Indirect enzyme-linked immunosorbent assay method based on Streptococcus agalactiae rSip-Pgk-FbsA fusion protein for detection of bovine mastitis.

OBJECTIVE: The aim of this study was to establish a rapid and accurate method for the detection of the Streptococcus agalactiae antibody (SA-Ab) to determine the presence of the bovine mastitis (BM)-causative pathogen. METHODS: The multi-subunit fusion protein rSip-Pgk-FbsA was prokaryotically expressed and purified. The triple activities of the membrane surface-associated proteins Sip, phosphoglycerate kinase (Pgk), and fibronectin (FbsA) were used as the diagnostic antigens to establish an indirect enzyme-linked immunosorbent assay (ELISA) method for the detection of SA-Ab in BM. RESULTS: The optimal antigen coating concentration was 2 µg/mL, the optimal serum dilution was 1:160, and the optimal dilution of the enzyme-labeled secondary antibody was 1:6000. The sensitivity, specificity, and repeatability tests showed that the method established in this study had no cross-reaction with antibodies to Streptococcus pyogenes, Escherichia coli, Staphylococcus aureus, and Staphylococcus epidermidis in the sera. The results of the sensitivity test showed that a positive result could be obtained even if the serum dilution reached 1:12,800, indicating the high sensitivity and good repeatability of the method. The positive coincidence rate of this method was 98.6%, which is higher than that of previous tests established with the Sip or Pgk mono-antigen fusion protein, respectively, demonstrating the relatively higher sensitivity of this newly established method. The detection rate for 389 clinical samples was 46.53%. CONCLUSIONS: The indirect ELISA method established in this study could provide a more accurate and reliable serological method for the rapid detection of S. agalactiae in cases of BM.

Comparative analysis of allogeneic bone pad and autogenous bone graft in anterior cervical interbody fusion / 中国组织工程研究

BACKGROUND:Surgical treatment is often required for fractures of the cervical vertebrae. Anterior interbody fusion technology is stil the main method for the treatment of cervical degeneration or traumatic instability. Here, the self-made oval al ogeneic bone pad can adapt to different height and width of the intervertebral space, in line with the physiological shape of the intervertebral space. OBJECTIVE:By comparison with autogenous iliac crest bone, to evaluate various types of self-designed al ogeneic bone pads on anterior cervical interbody fusion. METHODS:From January 2009 to December 2013, 58 patients with cervical disc herniation were enrol ed and subjected to cervical discectomy and anterior cervical interbody fusion. According to different bone grafts, these patients were divided into al ogeneic bone pad and autogenous iliac bone groups. The course of disease was 12 to 24 months. The postoperative effect was measured by Japanese Orthopaedic Association (JOA) score, cervical fusion rate, fusion time, operative time, blood loss and rejection rate. RESULTS AND CONCLUSION:At 6 months postoperatively, the JOA score of two groups had no significant difference at 6 months after treatment (P>0.05);the cervical fusion rates were 83.7%and 87.8%, respectively, in the al ogeneic bone pad and autogenous iliac bone groups, with no significant difference (P>0.05). Fusion time was higher in the al ogeneic bone pad than in the autogenous iliac bone group (P<0.05). The internal fixators in the two groups were firmed without loosening, and there was no rejection during the fol ow-up. Compared with the autogenous iliac crest bone, anterior cervical interbody fusion with al ogeneic bone pad can achieve satisfactory effects, which can be better for intervertebral fusion and cannot induce pain due to bone cutting.