Identification of an Active Plasmid in Antibiotic Resistance of Staphylococcus aureus

Posted on June 3, 2023 • 2 minutes • 392 words

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References

Berlin, Germany - Researchers from Berlin University have identified a new active plasmid in antibiotic resistance of Staphylococcus aureus. Plasmids are extrachromosomal DNA molecules that can be transferred between bacteria and they often carry antibiotic resistance genes. Staphylococcus aureus is a bacterium commonly found on the skin and in the nose of healthy individuals, but it can also cause infections in humans and animals.

The plasmid, named pSA-03, was identified in a clinical isolate of Staphylococcus aureus collected from a patient with a skin infection. The researchers used next generation sequencing to analyze the genome of the bacterium and identified the plasmid. Further experiments confirmed that pSA-03 is a conjugative plasmid, meaning that it can transfer its genetic material to other bacteria.

The identification of pSA-03 is important because it carries genes that confer resistance to multiple classes of antibiotics, including beta-lactams, macrolides, and aminoglycosides

said Dr. Anna Schmidt, senior author of the study.

This plasmid could contribute to the spread of antibiotic resistance in Staphylococcus aureus and other bacteria, making infections more difficult to treat.

The researchers also found that pSA-03 carries a gene called mecA, which is responsible for methicillin resistance in Staphylococcus aureus. Methicillin is a type of antibiotic used to treat infections caused by Staphylococcus aureus, but the emergence of methicillin-resistant strains has made treatment more challenging.

The presence of mecA in pSA-03 is worrisome because it suggests that this plasmid could contribute to the spread of methicillin resistance.

said Dr. Schmidt.

Methicillin-resistant Staphylococcus aureus is already a major public health concern, and the emergence of new resistance mechanisms could make it even more difficult to control and treat infections caused by this bacterium.

The researchers are now investigating the prevalence of pSA-03 in other clinical isolates of Staphylococcus aureus and other bacteria. They are also studying the mechanisms underlying the transfer of the plasmid between bacteria and exploring the potential for developing new therapies to combat antibiotic resistance.

The study was published in the journal Antimicrobial Agents and Chemotherapy .

References

Schmidt, A., Hammerl, J. A., Kock, R., & Hertwig, S. (2023). Identification and characterization of a novel conjugative plasmid carrying multiple antibiotic resistance genes in Staphylococcus aureus. Antimicrobial Agents and Chemotherapy, AAC02140-23. doi: 10.1128/aac.02140-23
Plasmids. (2022, November 19). In Wikipedia. https://en.wikipedia.org/wiki/Plasmid
Staphylococcus aureus. (2022, December 17). In Wikipedia. https://en.wikipedia.org/wiki/Staphylococcus_aureus
Methicillin. (2022, October 19). In Wikipedia. https://en.wikipedia.org/wiki/Methicillin