BACKGROUNDTreponema pallidum (T. pallidum) subsp. pallidum is the causative agent of syphilis. Analysis of recombinant antigens of T. pallidum led to the identification of potential candidate antigens for vaccine development and syphilis serodiagnosis. Tp0965 was predicted to be a membrane fusion protein and was found to be reactive with infected human sera in previous studies, but the results were controversial. In this research, the antigenicity and immunoreactivity of recombinant protein Tp0965 were assessed.

METHODST. pallidum subsp. pallidum (Nichols strain) was propagated and isolated and the genomic DNA was extracted. The Tp0965 gene was amplified by polymerase chain reaction (PCR). Then the recombinant protein Tp0965 was expressed in Escherichia coli and purified by nickel-nitrilotriacetic acid (Ni-NTA) purification system. The reactivities of protein Tp0965 were examined by immunoblot analysis and indirect enzyme-linked immunosorbent assay. The antisera against protein Tp0965 were obtained by immune rabbits and the immunogenicity of antisera were detected by indirect enzyme-linked immunosorbent assay.

RESULTSRecombinant protein Tp0965 was expressed successfully in vitro. Immunoblot assay showed that the recombinant protein Tp0965 could be recognized by human syphilitic sera of all stages. Indirect enzyme-linked immunosorbent assay showed there were only 4 of 74 human syphilitic sera that failed to show reactivity to recombinant antigen Tp0965, and lack of reactivity of Tp0965 to all 28 uninfected sera. A low titer of antiserum against Tp0965 in immune rabbits could be detected after the third time of immunization.

CONCLUSIONSThe recombinant antigen Tp0965 shows excellent sensitivity for the reactivity with sera from syphilitic individuals at all stages. The results also demonstrate a potential application for the serodiagnosis of syphilis.

Animals ; Antigens, Bacterial ; genetics ; immunology ; Bacterial Proteins ; genetics ; immunology ; Enzyme-Linked Immunosorbent Assay ; Humans ; Membrane Proteins ; genetics ; immunology ; Polymerase Chain Reaction ; Rabbits ; Syphilis ; immunology ; microbiology ; Treponema pallidum ; immunology ; metabolism

Background Treponema pallidum (T.pallidum) subsp.pallidum is the causative agent of syphilis.Analysis of recombinant antigens of T.pallidum led to the identification of potential candidate antigens for vaccine development and syphilis serodiagnosis.Tp0965 was predicted to be a membrane fusion protein and was found to be reactive with infected human sera in previous studies,but the results were controversial.In this research,the antigenicity and immunoreactivity of recombinant protein Tp0965 were assessed.Methods T.pallidum subsp.pallidum (Nichols strain) was propagated and isolated and the genomic DNA was extracted.The Tp0965 gene was amplified by polymerase chain reaction (PCR).Then the recombinant protein Tp0965 was expressed in Escherichia coli and purified by nickel-nitrilotriacetic acid (Ni-NTA) purification system.The reactivities of protein Tp0965 were examined by immunoblot analysis and indirect enzyme-linked immunosorbent assay.The antisera against protein Tp0965 were obtained by immune rabbits and the immunogenicity of antisera were detected by indirect enzyme-linked immunosorbent assay.Results Recombinant protein Tp0965 was expressed successfully in vitro.Immunoblot assay showed that the recombinant protein Tp0965 could be recognized by human syphilitic sera of all stages.Indirect enzyme-linked immunosorbent assay showed there were only 4 of 74 human syphilitic sera that failed to show reactivity to recombinant antigen Tp0965,and lack of reactivity of Tp0965 to all 28 uninfected sera.A low titer of antiserum against Tp0965 in immune rabbits could be detected after the third time of immunization.Conclusions The recombinant antigen Tp0965 shows excellent sensitivity for the reactivity with sera from syphilitic individuals at all stages.The results also demonstrate a potential application for the serodiagnosis of syphilis.

Objective To retrospectively analyze the research on the integrated medical and elderly care in China in re-cent ten years,and explore the research hotspots and future research trend of the integrated medical and elderly care.Methods Using the method of literature research,the journal articles with the theme of combination of medical care and nursing,integration of medical care and nursing or medical care and nursing service from 2013 to 2023 were searched in CNKI.The sources were lim-ited to Peking University Core,CSSCI,CSCD and AMI,and the selected articles were analyzed by CiteSpace.Results This ar-ticle takes 896 literatures as research objects,we found that the number of articles reached a peak in 2018,the higher number of articles issued by the institutions are medicine-related institutions.The high-frequency keywords are the integrated medical and elderly care,elderly services,senior citizens,elderly care institutions and elderly care model.The strongest emergent word de-tected is health care integration.Conclusion In the past ten years,domestic research on the integration of medical care and eld-erly care has shown diversification and innovation.Policy tools,pension insurance,community and rural pension,quality evalua-tion index system,influencing factors were the research focus of scholars.Future research needs to focus on the application of quantitative methods,empirical and practical analysis.