A new study showed that scientists developed the ability of bacteria to swap genetic material with each other can directly affect the emergence and spread of globally important infectious diseases. The study was published in Nature Communications.

This Genetic material is known as 'horizontal gene transfer', this phenomenon is understood to have played a role in developing the global antimicrobial resistance (AMR) crisis. However, the dynamics of AMR transfer through bacterial populations and its direct impact on human disease is poorly understood. The combined epidemiological information from cases together with whole genome sequencing analysis of bacteria from those cases.

They looked at three epidemics in England of the globally important diarrheal pathogen Shigella between 2008 and 2014. The findings found that English epidemics of these typically-rare pathogens were associated with resistance to the antibiotic azithromycin and that many of the co-circulating Shigella strains carried the azithromycin resistance genes on the same plasmid.

Plasmids are small circular DNA molecules that can be transferred horizontally between bacteria. They contain the bacterium's genetic material but are separate from the cell's chromosomal DNA. By combining this genomic information from the different Shigella strains with the epidemiological information about the outbreaks, the researchers were able to demonstrate that the transfer of the plasmid was facilitating new epidemics.

Antimicrobial resistance (AMR) is a global epidemic. In 2014 the World Health Organisation advised that the antibiotics we are reliant on are in danger of becoming obsolete. It is estimated that by the year 2050, deaths attributed to antimicrobial resistance will claim up to ten million lives per year, surpassing those lost to cancer.

Dr Kate Baker said: "Through this study, they have been able to show that horizontal gene transfer can rapidly facilitate new epidemics of important pathogens. "This means that in all areas of AMR research, public health management and surveillance we need to be analysing our pathogen genomes in great detail to understand the epidemiology of antimicrobial resistance."