The Reseach On The Effect Of Epidermis Staphylococcus AgrC Specific-binding Polypeptide On Bacterial Biofilm Formation On The Surface Of Polyvinyl Chloride

Objective: To research the effect of epidermis staphylococcus agrC specific-binding polypeptide on bacterial biofilm formation on the surface of polyvinyl chloride. To lay the foundation for the synthesis of agrC as a target-specific drug which can treat biofilm formation by staphylococcus epidermidis related infection.Methods:1.Using microplate semi-quantitative method to determine optimum antibacterial concentration of agrC specific-binding polypeptide.2.Using microplate semi-quantitative method to observe effects of agrC specific-binding polypeptide on biofim formation ability of Staphylococcus epidermidis at different growth times.3.Using scanning electron microscopy to detect the surface structure of bacterial biofilm on the surface of PVC material.4.Using laser scanning confocal microscope to detect the number of bacterial communities, the thickness of bacterial biofilm formation and the three-dimensional structure of bacterial biofilm on the surface of PVC material.Results:1.Microplate semi-quantitative method results showed that optimum antibacterial concentration of agrC specific-binding polypeptide was 800 ?g/ml.2.Microplate semi-quantitative method results showed that when the concentration of agrC specific-binding polypeptide was 800 ?g/ml ,it had inhibitory effect on the formation of bacterial biofilm at 12 hours.3. Scanning electron microscopy showed that the experimental and control groups were scattered in small bacterial clumps when the epidermal staphylococcus ATCC35984 was cultured at 6h. When the bacterial was cultured at 12h, small bacterial clumps of the experimental group was significantly less than the control group. At 18h, both groups were able to see clusters of bacteria that were connected to each other in the form of sheets and towers. At 24h, both groups were shown mature biofilm structures,which were filled with a large number of amorphous extracellular matrix. At 30h, two groups of the biofilm structure were visible, but some of them were disassembled. Epidermal staphylococcus ATCC12228 biofilm was not formed in the experimental group and the control group at 6, 12, 18, 24 and 30h.4. Laser scanning confocal microscope showed that agrC-specific binding peptide was added to the experimental group and unrelated peptide was added to the control group,during the incubation period of 12h, the bacteria on the surface of PVC in the experimental group was significantly less than that in the control group,and in the majority with dead bacteria. At 6, 18, 24 h, the two groups of bacteria did not see any significant difference, and they were mostly living bacteria. The thickness of bacterial biofilm was significantly lower than that of control group at 12 h after incubation, and there was no significant difference in biofilm thickness at other time points.Conclusion:1. There is a dose-effect relationship between the bacteriostatic intensity of Staphylococcus aureus and agrC-specific binding polypeptides.2.AgrC-specific binding polypeptide has a significant inhibitory effect on the formation of Staphylococcus epidermidis biofilm in the aggregation stage of biofilm formation: agrC specific binding polypeptide can inhibit the ability of the formation of Staphylococcus epidermidis biofilm; agrC-specific binding polypeptides can prevent staphylococcus epidermidis from accumulating further, allow bacterial agglomerates to loose and prevent biofilm formation; agrC-specific binding polypeptides can inhibit bacterial proliferation in the aggregation phase of bacterial biofilm formation,accelerate bacterial death, and affect the thickness of bacterial biofilm formation.3.AgrC-specific binding peptides can lay the foundation for specific drugs for the treatment of epidermal staphylococcal biofilm-related infections. It may be more effective as' a prophylactic agent, and the inhibitory effect on mature biofilm is not obvious.