The University of Nottingham has said livestock farms are being studied as potential sources of resistant infections in animals and humans.
Scientists from the university are now closer to understanding how bacteria like E.Coli and salmonella on farms share genetic material that makes them resistant to antibiotics.
In the latest study, scientists looked to demonstrate that different bacteria species are able to share genetic material associated with antimicrobial resistance (AMR).
With shared AMR-associated genetic material, the bacteria species end up implementing similar resistance mechanisms.
The University of Nottingham said the discovery has “important implications” as it affects understanding of AMR, and poses further challenges to the implementation of solutions for surveillance and treatment/control.
“Livestock farms, their surrounding environments and food products generated from husbandry, have been highlighted as potential sources of resistant infections for animals and humans.
“In livestock farming, the misuse and overuse of broad-spectrum antimicrobials administered to reduce production losses, is a major known contribution to the large increase and spread of AMR,” a spokesperson for the university said.
Study
Published in Nature Communications, the study looks at two bacteria found in food animals: E.coli and salmonella.
Both bacteria show high levels of drug resistance, are common in farming settings, have high levels of transmissibility to humans and cause food poisoning.
The team collected 661 E. coli and salmonella bacteria isolates from chickens and their environments in 10 Chinese chicken farms and four abattoirs over a two-and-a-half year period.
They carried out a large-scale analysis using conventional microbiology DNA sequencing and data-mining methods powered by machine learning.
Dr. Tania Dottorini of the School of Veterinary Medicine and Science at the University of Nottingham, is the lead researcher on the study.
“These species of bacteria (E.coli and salmonella) can share genetic material both within, and potentially between species, a way in which AMR is spread.
“That is why understanding the extent to which these bacteria are within the same environment, and importantly, the same host, can co-evolve and share their genome could help the development and more efficient treatments to fight AMR,” she said.
Antimicrobial resistance
The main findings indicate that E. coli and salmonella enterica co-existing in the chicken gut, compared to those existing in isolation, feature a higher share of AMR-related genetic material.
The bacteria implement more similar resistance and metabolic mechanisms and are also more likely the result of a stronger co-evolution pathway.
“The insurgence and spread of AMR in livestock farming is a complex phenomenon, arising from an entangled network of interactions happening at multiple spatial and temporal scales.
“Investing in data mining and machine learning technologies capable to cope with large scale, heterogenoeus data is crucial to investigate AMR , in particular when considering the interplay between cohabiting bacteria, especially in ecological settings where community-driven resistance selection occurs.
“Overall, this work has also demonstrated that the investigation of individual bacterial species taken in isolation may not provide a sufficiently comprehensive picture or the mechanisms underlying insurgence and spread of AMR in livestock farming, potentially leading to an underestimation of the threat to human health,” the lead researcher said.
