Antibiotic-resistant Salmonella 'spread by intensive pig farming'

By William Dodds

- Last updated on GMT

Researchers conducted DNA analysis of 362,931 strains of bacteria. Credit: Getty / jmsilva
Researchers conducted DNA analysis of 362,931 strains of bacteria. Credit: Getty / jmsilva

Related tags Agriculture

Changes made to pig farming practises during the 20th century led to the spread of antibiotic-resistant Salmonella around the world, new research suggests.

An international study led by researchers at the University of Warwick provides evidence that the adoption of intensive farming practices over the last century enabled the spread of Salmonella enterica bacteria.

Salmonella enterica is a type of bacteria responsible for millions of illnesses every year and can contaminate food, water and food processing facilities.

The bacteria is able to enter the food supply chain, with pork being a major source of infections. Meanwhile, the pathogen can ‘jump’ from pigs to humans, causing severe and potentially fatal illnesses.

Prior to the research the impact of modern farming methods and global trade on the prevalence of antibiotic resistant Salmonella remained unclear, but DNA analysis of 362,931 strains of bacteria led to the detection of nine Salmonella populations that are abundant in pigs.

The scientists linked the expansion of the bacteria with two historical events in the 20th century – first the development of intensive pig farming in the early 1900s and second the overuse of antibiotics after the 1960s. They added that Europe and the USA contributed the most to international transmissions of the bacteria.

“Our study has shown how the global trade of pork has played a key role in the evolution of Salmonella – posing direct threats to food safety worldwide,” ​said Professor Sascha Ott from Warwick Medical School.

Honorary research fellow at the University of Warwick, Dr Zhemin Zhou, added: “As the majority of Salmonella genomes included were from developed countries, with limited data from developing countries, especially those in South America and Africa, further research should look at these understudied regions. This should improve knowledge of Salmonella evolution and aid efforts to prevent illnesses caused by this pathogen."

Meanwhile, Dr Laura Baxter, senior bioinformatician at University of Warwick, warned that “Salmonella is not likely to be the only pathogen that has been reshaped by human agricultural practices”.

“We should also investigate the evolution of other pathogens,”​ Baxter concluded.

In other news, a 50-year-old man has been killed following an incident at a soft drinks production facility in Gloucestershire.

Related topics Food Safety Meat, poultry & seafood

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