Multiplicity of infection of Plasmodium knowlesi in Malaysia: an application of Pkmsp-1 block IV

@#In Malaysia presently, the main cause of human malaria is by the zoonotic monkey parasite Plasmodium knowlesi. A previous study has suggested that the P. knowlesi merozoite surface protein 1 (Pkmsp-1) block IV to be a suitable multiplicity of infection (MOI) genotyping marker for knowlesimalaria. This study therefore aimed to investigate the usefulness of Pkmsp-1 block IV in assessing the MOI of P. knowlesi in clinical isolates from Malaysia. Two allele-specific PCR primer pairs targeting the two allelic families of block IV (T1 and T2) were designed, and used to genotype P. knowlesi in 200 blood samples (100 from Peninsular Malaysia and 100 from Malaysian Borneo). Results showed that the mean MOI in Malaysian Borneo was slightly higher as compared to Peninsular Malaysia (1.58 and 1.40, respectively). Almost half of the total blood samples from Malaysian Borneo (52%) had polyclonal infections (i.e., more than one allele of any family type) as compared to Peninsular Malaysia (33%) samples. The T1 allelic family was more prevalent in Peninsular Malaysia (n=75) than in Malaysian Borneo (n=60). The T2 allelic family, however, was more prevalent in the Malaysian Borneo (n=87 vs n=53 respectively). This study shows that the single locus Pkmsp-1 block IV can serve as a simple alternative genetic marker for estimating knowlesi malaria MOI in a population. Future MOI studies should focus on macaque populations as macaques are the natural host of P. knowlesi.

Theileria orientalis Buffeli pathotype in cows in a theileriosis-endemic region of India

@#Oriental theileriosis caused by Theileria orientalis is a growing health concern of lactating cows in its endemic areas. Rapid and sensitive diagnostic tests are demand areas for appropriate and effective prophylactic and therapeutic measures. Quantitative polymerase chain reaction (qPCR) is the answer for both detection and quantification of parasites. Present study deals with qPCR for detection of parasitemia level of T. orientalis in apparently healthy and clinically affected cows. Major piroplasm surface protein (MPSP) gene present in T. orientalis was cloned in pUC57 vector and transformed into E. coli Top 10 cells. Single and mixed infections of hemoprotozoa other than T. orientalis, causing anemia were differentiated through blood smear examination and PCR tests. T. orientalis was detected in 108 (63.15%) ill and 48 (26.66%) healthy cows. Piroplasms detected per 1000 red blood cells (RBCs) was 0-1 in the healthy group as compared to 3-22 in those showing clinical signs. Parasitemia in ill cows ranged between 6.9 × 102 and 4.5 × 103 parasites / µl of blood which was significantly higher (p<0.05) than healthy group (2.6 × 102 - 5.7 × 102 parasites / µl of blood). Phylogenetic study of the isolates showed similarity with Buffeli type that unfolded its pathogenic form in apparently healthy and ill cows.

Study of impact of Wolbachia surface protein on reactive oxygen species production in HepG2 cell line exposed to ethanol

Objective: To study the impact of Wolbachia surface protein (WSP) on reactive oxygen species (ROS) level inethanol (EtOH)-exposed HepG2 cells.Materials and Methods: Increase in ROS level was induced in HepG2 cells by subjecting HepG2 cells toEtOH exposure. Impact of WSP on ROS level was examined by staining of intracellular ROS in cells usingthe specific ROS-detecting dye 2ʹ, 7ʹ-dichlorodihydrofluorescein diacetate (H2DCFDA), followed by flowcytometric analysis.Results and Conclusion: Flow cytometry analysis using H2DCFDA-based staining study of ROS level inHepG2 cells revealed that EtOH caused oxidative stress in HepG2 cells by inducing production of high levelsof ROS. However, EtOH-induced increased ROS production in cells decreased with treatment of WSP.From the current study, we can culminate that WSP provides cytoprotective action against EtOH-inducedincreased ROS production and oxidative stress in HepG2 cells by decreasing ROS production. This will beof significance for the treatment of EtOH-related liver ailments. Thus, this article emphasizes that WSP withprotecting ability could be used as a powerful therapeutic drug to treat EtOH-related liver ailments.

Preparation of monoclonal antibodies against pneumococcal polysaccharide and hepatitis B virus surface protein / 中华微生物学和免疫学杂志

Objective@#To prepare monoclonal antibodies against pneumonia serotype 33F polysaccharides (Pn33Fps) and hepatitis B virus (HBV) surface proteins (HBs) by using the conjugate of Pn33Fps and HBs as antigen.@*Methods@#The conjugate of Pn33Fps and HBs was used as antigen to immunize mice with different immune doses, different immune procedures and different immune sites. Mouse spleen cells with higher antibody level after immunization were isolated and fused with SP2/0 myeloma cells. The hybridoma cells were screened specifically with Pn33Fps or HBs to prepare corresponding monoclonal antibodies.@*Results@#Serum antibodies against Pn33Fps and HBs were induced by immunizing mice with the conjugate. Monoclonal cell lines capable of continuously expressing antibodies against Pn33Fps or HBs were obtained. It has been proved that the recovery rates of samples of Pn33Fps and HBs prepared in three batches tested with ascites monoclonal antibodies prepared by these two monoclonal cell lines were between 95% and 105%.@*Conclusions@#Monoclonal antibodies against Pn33Fps and HBs could be prepared simultaneously by immunizing mice with the conjugate of Pn33Fps and HBs and used for the quantitative detection of Pn33Fps and HBs.

Screening, preparation and identification of a broad-spectrum monoclonal antibody against Strepto-coccus pneumoniae surface protein A / 中华微生物学和免疫学杂志

Objective To screen and prepare a broad-spectrum monoclonal antibody against Strep-tococcus pneumoniae ( S. pneumoniae) surface protein A ( PspA) and to evaluate its potential in clinical prac-tice. Methods Hybridoma cells were screened and inoculated into the abdominal cavities of BALB/c mice to prepare antibodies in ascites. Monoclonal antibodies were obtained by ammonium sulfate precipitation and protein A affinity chromatography and then identified by SDS-PAGE and Western blot. Their specificity, iso-forms and killing activities in vitro were analyzed. Results A broad-spectrum monoclonal antibody that rec-ognized PspA subclasses 2, 3 and 4 was obtained. Its in vitro killing rate against S. pneumoniae reached 40. 3％. Conclusions A broad-spectrum monoclonal antibody that could specifically bind to PspA was suc-cessfully prepared with a strong in vitro killing activity. This study provided reference for clinical diagnosis of S. pneumoniae-related diseases, quality assessment of S. pneumoniae vaccines and further research on mono-clonal antibody therapeutics.

Low Levels of Polymorphisms and Negative Selection in Plasmodum knowlesi Merozoite Surface Protein 8 in Malaysian Isolates

Human infections due to the monkey malaria parasite Plasmodium knowlesi is increasingly being reported from most Southeast Asian countries specifically Malaysia. The parasite causes severe and fatal malaria thus there is a need for urgent measures for its control. In this study, the level of polymorphisms, haplotypes and natural selection of full-length pkmsp8 in 37 clinical samples from Malaysian Borneo along with 6 lab-adapted strains were investigated. Low levels of polymorphism were observed across the full-length gene, the double epidermal growth factor (EGF) domains were mostly conserved, and non-synonymous substitutions were absent. Evidence of strong negative selection pressure in the non-EGF regions were found indicating functional constrains acting at different domains. Phylogenetic haplotype network analysis identified shared haplotypes and indicated geographical clustering of samples originating from Peninsular Malaysia and Malaysian Borneo. This is the first study to genetically characterize the full-length msp8 gene from clinical isolates of P. knowlesi from Malaysia; however, further functional characterization would be useful for future rational vaccine design.

Preparation of monoclonal antibodies against pneumococcal polysaccharide and hepatitis B virus sur-face protein / 中华微生物学和免疫学杂志

Objective To prepare monoclonal antibodies against pneumonia serotype 33F polysac-charides (Pn33Fps) and hepatitis B virus ( HBV) surface proteins ( HBs) by using the conjugate of Pn33Fps and HBs as antigen. Methods The conjugate of Pn33Fps and HBs was used as antigen to immu-nize mice with different immune doses, different immune procedures and different immune sites. Mouse spleen cells with higher antibody level after immunization were isolated and fused with SP2/0 myeloma cells. The hybridoma cells were screened specifically with Pn33Fps or HBs to prepare corresponding monoclonal antibodies. Results Serum antibodies against Pn33Fps and HBs were induced by immunizing mice with the conjugate. Monoclonal cell lines capable of continuously expressing antibodies against Pn33Fps or HBs were obtained. It has been proved that the recovery rates of samples of Pn33Fps and HBs prepared in three bat-ches tested with ascites monoclonal antibodies prepared by these two monoclonal cell lines were between 95％ and 105％. Conclusions Monoclonal antibodies against Pn33Fps and HBs could be prepared simul-taneously by immunizing mice with the conjugate of Pn33Fps and HBs and used for the quantitative detection of Pn33Fps and HBs.

Oxidação da proteína dissulfeto isomerase pelo hidroperóxido de urato e as implicações sobre o endotélio vascular / Oxidation of protein disulfide isomerase by urate hydroperoxide and implications in vascular endothelium

Em condições inflamatórias do sistema vascular, altas concentrações de mieloperoxidase somada à presença do ácido úrico, sugerem a formação local do oxidante hidroperóxido de urato. A ação desse peróxido já foi demonstrada sobre glutationa e peroxirredoxinas, tornando plausível a possibilidade de que outras proteínas tiólicas também pudessem ser alvo de oxidação. A proteína dissulfeto isomerase é uma ditiol-dissulfeto oxidoredutase e chaperona, localizada principalmente no retículo endoplasmático, onde participa do enovelamento de proteínas nascentes. Além disso, um pool dessas enzimas foi identificado na superfície da célula e no meio extracelular (secretada) e parece ser especialmente importante em eventos vasculares como ativação e agregação de plaquetas, trombose e remodelamento vascular. Primeiramente, foi investigado se o hidroperóxido de urato era capaz de oxidar a PDI. Pelo ensaio do DTNB foi verificado que os tióis livres da proteína eram consumidos após reação com o peróxido e, em seguida, por nLC-MS/MS os resíduos de cisteínas dos sítios catalíticos foram identificados como os principais alvos de oxidação. Embora não tenham sido verificadas outras modificações além de dissulfetos, foi observado que o tratamento com hidroperóxido promoveu agregação e inativação da proteína. Os estudos subsequentes envolveram uma linhagem de células endoteliais (HUVECs). Análises preliminares de citotoxicidade (detecção da atividade da enzima lactato desidrogenase no sobrenadante e incorporação de sondas fluorescentes ao DNA) mostraram que tratamentos com concentrações de até 400 µM de hidroperóxido de urato não são letais às células em cultura. Usando alquilantes impermeáveis à membrana celular foi mostrado que o hidroperóxido de urato oxida não só a proteína dissulfeto isomerase, mas também proteínas tiólicas totais expressas na superfície das HUVECs. Experimentos de wound healing foram feitos para avaliação da capacidade de migração das células mediante o tratamento com hidroperóxido de urato, mas nenhuma diferença foi observada. Contudo, a incubação das células com os agentes oxidantes hidroperóxido de urato e diamida, inibidores de PDI e integrina e um alquilante de tiol, resultaram, pelo menos nos trinta primeiros minutos, em menor capacidade de adesão das células à fibronectina. Além disso, as células tratadas com hidroperóxido de urato se tornaram mais sensíveis ao destacamento da placa de cultura e apresentaram alteração na morfologia. O tratamento com o peróxido também afetou a homeostase redox das HUVECs, observado pela diminuição da razão GSH/GSSG. Finalmente foram apresentadas evidênciasindiretas de que o ácido úrico é substrato da peroxidasina, uma heme peroxidase abundantemente expressa no sistema vascular. Primeiro, pelo ensaio do Amplex Red foi observado que a presença de ácido úrico na mistura reacional resultou em menor taxa de oxidação do reagente. Depois, por LC-MS/MS, também em amostra na qual o ácido úrico estava presente, foi identificado o hidroxiisourato, álcool resultante da decomposição do hidroperóxido de urato. Todo o conjunto de dados deverá contribuir para o maior entendimento da participação do hidroperóxido de urato em processos oxidativos vasculares − especialmente a oxidação de proteínas − que pode ser um dos mecanismos responsáveis pela alteração da função endotelial e da homeostase vascular

During vascular inflammatory conditions, high amounts of myeloperoxidase added to the presence of uric acid, suggest the local formation of urate hydroperoxide. Its oxidative action has already been demonstrated on glutathione and peroxiredoxins, making plausible the possibility that other thiol proteins could also be a target for oxidation. The protein disulfide isomerase is a dithiol-disulfide oxidoreductase and chaperone, located mainly in the endoplasmic reticulum, where it is involved in the correct folding of nascent proteins. Also, a pool of these enzymes has been identified in cell surface and the extracellular (secreted) milieu and appears to be important in vascular events, such as platelet activation and aggregation, thrombosis and vascular remodeling. First, it was investigated whether urate hydroperoxide was capable of oxidizing PDI. By the DTNB assay, it was found that the free thiols of the protein were consumed after reaction with the peroxide and then, by nLC-MS / MS, the active redox cysteine residues were identified as the main oxidation targets. Although no modifications other than disulfides have been found, hydroperoxide treatment has been shown to promote protein aggregation and inactivation. Subsequent studies involved an endothelial cell line (HUVECs). Preliminary cytotoxicity analyzes (detection of lactate dehydrogenase enzyme activity in the supernatant and incorporation of fluorescent probes into DNA) have shown that treatments with concentrations up to 400 µM are not lethal to cells in culture. Then, using alkylating agents impermeable to the cell membrane, urate hydroperoxide was shown to oxidize not only PDI but also total thiol proteins expressed on HUVECs surface. Wound healing experiments were performed to evaluate cell migration after treatment with urate hydroperoxide, but no difference was observed. However, incubation of the cells with the oxidizing agents urate hydroperoxide and diamide, inhibitors of both PDI and integrin and a thiol alkylator, resulted, at least for the first thirty minutes, in reduced cell adhesion to fibronectin. In addition, cells treated with urate hydroperoxide became more sensitive to detachment from the culture dish and exhibited alterations in morphology. Treatment with the peroxide also affected the redox homeostasis of the HUVECs, observed by a decrease in the GSH / GSSG ratio. Finally, indirect evidence was presented that uric acid is a substrate of peroxidasin, a heme peroxidase abundantly expressed in the vascular system. First, with the Amplex Red assay it was observed that the presence of uric acid in the reaction mixture resulted in lower oxidation rates of the reagent. Then, by LC-MS / MS, hydroxyisourate, which is the alcohol derived from urate hydroperoxide decomposition, was also identified in samples containing uric acid. Taken together, the data presented should contribute to a better understanding of the involvement of urate hydroperoxide in vascular oxidative processes − especially protein oxidation − that may be one mechanism associated to disturbances in endothelial function and vascular homeostasis

Molecular Dynamics, Simulation of Protein-Protein Complex and their Role in Cytoprotective Process in Ethanol-induced Toxicity of HepG2 Cell Line

Aim: To examine the protein-protein interaction of Wolbachia Surface Protein (WSP of Uzifly) with six proteins involved in Ethanol-induced toxicity and the proteins involved in its cytoprotective process in HepG2 cell line (CYP2E1, Superoxide dismutase, Catalase, Death-associated protein kinase1, Alcohol dehydrogenases (Alpha/beta/gamma) and Cytochrome-C) and to study real time molecular dynamics. Methodology: Modelled structure of WSP of Uzifly was retrieved from our laboratory archive. The proteins involved in the Ethanol-induced toxicity and the proteins involved in its cytoprotective process in HepG2 cell line were chosen based on the literature study. The six proteins like CYP2E1, Superoxide dismutase, Catalase, Death-associated protein kinase1, Alcohol dehydrogenases (Alpha/beta/gamma) and Cytochrome-C which are involved in the Ethanol-induced toxicity and the proteins involved in its cytoprotective process in HepG2 cell line were retrieved from PDB database with ID: PDB (3T3Z), PDB (2C9V), PDB (1DGG), PDB (2YAK), PDB (1U3W) and PDB (3NWV) respectively. Docking study was processed using ZDOCK and the best poses of protein were sorted using rDock. Finally, the atomic level interaction was studied for the best-scored protein-protein complex. The best complex was further subjected to molecular dynamics simulation to study its stability using standard dynamics cascade tool. Results: From the results, it was observed that three proteins such as Cytochrome-C, CYP2E1 and Superoxide dismutase have more favourable shape complementarity for WSP binding to exhibit the cytoprotective process. However, the interaction analysis was done only for the top complex, Cytochrome-C-WSP. Time dependent parameter analysis of best complex Cytochrome-C-WSP showed that root-mean-square deviation (RMSD) values initially deviated but it was stabilized at the end of 1ns dynamics. The radius of gyration (Rg) during dynamics was within the limit. Conclusion: This insilico study revealed that WSP has cytoprotective potential and therapeutical application.

Change and significance of serum inflammatory cytokines and pulmonary surface proteins in respiratory failure of full-term infants / 中国新生儿科杂志

Objective To study the changes and significance of inflammatory cytokines and pulmonary surface protein (SP) level in respiratory failure of full-term infants.Method Prospectively selected 30 cases of term baby with respiratory failure requiring mechanical ventilation and pulmonary surfactant (PS) treatment in BaYi Children's Hospital from May 2016 to January 2017 as case group,while 30 cases of term baby with transient tachypnea or hypoglycemia were control group.Blood samples were collected at the first and third day of hospitalization.The interleukin-6 (IL-6),IL-10,and tumor necrosis factor-α (TNF-α) were detected by flow cytometry,serum SPs were detected by enzyme-linked immunosorbent assay method.The statistical analyses were conducted by SPSS 22.0 software.Result The levels of IL-6,IL-10,SP-A,SP-B and SP-C in the case group were significantly higher than those in the control group [IL-6:172.4 (58.4,668.4) ng/L vs.8.3 (5.7,11.2) ng/L,IL-10:10.2 (5.9,31.5) ng/L vs.4.7 (3.6,7.1) ng/L,SP-A:6.94 (2.37,29.64) μg/L vs.0.56 (0.50,0.64) μg/L,SP-B:4.36 (1.99,5.25)μg/L vs.1.44 (1.25,1.79) μg/L,SP-C:0.87 (0.19,2.66) μg/L vs.0.14 (0.10,0.16) μg/L,P ＜0.05].After exogenous PS treatment,serum SP-A,SP-B,SP-C,IL-6 and IL-10 levels in the surviving group were significantly lower comparing with the first day (P ＜ 0.05).The IL-6,SP-A and SP-C levels in the first day death group were significantly higher than those in survival group(P ＜ 0.05).Conclusion Inrespiratory failure of full-term infants,serum IL-6 levels are consistent with the SP-A and SP-C levels,and a sustained increase may serve as a potential early biomarker for disease progression.

Genetic Diversity and Natural Selection in 42 kDa Region of Plasmodium vivax Merozoite Surface Protein-1 from China-Myanmar Endemic Border

Plasmodium vivax merozoite surface protein-1 (PvMSP1) gene codes for a major malaria vaccine candidate antigen. However, its polymorphic nature represents an obstacle to the design of a protective vaccine. In this study, we analyzed the genetic polymorphism and natural selection of the C-terminal 42 kDa fragment within PvMSP1 gene (Pv MSP142) from 77 P. vivax isolates, collected from imported cases of China-Myanmar border (CMB) areas in Yunnan province and the inland cases from Anhui, Yunnan, and Zhejiang province in China during 2009–2012. Totally, 41 haplotypes were identified and 30 of them were new haplotypes. The differences between the rates of non-synonymous and synonymous mutations suggest that PvMSP142 has evolved under natural selection, and a high selective pressure preferentially acted on regions identified of PvMSP133. Our results also demonstrated that PvMSP142 of P. vivax isolates collected on China-Myanmar border areas display higher genetic polymorphisms than those collected from inland of China. Such results have significant implications for understanding the dynamic of the P. vivax population and may be useful information towards China malaria elimination campaign strategies.

Value of combined detection of serum IL-8 ,TNF-α,KL-6 and SP-D in assisted diagnosis of idiopathic pulmonary fibrosis / 国际检验医学杂志

Objective To study the clinical value of combined detection of serum interleukin(IL)-8 ,tumor necrosis factor(TNF)-α,alvedar cell surface antigen Ⅱ(KL-6) and surface protein D(SP-D) in the diagnosis of idiopathic pulmonary fibrosis(IPF) .Meth-ods Seventy three patients with IPF were selected as the research subjects ,other 73 patients with bacterial pneumonia were taken as the bacterial pneumonia group .The levels of serum IL-8 ,TNF-α,KL-6 and SP-D were detected by enzyme-linked immunosorbent assay (ELISA) .The serum levels of IL-8 ,TNF-α,KL-6 and SP-D were compared between the IPF group and bacterial pneumonia group .The sensitivity and specificity of IPF detection were compared between the 4-index combined detection and single item de-tection .Results The levels of IL-8 ,TNF-α,KL-6 and SP-D in the IPF group were significantly higher than those in the bacterial pneumonia group (P<0 .05) .The positive rate of single detection of four indexes in the IPF group was significantly higher than that in the bacterial pneumonia group (P<0 .05) .The sensitivity and specificity of the 4-index combined detection for diagnosing IPF were 90 .4% and 93 .2% respectively ,which were significantly higher than the those of single index detection (P<0 .05) .Con-clusion The combined detection of IL-8 ,TNF-α,KL-6 and SP-D has better sensitivity and specificity in IPF diagnosis compared with single detection of IL-8 ,TNF-α,KL-6 and SP-D .

Characterization of Pv92, a Novel Merozoite Surface Protein of Plasmodium vivax

The discovery and understanding of antigenic proteins are essential for development of a vaccine against malaria. In Plasmodium falciparum, Pf92 have been characterized as a merozoite surface protein, and this protein is expressed at the late schizont stage, but no study of Pv92, the orthologue of Pf92 in P. vivax, has been reported. Thus, the protein structure of Pv92 was analyzed, and the gene sequence was aligned with that of other Plasmodium spp. using bioinformatics tools. The recombinant Pv92 protein was expressed and purified using bacterial expression system and used for immunization of mice to gain the polyclonal antibody and for evaluation of antigenicity by protein array. Also, the antibody against Pv92 was used for subcellular analysis by immunofluorescence assay. The Pv92 protein has a signal peptide and a sexual stage s48/45 domain, and the cysteine residues at the N-terminal of Pv92 were completely conserved. The N-terminal of Pv92 was successfully expressed as soluble form using a bacterial expression system. The antibody raised against Pv92 recognized the parasites and completely merged with PvMSP1-19, indicating that Pv92 was localized on the merozoite surface. Evaluation of the human humoral immune response to Pv92 indicated moderate antigenicity, with 65% sensitivity and 95% specificity by protein array. Taken together, the merozoite surface localization and antigenicity of Pv92 implicate that it might be involved in attachment and invasion of a merozoite to a new host cell or immune evasion during invasion process.

Relation between adherence factors and the phylogenetic group of extraintestinal pathogenic Escherichia coli / Шинэ санаа Шинэ нээлт

Extraintestinal pathogenic Escherichia coli (ExPEC), the specialized strains ofE.coli that cause most extraintestinal infections, represent a major but littleappreciated health threat. Phylogenetic analysis has shown that ExPEC is composedof four main phylogenetic groups (A,B1, B2, and D) and that virulent extraintestinalstrains mainly belong to groups B2 and D.In this study, we aimed to assess therelation between adherence virulence and phylogenetic groups of ExPEC.A total of 161 E.coli samples were collected. Out of these 17 (10.6%) werefrom pus, 66 (41 %) from urine, 78 (48.4%) from cervical swab. The phylogeneticgroups and 6 virulence genes (fimH, papC, papGII, papGIII, fa/draBC,andSfa/focDE) encoding adhesins were identified by triplex PCR. Phylogeneticgroups distribution was as follows: B1 10.5%, A 24.7%, B2 25.3%, and D 38.9%. Virulence genes prevalence was fimH 90.1%, papC 23%, papGII 16.8%, papGIII1.9%, Afa/draBC 11.8%, andSfa/focDE 5.6%. The cell surface protein (curli) wasdetected 50,3% by Congo red agar. In conclusion: The most isolated strainsbelonged to the phylogenetic group B2 and D. The phylogenetic groups weresignificantly associated with some genes encodingadhesins (fimH, papC) and cellsurface protein (curli).

Limited genetic diversity among Plasmodium falciparium isolates using nested PCR in Jazan Area, Saudi Arabia

Objective: To establish molecular characterization of Plasmodium falciparum field isolates in Jazan Area of Saudi Arabia measured with highly polymorphic genetic marker, i.e. the merozoite surface protein 2 (MSP 2). Methods: Blood samples were collected from 128 clinically suspected patients attending both Jazan and Sabia hospitals, Kingdom of Saudi Arabia. Both hospitals reflected urban and rural settings respectively. Analysis of central polymorphic region of MSP 2 (3D7 and FC27 allelic families) was performed using nested PCR for malaria patients. Results: For MSP 2 allelic families of Plasmodium falciparum, 16 cases (53.3%) carried FC27 type and 14 cases (46.7%) carried 3D7 type, whereas no malaria cases harbored both allelic types. The present study showed that in urban area, 80% of FC27 fragments were 500 bp while in rural area it was 45.5% (P = 0.08). The FC27 400 bp allele was more prevalent in patients from rural than those from the urban area (P = 0.08). The most prevalent infecting 3D7 allele was the 3D7 300 bp in both areas. In the present study, there were no multiple infections. Conclusions: The limited genetic diversity which was observed in Jazan (considered as an endemic area) may be attributed to the small sample size or sustained malaria control program.

Allelic Diversity and Geographical Distribution of the Gene Encoding Plasmodium falciparum Merozoite Surface Protein-3 in Thailand

Merozoite surface proteins (MSPs) of malaria parasites play critical roles during the erythrocyte invasion and so are potential candidates for malaria vaccine development. However, because MSPs are often under strong immune selection, they can exhibit extensive genetic diversity. The gene encoding the merozoite surface protein-3 (MSP-3) of Plasmodium falciparum displays 2 allelic types, K1 and 3D7. In Thailand, the allelic frequency of the P. falciparum msp-3 gene was evaluated in a single P. falciparum population in Tak at the Thailand and Myanmar border. However, no study has yet looked at the extent of genetic diversity of the msp-3 gene in P. falciparum populations in other localities. Here, we genotyped the msp-3 alleles of 63 P. falciparum samples collected from 5 geographical populations along the borders of Thailand with 3 neighboring countries (Myanmar, Laos, and Cambodia). Our study indicated that the K1 and 3D7 alleles coexisted, but at different proportions in different Thai P. falciparum populations. K1 was more prevalent in populations at the Thailand-Myanmar and Thailand-Cambodia borders, whilst 3D7 was more prevalent at the Thailand-Laos border. Global analysis of the msp-3 allele frequencies revealed that proportions of K1 and 3D7 alleles of msp-3 also varied in different continents, suggesting the divergence of malaria parasite populations. In conclusion, the variation in the msp-3 allelic patterns of P. falciparum in Thailand provides fundamental knowledge for inferring the P. falciparum population structure and for the best design of msp-3 based malaria vaccines.

Molecular cloning and expression of OspC protein of a Chinese Borrelia afzelli FP1 strain and pre-liminary study on the immune protectivity of the rOspC protein / 中华微生物学和免疫学杂志

Objective To clone and express the outer surface protein C ( OspC) from a Chinese Borrelia afzelli FP1 strain and to evaluate the immune protectivity of the recombinant OspC protein ( rOspC) . Methods The gene encoding OspC protein of Borrelia afzelli FP1 strain was amplified by polymerase chain reaction (PCR) and then inserted into pET-30a plasmid to construct the recombinant expression plasmid pET-30a-OspC. The transformed E. coli BL21 strains carrying pET-30a-OspC plasmid were induced by IPTG to express OspC protein. The expressed proteins were purified by Ni-IDA resin chromatography and analyzed by SDS-PAGE and Western blot assay. Indirect immunofluorescence assay ( IFA) was performed to detect anti-rOspC protein antibodies in serum samples from rabbits immunized with rOspC protein. In vitro neutral-ization test was performed for evaluation the immune protectivity of rOspC protein. Results The recombi-nant expression plasmid pET-30a-OspC was successfully constructed and highly expressed in E. coli BL21. A strong antigen-antibody reaction between the rOspC protein and polyclonal antibody against Borrelia afzelli FP1 strain was detected by Western blot assay. The titers of IgG in serum samples from rabbits immunized with rOspC protein were significantly elevated. The in vitro neutralization test indicated that 106/ml of Borre-lia afzelli FP1 strains were neutralized by every anti-OspC protein serum sample from the experiment group. Conclusion The rOspC protein showed a strong immune protectivity against Borrelia afzelli, which could be used in the development of polyvalent subunit vaccine against lyme disease.

Preparation and immunogenicity analysis of a recombinant pneumococcal surface protein / 中华微生物学和免疫学杂志

Objective To prepare a recombinant pneumococcal surface protein A clade 4 ( PspA4) and to analyze its immunogenicity.Methods The gene encoding PspA4 protein was synthesized and inserted into pET-20b to construct the recombinant expression plasmid.The transformed E.coli strains carrying expression plasmid were induced to express PspA4 protein.ELISA was performed to analyze the ti-ters of PspA4-specific IgG in a mouse model.Results The recombinant PspA4 protein of high purity ( 90%) was successfully prepared.The titers of PspA4-specific antibody in mice received PspA4 immuniza-tion were 106 times higher than those of the blank control group, suggesting that the expressed PspA4 protein had the advantage of high immunogenicity.Conclusion This study suggested that the PspA4 protein might be used as one of the candidate protein for the development of pneumovax and laid a foundation for further in-vestigation on pneumococcal protein based vaccine.

Preparation of a fusion protein with pneumococcal surface protein A of two different clades of familyⅠand analysis of immunogenicity of the recombinant protein / 中华微生物学和免疫学杂志

Objective To construct a recombinant fusion protein with pneumococcal surface pro-tein A (PspA) of Stretococcus pneumonia (SPN) familyⅠclade 1 and 2, and to analyze the immunogenici-ty of the fusion protein.Methods The gene fragments encoding theα-helix of PspA of the two clades were amplified by PCR and then inserted into the expression vector pET-27b(+) to construct the recombinant ex-pression plasmid.The transformed Escherichia coli BL21 strains carrying expression plasmid were induced by IPTG to express the recombinant protein.The titers and affinity of antibodies against PspA protein were measured by ELISA.An opsonophagocytic assay and an animal experiment were performed to evaluate the immunogenicity of the recombinant protein.Results Double enzyme cutting and gene sequencing confirmed the two purpose gene fragments were correctly expressed in the expression vector pET-27b(+).The titers of anti-PspA antibody in the serum of Kunming ( KM) mice immunized with the fusion protein were 1 ×104 . The affinity of anti-PspA antibody reached to 2×105 .The rates of recombinant PspA6B-PspA05 protein me-diated phagocytosis for SPN6B, SPN05 and SPN01 strains were 20%, 15% and 8.8%, respectively.No SPN23F strain was engulfed by macrophages upon the stimulation with PspA6B-PspA05 protein.The survival rates of mice injected with SPN05, SPN6B, SPN01 and SPN23F strains were respectively 75%, 92%, 75%and 33%upon the immunization of PspA6B-PspA05 protein.Conclusion The recombinant fusion protein PspA6B-PspA05, constructed with the PspA proteins of Stretococcus pneumonia familyⅠclade 1 and 2, was successfully expressed in the E.coli prokaryotic system with the advantage of high immunogenicity.High ti-ters of anti-PspA antibodies with high specificity were induced in KM mice upon the stimulation with Ps-pA6B-PspA05 protein.Moreover, a cross-protective immunity was induced in KM mice upon the immuniza-tion with PspA6B-PspA05 protein.

Relation between adherence factors and the phylogenetic group of extraintestinal pathogenic Escherichia coli / Шинэ санаа Шинэ нээлт

Extraintestinal pathogenic Escherichia coli (ExPEC), the specialized strains ofE.coli that cause most extraintestinal infections, represent a major but littleappreciated health threat. Phylogenetic analysis has shown that ExPEC is composedof four main phylogenetic groups (A,B1, B2, and D) and that virulent extraintestinalstrains mainly belong to groups B2 and D.In this study, we aimed to assess therelation between adherence virulence and phylogenetic groups of ExPEC.A total of 161 E.coli samples were collected. Out of these 17 (10.6%) werefrom pus, 66 (41 %) from urine, 78 (48.4%) from cervical swab. The phylogeneticgroups and 6 virulence genes (fimH, papC, papGII, papGIII, fa/draBC,andSfa/focDE) encoding adhesins were identified by triplex PCR. Phylogeneticgroups distribution was as follows: B1 10.5%, A 24.7%, B2 25.3%, and D 38.9%. Virulence genes prevalence was fimH 90.1%, papC 23%, papGII 16.8%, papGIII1.9%, Afa/draBC 11.8%, andSfa/focDE 5.6%. The cell surface protein (curli) wasdetected 50,3% by Congo red agar. In conclusion: The most isolated strainsbelonged to the phylogenetic group B2 and D. The phylogenetic groups weresignificantly associated with some genes encoding adhesins (fimH, papC) and cellsurface protein (curli).