Plasmidborne

Plasmidborne is an adjective used to describe traits, genes, or phenotypes that are carried on plasmids, the small, circular DNA molecules that replicate independently of the bacterial chromosome. In bacteria and some other microbes, plasmids often encode advantageous functions and can be transferred between cells, making them a major mechanism of horizontal gene transfer.

Many plasmids are conjugative, able to initiate their own transfer to recipient cells; others are mobilizable and require helper elements. Some plasmids are non-transferable but can still influence host biology through carried genes. The repertoire of plasmidborne traits includes antibiotic resistance, virulence factors, metabolic capabilities, and tolerance to heavy metals or other stressors. The spread of plasmidborne resistance genes (often on multidrug resistance plasmids) is a central concern in clinical and environmental settings, particularly under antibiotic selective pressure. Virulence plasmids carry toxins, secretion systems, or adherence factors that enhance a pathogen's ability to cause disease.

Plasmids vary in host range, copy number, and stability, which affects how quickly plasmidborne traits disseminate and persist. Horizontal transfer can occur across species boundaries in many bacterial communities, contributing to rapid adaptation. Researchers study plasmids through sequencing, plasmid profiling, and comparative genomics to understand their evolution and ecology and to monitor the spread of important traits.

Overall, plasmidborne describes the genetic influence of plasmids on organisms and their traits, reflecting an important dimension of microbial evolution and public health.