Manure from dairy cows, which have been treated with antibiotics, has been found to contain antibiotic resistance genes, according to research by scientists at Yale University, Connecticut. 

The findings were published in mBio, an online journal for the American Society for Microbiology, and suggests that cow manure could be a new source of antibiotic resistance genes, which transfer to bacteria in the soils where food is grown. This could mean that crops which are fertilised with manure from cattle treated with antibiotics could contain antibiotic resistant genes.

“Since there is a connection between antibiotic resistance genes found in environmental bacteria and bacteria in hospitals, we wanted to know what kind of bacteria are released into the environment via this route,” of manure fertilisation, says Fabienne Wichmann, lead study author and former postdoctoral researcher at Yale University.

He said the usage of manure on crops could lead to the antibiotic resistance bacteria might attach to the produce and end up being eaten by humans.

However, the researches said our knowledge of the identity, diversity, and patterns of distribution of these antibiotic resistance determinants remains limited.  The increasing prevalence of antibiotic resistance among bacteria is one of the most intractable challenges in 21st-century public health.