ABSTRACT
Objective To evaluate the immunoprotection by the inactivated whole bacteria(IWB) of Stenotrophomonas maltophilia K279a in mice.Methods Mice were immunized by inactivated whole bacteria of S.maltophilia K279a made from formaldehyde.When the indicated the antibody titer of the mice reached the require level, the protective effect of the IWB was evaluated by performing the opsonophagocytic killing test in vitro and the poison attack experiments in vivo. Results It was found that IgG in serum of the immunized mice measured by ELISA was significantly increased after the second immune enhancement, and antiserum in vitro had strong phagocytic effect.Meanwhile, immunoprotection of the immunized groups was also significantly increased when challenged by S.maltophilia K279a.Conclusion Effective humoral immune response can be predominantly induced by the inactivated whole bacteria of S.maltophilia K279a, providing protection against challenge by S.maltophilia K279a in BALB/c mice.
ABSTRACT
Objective To explore the interaction of streptococcus suis serotype 2 recombinant suilysin ( SLY ) with platelets, and provide the theoretical basis for clinic treatment of patients infected with S.suis.Methods The nickel column affinity chromatography was used to purify the recombinant SLY.The hemolytic acivity was identified by optical density before the platelets aggregation induced by a SLY was detected by a platelet aggregometer or electron microscope and the effect of aspirin on platelets aggregation was analyzed.The impact of wild type 05ZYH33 and sly-deficient mutant strainΔSLY on platelets of mice was compared to predict the interaction of the SLY with platelets in vivo.Results and Conclusion Hemolytic activity of recombinant SLY was 2000 hemolytic units( HU) and platelets aggregation was induced at 1 μg/ml.The aggregation can be inhibited by aspirin in 5 mmol/L.SLY can also increase the volume and reduce the amount of platelets in mice.