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Objective To analyze the genotypes and homology of MSP?1 and CSP gene of Plasmodium vivax in Shandong Province,so as to provide the evidence for case traceability. Methods A total of 12 blood samples were collected from P. vivax?infected cases in Shandong Province in 2011. Parasite genomic DNA was extracted. Primers were designed according to MSP?1 and CSP gene sequences of P. vivax. Then Nested PCR,enzyme digestion,sequencing and sequence alignment,and homolo?gous analysis were performed. Results The MSP?1 gene of all the 12 samples from P. vivax?infected cases were detected with a 470 bp PCR amplification band,and 350 bp and 120 bp enzyme digestion fragments,which were identified as type Sal?1. An analysis of phylogenetic tree of MSP?1 gene showed that the sequences of 9 indigenous case samples in Shandong Province were located in the same branch,one case sample infected from India was located in the same branch with India strains. All the 12 P. vivax?infected samples covered GDRA(D/A)GQPA sequences in CSP gene,which were identified as type PV?Ⅰ. Of the CSP gene among 12 P. vivax?infected samples,10 samples of indigenous case in Shandong Province and one sample of the case in?fected in Guangdong Province were detected with both 560-840 bp and 150-230 bp PCR amplification bands,which were iden?tified as temperate zone family strain of type PV?Ⅰ. However,one sample from the case infected in India was detected only with a 560-840 bp band,which was identified as tropical zone family strain of PV?Ⅰ. An analysis of phylogenetic tree of CSP gene showed that the sequences of 10 samples from the indigenous cases in Shandong Province and one sample from the case infected in Guangdong Province were located in the same branch,one sample from the case infected in India was located in the same branch with India and Indonesia strains. Conclusion Of all the indigenous isolates in Shandong Province,MSP?1 gene is geno?typed type Sal?1,CSP gene is genotyped temperate zone family strain of type PV?Ⅰ,with a high homology found among the in?digenous isolates.
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Objective To explore the association between malaria epidemic situation and some natural and social factors in high?incidence areas of Shandong Province,so as to provide evidences for malaria elimination in these areas. Methods Twenty towns of 10 counties(cities,districts,)in the high incidence areas of malaria in Shandong Province were selected as the study sites,and the residents in the study sites were investigated by questionnaires with one household as a unit,so as to understand the related natural and social factors. In addition,the malaria epidemic data in the study sites from 2006 to 2010 were collected, and the correlation between these factors and the epidemic situation of malaria was analyzed by Spearman rank correlation and multiple stepwise regression. Results The square root of malaria incidence rate(Y)was negatively related to the rate of house?holds using insecticide(X3),and the rate of households using screen doors and windows(X4)(both P<0.05),but was positive?ly related to the rate of housing surrounding water environment and exposure ratio(X6)(both P<0.05). The regression equa?tion established was Y=0.032X5+0.048X6-0.495,R2=0.973. Conclusions Malaria incidence is obviously associated with some natural and social factors. The measures such as clearing the breeding place of mosquito,protecting the exposure popula?tion at nightfall,as well as using door?window screen and repellents correctly,can effectively control malaria.
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Objective To subclone express and identify the immune mapped protein 1 IMP1 which encodes a surface an?tigen of Toxoplasma gondii. Methods The cDNA of T. gondii RH strain was synthesized by reverse transcription PCR the IMP1 open reading frame ORF was amplified by PCR using the T. gondii RH strain cDNA as template the PCR products were identified by TA?cloning and sequencing then the IMP1 ORF was subcloned into the NdeⅠand Xho I sites of the vector pET28b and the positive recombinant pET28b?IMP1 was identified by double?digesting and sequencing. The protein of 6 × His tagged IMP1 was inducibly expressed in E. coli strain BL21 DE3 with isopropylβ?D?1?thiogalactopyranoside IPTG and the induction time concentration of IPTG and temperature gradients to optimize protein expression conditions were determined. After the cells carried IMP1 were induced by the optimized conditions and harvested the resulting bacteria were suspended in resuspension buffer and lysed by sonication and the supernatants were loaded onto the Ni2+Chelating Sepharose Fast Flow col?umn for affinity chromatography of the N?terminal 6 × His tagged IMP1 protein. Finally the fusion IMP1 proteins were identified by Western blotting. Results The ORF sequence of IMP1 was successfully subcloned from the cDNA of Toxoplasma Gondii RH strain and the amplified product was sequenced and identified based on which the IMP1 ORF gene was inserted into the prokaryotic expression vector pET28b and the recombinant pET28b?IMP1 was constructed successfully. The double?digesting and sequencing results indicated the validity of the recombinant vector. And the optimized conditions for the expression of IMP 1 was determined namely 0.3 mmol/L IPTG induction for 9 h at 20℃. Furthermore IMP1 protein was expressed solubly and che?lated on Ni2+sepharose beads with high affinity thus this protein could be purified efficiently by affinity chromatography. The pure fusion protein was confirmed with fine immunocompetence by SDS?PAGE and Western blotting. Conclusions IMP1 pro? tein can be high efficiently expressed by the E. coli prokaryotic expression systems the protein of IMP1 is soluble and has stable characters. The study may lay a useful foundation for the following works including in vivo expression of IMP1 crystal structure study of IMP1 and anti?toxoplasmosis subunit vaccine development.
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Objective To construct a multi-gene recombinant pcDNA3-HBsAg-p30-ROP2 expression vector and identify it preliminarily. Methods According to recombinant pcDNA3-p30-ROP2 restriction sites,HBV HBsAg gene sequences of primers were designed and synthesized to amplify target fragment,and then cloned into pcDNA3-HbsAg-p30-ROP2 expression vector. Af-ter sequencing,it was identified finally by restriction enzyme digestion and other molecular biology techniques. Results HBV HBsAg gene segment was amplified by PCR and the multi-gene recombinant pcDNA3-HBsAg-p30-ROP2 expression vector was constructed and identified to be correct as theoretical values. The PCR and restriction enzyme digestion results showed that HBsAg and p30-ROP2 gene in recombinant plasmid were confirmed by DNA sequencing. Conclusion The multi-gene recombinant pcD-NA3-HBsAg-p30-ROP2 expression vector is successfully constructed.
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To understand the possibility of schistosomiasis transmission on the East Route Project of the South-to-North Water Diversion Project, a survey of endemic status of schistosomiasis in Weishan Lake area was conducted. A cluster sampling of 2086 boatmen were screened with DDIA Kit, and the positive ones were examined with Kato-Katz technique. Meanwhile, a questionnaire survey about schistosomiasis control was carried out to collect the data about the boatmen's general information and knowledge , attitude and practice (KAP). The results showed there were no schistosomiasis patients. However, there exist potential risk factors for schistosomiasis transmission because of the bad hygiene habits and the poor knowledge of schistosomiasis prevention in boatmen.
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To obtain the functional fusion protein of rhoptry protein 2, compound rhoptry protein2 and surface antigen 1 of Toxoplasma gondii. the ROP2 and P30 genes from genomic DNA of T.gondii RH strain were amplified by PCR, and were inserted into pMD18-T cloning vector. Then the ROP2 fragment was subcloned to pET-30a(+) plasmid digested by EcoRⅠand Hind Ⅲ to construct plasmid pET-ROP2. Furthermore,the P30 fragment was subcloned into pET-ROP2 digested by BglⅡand EcoRⅠto create plasmid pET-ROP2-P30, the resulting recombinant plasmids , transformed into E.coli BL21 (DE3), were induced with IPTG. and the proteins identified by SDS-PAGE were further purified and refolded. The biological activity was analyzed by Western blot with specific antibody. It was found that the sizes of ROP2 and ROP2-P30 were 1212 and 1896bp with corresponding molecular weight 50- kDa and 75-kDa, respectively. The recombinant protein ROP2 (50-kDa) could specifically react with rabbit-polyclonal antiserum, and complex fusion protein ROP2-P30 (75- kDa) could react with P30 monoclonal antibody.
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To provide the basis for preparation of diagnostic kits and vaccines in Toxoplasma gondii infection, the gene coding for the qualified recombinant p30 protein (SAG1) of this parasite was amplified by PCR, and the amplified gene was cloned into prokaryotic expression vector pET-30a(+) to construct the recombinant plasmid, and then transformed to E.coli DH5α. The positive recombinant plasmid was screened by PCR and double enzymes digestion, and the nucleotide sequence of p30 gene was determined by automated DNA sequencing. Meanwhile, the identified recombinant plasmid was transformed to E.coli BL21(DE3) with the expression of p30 on bacteria induced by IPTG and the expressed protein was identified by SDS-PAGE. The protein obtained was then further purified and refolded, and its biological activity was checked by Western blotting. It was shown that the size of the amplified gene was 750 bp with molecular weight of 30 ku, and this protein could specifically react with monoclonal antibody against p30 protein.
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Objective To study the protective effect of ROP2 nuclei acid vaccine in mice.Methods Forty-two BALB/c mice were divided into three groups.Each mouse in experiment group was injected with 50 ?g recombinant plasmid pc-DNA3-ROP2 through musculus quadriceps fexoris.In control groups,each mouse was injected with 50 ?g blank plasmid pc-DNA3 and with 50 ?l PBS respectively.All mice were immunized for three times with an interval of three weeks.The volume was doubled for the final injection in the two plasmid groups.Blood,spleens and lymph nodes of 4 mice in each group were taken for the detection of CD4+,CD8+ T cells and cytokines 2 weeks after the final immunization.The rest mice in 3 groups were challenged with 500 tachyzoites of Toxoplasm gondii RH strain for further observation.Results The vaccine induced strong cellular and humoral immune response.The titer of antibody in serum was high after inoculation and recognized ROP2 protein antigen expressed in vitro.The lymphocyte phenotype was analyzed.CD4+ T cells proliferated sharply(69.5?3.4)%,and the ratio of CD4+/CD8+ increased considerably by(4.69?1.32)%(P