Occurrence of pS86/pEF47-related plasmids in gram-positive cocci

Area of Science:

• Microbiology
• Plasmid Biology
• Bacterial Genetics

Background:

• Enterococcus faecalis is a common bacterium found in various environments, including the rumen.
• Plasmids are extrachromosomal DNA elements that can confer advantageous traits to bacteria.
• Cryptic plasmids, whose functions are not immediately apparent, are frequently found in bacterial populations.

Purpose of the Study:

• To isolate and characterize a cryptic plasmid from a rumen bacterium.
• To investigate the relationship between plasmids from different bacterial sources (rumen vs. human clinical).
• To determine the prevalence of pS86/pEF47-related replicons in gram-positive cocci.

Main Methods:

• Isolation and partial characterization of the plasmid pEF47 from Enterococcus faecalis 47.
• Restriction enzyme analysis and partial DNA sequencing of pEF47.
• Polymerase Chain Reaction (PCR) and Southern hybridization techniques.

Main Results:

• A 5.5-kb cryptic plasmid, pEF47, was successfully isolated from rumen Enterococcus faecalis.
• pEF47 showed high homology to the pS86 plasmid from a human clinical isolate of Enterococcus faecalis.
• PCR and Southern hybridization confirmed the widespread presence of pS86/pEF47-related replicons in plasmids from gram-positive cocci.

Conclusions:

• The study identified and characterized a novel plasmid, pEF47, from a rumen bacterium.
• The findings highlight significant genetic similarity between plasmids found in distinct Enterococcus faecalis populations.
• The research indicates that pS86/pEF47-type replicons are common among plasmids of gram-positive cocci, suggesting horizontal gene transfer or shared ancestry.