Dunn CM, Velasco C, Rivas A, et al. - In the present study, the researchers sought to describe the microbial DNA profile of articular cartilage and determine changes correlated with OA. From knee and hip OA patients and cadaveric controls, 16s rRNA gene deep sequencing was conducted on eroded and intact cartilage samples. The investigation shows a microbial DNA signature in the cartilage of humans and mice. During the development and progression of human OA, alterations were noted in this signature, including rises in Gram-negative constituents. In addition, strain-specific signatures within mouse cartilage that mirror human patterns were identified. Functional analysis showed increases in lipopolysaccharide production, phosphatidylinositol signaling, and nitrogen metabolism and declines in sphingolipid metabolism related to OA. The establishment of these DNA signatures and their possible pathogenic role require further research.