Intense farming raises risk of antibiotic resistance

Uganda's growing pig farming sector faces increasing risks of antimicrobial resistance (AMR), according to a study.

Resistance to antibiotics is likely to be more prevalent among pigs and farmers in semi-intensive farming systems compared with free-range holdings, the results found.

Their findings suggest a trend towards increased risk of antimicrobial resistance, as rising consumer demand for protein in low- and middle-income countries drives a need for intensive livestock production. 

A team of researchers led by the Roslin Institute spent a year working with 70 farmers and their pigs in Uganda. They studied a mix of urban and peri-urban settings, as a proxy for free-range and semi-intensive systems.

The team analysed hundreds of faecal samples to investigate levels of antibiotic resistance and the presence of key genes linked to AMR in the gut microbiomes of farmers and their pigs.

Results suggested that pigs in semi-intensive systems, where antibiotic use is typically higher, were 2.2 times more likely to display AMR than pigs in free-range systems. 

Farmers in urban systems also had higher levels of a key gene indicating increased resistance. 

AMR prevalence rose by 0.76 per cent each month over the course of the study, with potential transmission events more frequent in semi-intensive settings. 

The findings, published in Nature Communications Earth and Environment, highlight the significant variation in resistance levels based on farming practices, and the potential health risks associated with intensified farming.