The Effect Of Staphylococcus Epidermidis AgrC Specific Binding Polypeptide On Central Venous Catheterization In Rats

Objective(s):In the previous study,on the basis of agrC specific binding peptide sequence,a rat central venous intubation infection model was established to explore the role of agrC specific peptide in the infection of rats with central venous catheterization,and to clarify the bacterial biofilm on the surface of cardiac surgery biomaterials by agrC specific binding polypeptide.And its role in the implantation of biomaterials.Methods:The rat model of central venous infection was established.Venous blood was taken in different time periods of 0h,6h,1d,2d,3d,5d and 7d respectively.The changes of serum inflammatory cytokines in the rats were detected by flow cytometry.The rats were killed after 7d,and the blood and heart,liver and kidney tissues were observed and compared with the tissue bacteria culture method.The bacterial infection rate and number of bacteria were observed and the infiltration degree of inflammatory cells in blood and heart,liver and kidney tissue was observed by pathological histomorphology HE staining,and the growth of bacteria on the surface of central venous catheter was observed by scanning electron microscope.Objective to investigate the anti infection effect of Staphylococcus epidermidis agrC specific binding peptide on central venous catheterization in rats.Results:The study found that 106 CFU Staphylococcus epidermidis injected into the central venous catheter can successfully replicate the stable rat model of central venous catheter infection.The level of serum inflammatory cytokines in the related peptide N1 group was lower than that of the unrelated peptide NO group(P<0.05);the infection rate of the related peptide N1 group was lower than that of the unrelated peptide N0 group,and the number of bacteria in the blood and heart,liver and kidney decreased(P<0.05).The histopathological results suggested that the correlation peptide N1 group was less invasive than the non peptide N0 group.Under the scanning electron microscope,the thickness and density of the bacterial biofilm in theN1 group were lower than those in the non peptide N0 group.Conclusion(s):The specific binding peptide of Staphylococcus epidermidis agrC can reduce the level of serum inflammatory cytokines in rats with central venous catheterization,weaken the infiltration capacity of inflammatory cells in the infected tissues,weaken the pathogenicity of the infection in the central venous catheterization of rats,inhibit the aggregation of bacteria on the surface of the venous catheter and the formation of the bacterial biofilm.AgrC specific binding peptide may be a new small molecule peptide drug for the treatment of clinically refractory Staphylococcus epidermidis infection.