The emerging role of circulating free bacterial DNA in rheumatoid arthritis

Circulating free bacterial DNA (cfbDNA) refers to small fragments of DNA from bacteria that are present in the blood stream or other bodily fluids. Aim of study is detection of free bacterial DNA in serum of RA patients as predictor for type of bacteria to be related with the RA morbidity. Ninety individuals are included in this study, divided into two primary groups: thirty healthy controls and sixty RA using universal primers and traditional PCR, free bacterial DNA was found in the serum of both patients and controls. Free bacterial DNA was found in eighteen (30%) of the total (60) patient serum with product size (1500 bp) in comparison to thirty negative results in control serum. To identify the bacterial source of the free DNA, the successful binding (band) of the 16s rRNA primer with free bacterial DNA was sequenced and submitted to "BLAST" with "Highly similar sequences" to "16s ribosomal RNA sequences" on NCBI. As a consequence, free bacteria in blood or serum might signal the existence of a bacterial infection even before clinical symptoms occur.