Scientists from the University of Saskatchewan, Canada, have found a new antibiotic-resistant gene in the bacteria of feedlot water bowls used in cows and bulls farms. This gene can inactivate an entire class of drugs called macrolides often used to treat tonsillitis in humans and bovine respiratory disease in cows. This gene is commonly found in the microbiome of many farm animals, but not until now its dangerous resistant properties have been identified.
The study, titled “A neglected and emerging antimicrobial resistance gene encodes for a serine-dependent macrolide esterase”, was published in the journal PNAS in February 2023. Poonam Dhindwal, Charis Thompson, Daniel Kos, and Antonio Ruzzini, the authors of the study, recommend increased surveillance of antibiotic-resistant genes to guide clinical practice, as well as improving the system of analysis to identify more resistant genes based on how they pass between pathogens.
More than 1.2 million human deaths worldwide are attributed to antibiotic resistance, and one of the leading drivers is the overuse of antibiotics in factory farms. Bacteria with resistant genes spread on farms as they accumulate in the soil and the water, so animals then spread it by moving around the farm. According to a paper titled “Antibiotic use in farming set to soar despite drug-resistance fears” published in Nature in 2023, antibiotic use in farming is set to increase by 8% from 2020 to 2030, which will increase the chances of antibiotic-resistant pathogens spreading further. Unfortunately, only a few countries have restricted or banned the used of antibiotics to promote growth and prevent disease in farms (the UK cut antimicrobial use in farm animals by 52% between 2014 and 2020). The US has no system for tracking the use of antibiotics on farms and sales of antibiotics for animals in farms are rising now after a brief fall between 2015 and 2017.