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ObjectiveTo investigate the drug-resistant gene polymorphisms in Plasmodium falciparum imported from Equatorial Guinea to Shandong Province. MethodsFrom 2015 to 2016, blood samples were collected from imported P. falciparum malaria patients returning from Equatorial Guinea to Shandong Province, and genome DNA of the malaria parasite was extracted. The drug-resistant Pfcrt, Pfmdr1, Pfdhfr, Pfdhps, and K13 genes of P. falciparum were amplified using a PCR assay, followed by DNA sequencing, and the sequences were aligned. Results The target fragments of all 5 drug-resistant genes of P. falciparum were successfully amplified and sequenced. There were 72.8%, 18.6%, and 8.6% of P. falciparum parasites carrying the wild-, mutant-, and mixed-type Pfcrt gene, respectively, and all mutant haplotypes were CVIET (the underline indicates the mutation site). There were 20.0%, 61.4% and 18.6% of P. falciparum parasites carrying the wild-, mutant-, and mixed-type Pfmdr1 gene, respectively, and the mutant haplotypes mainly included YF and NF (the underlines indicate the mutation sites). There were 1.4%, 98.6%, and 0 of P. falciparum parasites carrying the wild-, mutant-, and mixed-type Pfdhfr gene, respectively, and AIRNI was the predominant mutant haplotype (the underline indicates the mutation site). There were 1.4%, 94.3%, and 4.3% of P. falciparum parasites carrying the wild-, mutant-, and mixed-type Pfdhps gene, respectively, and SGKAA was the predominant mutant haplotype (the underline indicates the mutation site). The complete drug-resistant IRNGE genotype consisted of 8.6% of the Pfdhfr and Pfdhps genes, and the K13 gene A578S mutation occurred in 1.4% of the parasite samples. Conclusions There are mutations in the Pfcrt, Pfmdr1, Pfdhfr, Pfdhps, and K13 genes of P. falciparum imported from Equatorial Guinea to Shandong Province, with a low frequency in the Pfcrt gene mutation and a high frequency in the Pfmdr1, Pfdhfr, and Pfdhps gene mutations, and the K13 gene A578S mutation is detected in the parasite samples.
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To prepare and purify the rabbit anti-TgMIC16 polyclonal antibody, so as to apply it in subcellular localization.New Zealand white rabbits were immunized with purified recombinant TgMIC16 mixing with the same volume of Freund’s adjuvant for three times, respectively. The rabbit serum was collected on the 14th day after the last immunization. The polyclonal antibody in rabbit serum was purified with Protein A affinity purification column. ELISA and Western blotting were used to detect the antibody titer and specificity of polyclonal antibody. The polyclonal antibody was used to the localization of TgMIC16 by the immunofluorescence method.Indirect ELISA showed that the antibody titer was 1∶512 000. Western blotting showed that the recombinant TgMIC16 protein was recognized by the specific polyclonal antibody. IFA showed that TgMIC16 was located in the microneme of Toxoplasma gondii.The rabbit anti-TgMIC16 is prepared and purified, and successfully applied to immunofluorescence localization of TgMIC16 in T. gondii.
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Objective To construct pEGFP-N1-HBsAg-ROP2 recombinant expression plasmid and transfect HEK293T cells for expression,and pay a way for Toxoplasma gondii nucleic acid vaccine development. Methods According to the HBsAg gene sequence and pcDNA3-p30-ROP2 recombinant plasmid restriction sites,the HBsAg gene was amplified by PCR.The HB-sAg gene was cloned into the pcDNA3-p30-ROP2 and instead of p30 gene.The HBsAg-ROP2 fragment was amplified by PCR and digested with HindⅢand KpnⅠto clone into the pEGFP-N1 eukaryotic expression vector and construct the recombinant pEGFP-N1-HBsAg-ROP2.The expression vector was transfected into HEK293T cells based on the identification of PCR amplifi-cation,restriction endonucleases and sequencing.Results The PCR product of HBsAg was about 700 bp,which was consis-tent with the theoretical value.Two bands of about 5.4 kb and 1.9 kb were obtained after double enzyme digestion with pcDNA3-HBsAg-ROP2 recombinant plasmid.The recombinant plasmid pEGFP-N1-HBsAg-ROP2 was double-digested to generate an empty vector fragment of about 4.7 kb and a band of about 1.9 kb of HBsAg-ROP2 fragment.The results of sequencing showed that the sequence was 99.84% identical with the published sequence in GenBank.The target plasmid was successfully transfect-ed into HEK293T cells,and the expression was correct,the protein concentration was 3.08 mg/ml.Conclusion The recombi-nant plasmid pEGFP-N1-HBsAg-ROP2 is successfully constructed and expressed efficiently.
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At present,there are no ideal drugs and measures in the treatment and prevention of toxoplasmosis.The develop-ment of safe,convenient,and strong protective nucleic acid vaccine is an important strategy for prevention and control of toxo-plasmosis.The rhoptry protein(ROP)is a large class of proteins secreted by Toxoplasma gondii.ROPs play an important role in the invasion of host cells,the formation of parsitophorous vacuole(PV)and the regulation of proliferation by T.gondii.Thus, ROPs become the most promising candidates of vaccine.In this paper,we summarize the important members of the ROPs,the expression vector and the immunogenicity and immunoprotection of the nucleic acid vaccine in animal experiments.
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Malaria remains a serious public health problem in Shandong Province, China; therefore, it is important to explore the characteristics of the current malaria prevalence situation in the province. In this study, data of malaria cases reported in Shandong during 2012-2014 were analyzed, and Plasmodium species were confirmed by smear microscopy and nested-PCR. A total of 374 malaria cases were reported, 80.8% of which were reported from 6 prefectures. Of all cases, P. falciparum was dominant (81.3%), followed by P. vivax (11.8%); P. ovale and P. malariae together accounted for 6.4% of cases. Notably, for the first time since 2012, no indigenous case had been reported in Shandong Province, a situation that continued through 2014. Total 95.2% of cases were imported from Africa. The ratio of male/female was 92.5:1, and 96.8% of cases occurred in people 20-54 years of age. Farmers or laborers represented 77.5% of cases. No significant trends of monthly pattern were found in the reported cases. All patients were in good condition after treatment, except for 3 who died. These results indicate that imported malaria has increased significantly since 2012 in Shandong Province, especially for P. falciparum, and there is an emergence of species diversity.
Subject(s)
Humans , Africa , China , Farmers , Malaria , Microscopy , Plasmodium falciparum , Plasmodium malariae , Plasmodium ovale , Plasmodium vivax , Plasmodium , Prevalence , Public HealthABSTRACT
Heishui county, located in northwest Sichuan province, southwestern China, is an endemic area of zoonotic visceral leishmaniasis (VL) and is the most intractable area. VL is never destroyed in it. Asymptomatic dogs (Leishmania parasites have been diagnosed but clinically healthy) are considered to be a potential reservoir host in zoonotic VL area, and most can lead to infection of individuals, that is a new challenge for controlling VL in humans. The present study aimed to assess the Leishmania infection rate of asymptomatic dogs in Heishui county. Total 105 asymptomatic domestic dogs were gathered from 4 districts in Heishui county to investigate the infection rate with serological and molecular methods based on ELISA and kinetoplast minicircle DNA(kDNA) PCR, respectively. Out of 105 dogs, 44 (41.9%) were positive by more than 1 method; 21 (20.0%) were positive by ELISA, and 30 (28.6%) were positive by kDNA-PCR. Our study showed that Leishmania infection of domestic dogs which is clinically healthy is prevalent in the studied district, and the asymptomatic dogs infected by Leishmania may be the primary reason for the prevalence of visceral leishmaniasis in the area.