A new study raises serious concerns about the safety of raw milk, revealing alarming levels of antibiotic-resistant bacteria present in commonly consumed cow and sheep milk in Pakistan. The findings, published in the journal PLOS One, highlight a significant public health risk linked to the widespread practice of consuming unpasteurized milk in many parts of the world.
Over 95% of milk consumed in Pakistan is raw — meaning it hasn’t been heated to kill potentially harmful bacteria. This practice leaves consumers vulnerable to contamination stemming from improper handling or infections within cows, known as subclinical mastitis. While often invisible to the naked eye, this condition weakens cows and directly contaminates their milk with bacteria.
The overuse of antibiotics to manage these often-hidden infections has fueled a troubling trend: the emergence of multidrug-resistant bacterial strains. These superbugs can then easily be passed from contaminated milk to humans, threatening both individual and public health.
This study focused on Staphylococcus epidermidis, a bacteria commonly associated with subclinical mastitis. While usually harmless on human skin, this bacterium can pose a serious threat when it carries resistance to multiple antibiotics.
Researchers collected 310 milk samples — half from cows and half from sheep — and screened them for both the presence of Staphylococcus epidermidis and signs of subclinical mastitis. The results were concerning: almost one-quarter of the samples indicated subclinical mastitis, and approximately 13% harbored this dangerous bacteria.
Even more alarming was the resistance profile of the isolated Staphylococcus epidermidis. Nearly all (95%) displayed resistance to penicillin and erythromycin, with half resistant to three or more antibiotics. This rampant resistance fuels fears that these strains could transfer their antibiotic-resistant genes to even more dangerous pathogens like Staphylococcus aureus — responsible for serious infections including MRSA.
The authors of the study stress that this discovery underscores a critical link: on-farm antibiotic use directly impacts public health risks. They urge urgent action to address two key issues:
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Antibiotic Stewardship: Implementing stricter controls and guidelines regarding the use of antibiotics in livestock farming is essential to slow down the development and spread of multidrug-resistant bacteria.
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Improved Hygiene Practices: Stricter sanitation measures throughout the dairy production chain are crucial for preventing bacterial contamination from the start, minimizing the reliance on antibiotics as a primary control method.
Without these changes, the widespread consumption of raw milk carries an increasingly dangerous risk: a growing reservoir of antibiotic-resistant bacteria capable of jeopardizing human health.
