conjugation, the TrwB coupling proteins, that connect the plasmid to connect with the secretion channel. Our approach, in view of its functioning, is to seek ways of avoiding this, but it is not the only strategy, we must also control the presence of antibiotics.

What are the next steps?

We're at a critical time, in recent years we've learned a lot about this protein, and now we think it's time to start testing. On the one hand, we're looking for molecules that directly stop the protein, but another way is to try to find inhibitors in the process. We've identified a lot of molecules that we want to test with, let's see if they stop the process.

They say there are good microbes as well.

Most bacteria are beneficial to us. We do not yet know what the effect of microbiota is on health, but recent studies are showing that the imbalance of our microbiota influences autism, Alzheimer's and other diseases.

Do we create imbalances when taking antibiotics?

Always. Antibiotics attack bacteria, pathogenic or non-pathogenic. When we take them, almost always, we have diarrhea, because the microbiota of our intestines is damaged, and then it has to regain its balance by itself or with the help of probiotics.