Swedish scientists from Chalmers University of Technology and the University of Gothenburg have identified bacteria with new latent antibiotic resistance genes in many natural environments, including human and animal microbiomes. The results of the study are published in the journal Microbiome.

The researchers hypothesized that there are many bacteria in the environment with genes that promote antibiotic resistance in microorganisms, making antibacterial treatment ineffective. The combination of these genes is called a resistome. Separately, the so-called latent resistance genes are singled out, which are absent in modern databases and are poorly characterized, which does not allow specialists to correctly assess the risks of the spread of antibiotic-resistant pathogenic microorganisms.

The scientists analyzed 630 billion bacterial DNA sequences in more than 10,000 metagenomic samples isolated from a variety of environments, including the human gut microbiome, human skin microbiome, soil, and wastewater treatment plants.

Related materials:Nothing to breathe. How oxygen affects the aggressiveness of cancerous tumors

It turned out that latent resistance genes predominated in all samples. Among the most common genes that form a nuclear resistome, both well-characterized and latent ones were identified. In addition, some of the frequently occurring latent genes have been found in multiple pathogens, including Pseudomonas aeruginosa, Salmonella enterica, and Campylobacter spp.

Researchers have characterized several latent resistance genes that are common across environments and present in human pathogens. It turned out that they are located on mobile genetic elements - DNA sequences that can move within the bacterial genome. These include integrative conjugative elements that are able to cut themselves out of chromosomes and enter other bacteria through horizontal transfer.

Wastewater microbiomes have surprisingly high resistance, making this environment potentially favorable for the spread of latent resistance genes. This is a huge reservoir in which antibiotic-resistant pathogens can develop.