Analysis Of Intra - Articular Bacterial Community In Patients With Osteoarthritis

Objective To analyze the distribution of bacterial communities in the joint of patients with osteoarthritis (OA) through the technology based on 16S rDNA clone library. To explore the role of bacteria in the pathogenesis of OA.Methods 26 patients with osteoarthritis underwent joint replacement surgery or arthroscopic surgery in our PUMCH were selected and divided into severe group (n=20) and mild group (n=6) by the severity of the disease Haematological inflammatory markers and inflammatory factors levels of synovial fluid were compared between the two groups. After the extraction of DNA of the synovial fluid samples collected during operation, a 1400bp fragment 16S rDNA gene was amplified by polymerase chain reaction (PCR), the gene fragment library of which was constructed and sequened. The result of the sequence was compared to the genome data base of NCBI to identify to corresponding bateria. Combined with the T-RFLP method, the distribution of bacterial communities in each sample was determined. The differences in bacterial communities between the two groups were compared by principal component analysis.Results No significant difference was shown in the level of ESR, hsCRP and MMP-9 between the two groups. The level of TNF-α and IL-1β were significantly higher in the severe group than in the mild group (P<0.05). The bacterial 16S rDNA target fragment was detected in all of the samples after PCR amplification. A total of 25 kinds of bacterial sequences could match with existing database sequences, of which the most abundant of the three bacteria are Aquabacterium fontiphilum strain, Acinetobacter and Propionibacterium acnes. The principal component analysis showed that bacterial communities between the two groups are different; there were more Propionibacterium acnes, Alcanivorax sp., Aggregatibacter aphrophilus strain, and Alpha proteobacterium in the severe group.whereas Achromobacter xylosoxidans strain and Caulobacter sp. are the main bacteria in the mild group.Conclusion Aquabacterium fontiphilum strain, Acinetobacter and Propionibacterium acnes and other bacteria may be present in the joints of patients with OA. These bacteria may be involved in the development of OA, especially during the sudden aggravation of symptoms or chronic persistent period of the disease.