假体周围高糖环境对葡萄球菌感染影响的实验研究

目的 探讨假体周围高糖环境对葡萄球菌生长和细菌生物膜形成的影响.方法 利用新西兰大白兔建立假体感染的动物模型,分为金黄色葡萄球菌组(金葡菌组,n=40)和表皮葡萄球菌组(表葡菌组,n=60),每组再随机分为实验组和对照组,实验组注入细菌的同时加入0.1ml质量浓度为1%的葡萄糖溶液,对照组加入0.1 ml生理盐水.金葡菌组分别于第2、4、6和8天观察;表葡菌组分别于2、4、6、8、12和16天观察.对不同时间点的膝关节假体感染动物行细菌计数、扫描电镜和组织学观察.结果 金葡菌组第2天实验组和对照组关节液细菌计数差异无统计学意义(P=0.426),注入细菌后第4、6和8天实验组较对照组细菌生长明显增强,差异均有统计学意义(P<0.05).扫描电镜观察第2、4、6天实验组较对照组假体表面黏附细菌明显增多(P<0.05),细菌生物膜生成明显.组织学观察第2天实验组假体周围组织发现细菌,而对照组未发现细菌.表葡菌组第2、4、6、8、12和16天实验组与对照组细菌计数差异均无统计学意义(P>0.05),假体表面黏附细菌没有明显区别(P>0.05).组织学观察第2天实验组和对照组假体周围组织均未发现细菌.结论 假体周围高糖环境对金葡菌感染影响明显,而对表葡菌感染影响不明显.

An experimental study: the effect of Periprosthetic high glucose environmental condition on Staphylococcus infection

Objective To evaluate the effect of periprosthetic high glucose environment on the growth of Staphylococcus and bacterial biofilm formation. Methods New Zealand white rabbits were used to establish the animal model of prosthetic infection. There were staphylococcus aureus group (SA, n=40) and Staphylococcus epidermidis group (SE, n=60). Each group were randomly divided into the experimental group and control group. The bacteria were injected with 0.1ml l%glucose into the knee of rabbits in experi-mental group; the rabbits were injected with 0.1ml normal saline in the control group. The SA group were observed in the 2,4,6 and 8 days; The SE group were observed at 2,4,6,8,12 and 16 days. Bacterial counts, scanning electron microscopy and histological observations were used to the changes. Results In the SA group, there was no difference in bacteria counts of synovial fluid between the experimental group and control group 2 days after injection (P=0.426). But 4,6 and 8 days after injection ,the bacteria counts of synovial fluid in the experimental group increased significantly. Scanning electron microscopy found On the day of 2,4,6, the number of bacteria adhere to the prosthetic surface had increased significantly in experi-mental group, compared with the control group.The bacterial biofilm formed significantly. Histological exami-nation revealed that the bacteria were found in the tissue surrounding prosthesis two days after injection,but not in the control group. In SE Group no difference was found in bacterial counts of synovial fluid between the experimental group and control group after 2,4,6,8,12 and 16 days after injection,as well as the num-ber of bacteria adhere to the prosthetic surface Histological examination revealed that no bacteria was found in the tissues around prosthesis in two groups. Conclusion High glucose environment has significant effect on prosthetic infection by Staphylococcus aureus, but not those caused by Staphylococcus epidermidis.