Dairy Cows and Calves: A Hidden Battle Against Drug-Resistant Bacteria

On some dairy farms in Western Australia, a silent struggle is taking place. It's not about milk production or pasture quality, but something much smaller and more sinister: drug-resistant bacteria.

Scientists recently took a closer look at this issue by studying E. coli bacteria found in the feces of lactating cows and young calves. They wanted to see how common these resistant bacteria were and what was making them so tough to treat.

The Study

• Samples Collected: Over a thousand fecal samples from 26 different farms.
• Findings:
• 7.3% of all samples had E. coli that could resist certain antibiotics.
• Calves had a higher rate of resistant bacteria (12.8%) compared to cows (3.2%).

Digging Deeper

The researchers examined the tiny loops of DNA called plasmids that these bacteria carry. These plasmids often hold the instructions for how to resist antibiotics.

• Multidrug Resistance: 95.1% of the E. coli showed resistance to multiple drugs.
• Common Resistance Gene: One called blaTEM was quite prevalent.
• Variability: The mix of resistance genes and plasmids varied from farm to farm, suggesting that the resistant bacteria might be spreading between farms.

The Concern

While the overall numbers might seem low, the presence of these resistant bacteria is a cause for concern. It highlights the need for careful antibiotic use in agriculture to prevent these tough bacteria from spreading further.