Antibiotic-resistance genes detected in supermarket produce

A new study from Julius Kühn Institut has confirmed that produce is a source of antibiotic-resistance genes. The researchers have found that produce is a reservoir for transferable resistance traits that often go undetected when using DNA-based screening tools.

According to the Centers for Disease Control and Prevention, antibiotic resistance has now become one of the biggest public health issues worldwide. Every year in the United States, at least two million people fall ill with an antibiotic-resistant infection, and more than 23,000 of them do not survive.

Antibiotic resistance occurs when an antibiotic has lost the ability to control bacterial growth. Once the bacteria have become resistant, they can continue to multiply even when an antibiotic is present.

Resistance to antibiotics can result from a natural progression, as the drugs kill off the more susceptible bacteria, but the resistant strains persist. Today, high levels of antibiotic-resistant bacteria can be attributed to the overuse of antibiotics.

While some bacteria are naturally resistant to certain antibodies, they can also acquire resistance from another bacteria or through a genetic mutation. In addition, viruses can inject antibiotic resistance traits into bacteria.

Bacteria can also obtain “free” DNA from their environment. Any bacteria that acquire resistance genes, whether by genetic exchange with other bacteria or through mutation, are equipped to resist one or more antibiotics.

The current study highlights the significance of the rare microbiome of produce as a source of antimicrobial resistance genes.

Produce is increasingly recognized as a source of pathogenic bacteria, antibiotic-resistant bacteria, and antibiotic resistance genes. The experts set out to characterize the collection of antibiotic resistance genes present in bacteria, or the resistome, associated with produce.

Using cultivation and DNA-based methods, the researchers analyzed mixed salad, arugula, and cilantro purchased from supermarkets in Germany. They identified anti-infection opposition genes in produce that could be transferred to human pathogens and bacteria.

The study also confirmed that the use of cultivation-independent DNA-based screening methods is not a reliable way to detect the transferable resistome in a microbiome such as that found in produce.

The study is published in the journal mBio.

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By Chrissy Sexton, Earth.com Staff Writer