ABSTRACT
Objective To establish a mouse model of bacterial vaginosis ( BV) by infecting estro-gen-treated mice with Prevotella bivia ( P. bivia) . Methods The mice were intraperitoneally injected with beta-estradiol 17 valerate which was suspended in sesame oil and then inoculated with different doses of P. bivia strains at the logarithmic phase. Samples of vaginal flushing fluid were collected at different time points after inoculation and used for the isolation of P. bivia strains and the detection of sialidase activities. Altogether 30 mice treated with estrogen and high dose of P. bivia were killed on days 2, 7 and 21 (n=10). Samples of cornua uteri, bladder and kidney were collected from those mice for P. bivia strains isolation. Re-sults Injection the estrogen-treated mice with P. bivia via vagina could cause the P. bivia infection for more than 14 days. The numbers of P. bivia strains isolated on day 21 decreased significantly. Enhanced sialidase activities and clue cells were observed in vaginal secretions of mice with P. bivia infection. Injection of mice with the high dose of P. bivia could spread the infection to cornua uteri. Conclusion Estrogen-treated mice could be used as an animal model for researches on BV.
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Objective To study the role of the outer membrane protein Rmp of Neisseria gonor-rhoeae strain in immunosuppression and the strategy of eliminating it .Methods The rmp gene of Neisseria gonorrhoeae strain was amplified by PCR and inserted into pMD 19-T vector .The recombinant vector pMD 19△rmp∷Kan containing Kan and the 5′-and 3′-flanking regions of rmp (△rmp∷Kan) was constructed by replacing 200 nucleotide residues of pMD 19-rmp with kanamycin resistance gene Kan and transformed into Neisseria gonorrhoeae WHO-A strain.PCR and Western blot assay were used to screen and identify the re-combinant mutant strains that could not express Rmp .Mice were immunized with mutant strains and bacteri-cidal activities of the immune sera were detected by antibody-mediated complement-dependent cytotoxicity assay.Results The mutant strains that could not encode Rmp were successfully constructed .Antibodies in-duced by mutant strains showed stronger bactericidal activity against Neisseria gonorrhoeae in comparison with those induced by wild strains .Conclusion The recombinant Neisseria gonorrhoeae strain with rmp gene de-letion might eliminate the immunosuppressive effects of Rmp expressed in wild gonococcal strains , which provides a reference for further development of novel live attenuated whole-cell vaccines of Neisseria gonor-rhoeae.
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Objective To develop fast detection techniques for the diagnosis of gonococcal infections.Methods Prokaryotic expression vector for Neisserial surface protein A (NspA) was constructed using the NspA gene cloned by PCR.Mice were immunized with the renatured recombinant NspA (rrNspA)to prepare antibodies against NspA.Western blot and ELISA was used to analyze the binding of NspA antibodies to lysate of gonococcal cells or to intact gonococci.Results NspA antibodies that were prepared by the rrNspA expressed in E.coli could bind to rrNspA,the natural NspA existing in gonococcal cells,or intact gonococci.Conclusion RrNspA and its antibodies have potential value in developing fast diagnostic kits for gonococcal diseases.
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The article is to study the status of academic communications,providing useful exploration to enhance the scientific research ability of postgraduate students.In the base of summing up the forms of the internal and external multi-level academic communications,we point out varies of problems existing inall levels.The level and publicity of some academic communications are poor; the postgraduate students' participation is not powerful enough; the guide form supervisors and graduate management are in shortage. These factors are restricting the role of academic communications in training postgraduate's research ability.Therefore,we should take some appropriate improvements.The effect of academic communications in training graduate students' research ability should be enhanced via improvements at various aspects.
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Objective To clone and study the antimicrobial-resistant gene in Neisseria gonorrhoeae.Methods The gene library,which contains the differential genes of antimicrobial resistant strains and stan-dard reference strains of Neisseria gonorrhoeae,was constructed using a technique known as suppression subtractive hybridization(SSH).Then the antimicrobial resistance associated genes were cloned and ana-lyzed.Results Subtractive gene library in antimicrobial-resistant Neisseria gonorrhoeae was successfully constructed,which contains2500positive clones.Sequence analysis was performed on5clones.The se-quences of these five clones were unknown previously.Conclusions The subtractive DNA library is succes-sively constructed which may provide an important clue for studying the mechanism of antimicrobial resis-tance in Neisseria gonorrhoeae.