假体周围感染兔模型中D-二聚体的动态表达与感染时间和种植细菌量的相关性研究

Study on the Correlation between the Dynamic Expression of D-Dimer and the Infection Time and the Amount of Bacteria Planted in the Rabbit Model of Prosthesis Infection

目的:研究D-二聚体的表达水平在假体周围感染(Prosthetic Joint Infections,PJI)兔模型中与细菌感染时间和种植菌量的相关性。方法:用金黄色葡萄球菌(Methicillin-Resistant Staphylococcus Aureus,MSSA)建立PJI大白兔模型,分别以0 cfu/mL(仅注射生理盐水,MSSA-A组)、0.5×10^(4) cfu/mL(MSSA-B组)、0.5×10^(5) cfu/mL(MSSA-C组)、0.5×10^(6) cfu/mL(MSSA-D组)的MSSA进行感染,每组各10只。扫描电镜(Scanning Electron Microscope,SEM)观察细菌生物膜形成。试剂盒法检测PJI术前及术后1,7,13 d各组血液中的C反应蛋白(C-Reactive Protein,CRP)、血沉(Erythrocyte Sedimentation Rate,ESR)及D-二聚体的浓度变化。分析D-二聚体的动态表达与感染时间和细菌浓度之间的相关性。结果:术后13 d各组关节腔液标本中的细菌类型与接种菌一致,均为MSSA。与MSSA-A组比,术后1,7,13 d的MSSA-B组、MSSA-C组、MSSA-D组中的C反应蛋白(F=215.369,189.115,155.698;P=1.153×10^(-6),2.559×10^(-5),3.662×10^(-6))、血沉(F=170.691,206.445,181.229;P=8.169×10^(-5),6.182×10^(-6),5.177×10^(-5))、D-二聚体(F=155.600,189.662,89.710;P=1.821×10^(-4),5.299×10^(-5),4.058×10^(-4))均持续增加,13 d的假体周围细菌阳性率也增加,差异均有统计学意义(F=214.366,P=6.125×10^(-5))。另外,术后1,7,13 d D-二聚体的表达水平与细菌浓度都正相关(P=0.003,0.002,0.001;r=0.921,0.955,0.923)。结论:PJI兔模型中13 d内D-二聚体的表达随时间增加而增加,D-二聚体的动态表达与种植细菌量正相关。

Objective:To study the correlation between the dynamic expression of D-dimer and the infection time and the amount of bacteria planted in the rabbit model of prosthesis joint infection.Methods:Staphylococcus aureus(MSSA)was used to establish a PJI white rabbit model.Rabbits were infected with 0 cfu/mL(injection of saline only,MSSA-A group),0.5×10^(4)cfu/mL(MSSA-B group),0.5×10^(5)cfu/mL(MSSA-C group),0.5×10^(6)cfu/mL(MSSA-D group)respectively,n=10.Scanning electron microscope(SEM)was used to observe the formation of bacterial biofilm.The kit method was used to detect the concentration changes of C-reactive protein(CRP),erythrocyte sedimentation rate(ESR)and D-dimer in the blood of each group before PJI and 1 d,7 d and 13 d after PJI operation.The correlation between the dynamic expression of D-dimer and the infection time and bacterial concentration was analyzed.Results:13 d after operation,the types of bacteria in the joint cavity fluid samples of each group were consistent with the inoculated bacteria,and they were all MSSA.Compared with MSSA-A group,the CRP of MSSA-B group,MSSA-C group and MSSA-D group at 1,7 and 13 d after surgery(F=215.369,189.115,155.698;P=1.153×10^(-6),2.559×10^(-5),3.662×10^(-6)),ESR(F=170.691,206.445,181.229;P=8.169×10^(-5),6.182×10^(-6),5.177×10^(-5)),D-dimer(F=155.600,189.662,89.710;P=1.821×10^(-4),5.299×10^(-5),4.058×10^(-4)),and the positive rate of bacteria around the prosthesis at 13 d also were increased,and the differences were statistically significant(F=214.366,P=6.125×10^(-5)).In addition,the expression level of D-dimer was positively correlated with the bacterial concentration at 1 d,7 d and 13 d postoperatively(P=0.003,0.002,0.001;r=0.921,0.955,0.923).Conclusion:The dynamic expression of D-dimer in the PJI rabbit model is positively correlated with the infection time and the number of bacteria grown.