Table of Content

30 June 2007, Volume 25 Issue 3

Previous Issue    Next Issue

述评

Inheritance and development of “traditional” parasitology

YuSen-hai

2007, 25(3):  1-162. 

Asbtract ( )   PDF (190KB) ( )  

Related Articles | Metrics

论著

Cloning， Expression and Analysis of the Heat Shock Protein of Cryptosporidium andersoni

LIUHai-peng;CAOJian-ping;LIXiao-hong;LUWei-yuan;SHENYu-juan;XUYu-xin;ZANGWei;LIUShu-xian

2007, 25(3):  2-170. 

Asbtract ( )   PDF (190KB) ( )  

Related Articles | Metrics

Objective To clone and express the partial encoding sequence of Mr 70 000 heat shock protein of Cryptosporidium andersoni （CaHSP70） in Escherichia coli and identify the recombinant protein. Methods Total RNA was extracted from oocysts of C.andersoni isolated from Xuzhou， Jiangsu （XZ-BOV）. The CaHSP70 gene was amplified by RT-PCR. The PCR product was cloned and then subcloned into pET28a vector， and the recombinant plasmids were transformed into E.coli BL21（DE3） subsequently. The expressed protein induced by IPTG was purified and identified by SDS-PAGE and western blotting， and was further analyzed by relevant bioinformatics softwares. The specific IgG antibodies in mice immunized by rCaHSP70 were detected by western blotting and ELISA respectively. Results The deduced amino acid sequence showed to be identical with that of C. andersoni Mr 70 000 heat shock protein （HSP70）. The recombinant protein expressed in the form of inclusion body was about Mr 43 000. It could be recognized by anti-His G labeled HRP antibodies and all the sera from mice infected with C. andersoni and children infected with C. parvum as well as sera from mice immunized with rCaHSP70 respectively. The rCaHSP70 possibly had multiple domains and potential antigenic determinants. Phylogenetic analysis showed that XZ-BOV and C. andersoni were in the same clade. ELISA showed that the level of specific antibodies against rCaHSP70 in immunized BALB/c and C57BL/6 mice was significantly higher than that of mice before immunization. Conclusion The recombinant plasmid pET28a-CaHSP70 has been constructed. The purified rCaHSP70 exhibits high antigenicity and seems a potential candidate antigen for immunodiagnosis of cryp-tosporidiosis.

Anti-Trichinella Antibody Level in Muscle Juice of Experimentally Infected Mice

WANGZhong-quan;LAILi-hong;CUIJing

2007, 25(3):  3-174. 

Asbtract ( )   PDF (291KB) ( )  

Related Articles | Metrics

【Abstract】 Objective To detect the anti-Trichinella antibody level in muscle juice of experimentally infected mice and their correlation with serum antibodies. Methods Two hundred and eighty-eight Kunming mice were randomly divided into 3 groups （96 mice each）， each mouse was inoculated with 100， 300 or 500 muscle larvae of T.spiralis， respectively. Anti-Trichinella antibodies in serum and muscle juice taken weekly up to 18 weeks post-infection （wpi） were detected by ELISA using T.spiralis muscle larval excretory-secretory （ES） antigens. Thirty mice were inoculated with T. spiralis muscle larvae（500 larvae each）. The muscle samples taken in 6 wpi were kept in plastic containers and conserved at 4 ℃ for 7 days or at -20 ℃ for 20 weeks for detecting anti-Trichinella antibodies later. Results Anti-Trichinella antibodies in muscle juice of the mice infected with 100， 300 or 500 larvae were detected in 4， 3 and 3 wpi， with antibody positive rate of 87.5%， 50% and 87.5% respectively. In the three groups of mice， the antibody positive rate of muscle juice increased gradually after infection and up to 100% in 6， 4 and 4 wpi， and the antibody level reached its peak in 8 wpi with an absorbance value of 0.43， 0.49 and 0.52 respectively. Thereafter， the antibody level decreased slightly， but the positive rate was still 100% and lasted to 18 wpi when the experiment was ended. The antibody level in muscle juice showed significant positive correlation with serum antibodies at different time intervals after infection in three groups （r₁₀₀=0.940， r₃₀₀=0.970， r₅₀₀=0.983， P<0.05）. The absorbance value of muscle samples conserved at 4 ℃ for 7 d and 1 d was the same （0.53） （F=0.250， P>0.05）, and those conserved at -20 ℃ for 8 wk and 1 wk was 0.46 and 0.50 respectively， showing that the antibody level in muscle juice did not decreased considerably after the muscle samples were frozen at -20 ℃ for 8 weeks （F=2.273， P>0.05）. The absorbance value of Trichinella-infected muscle conserved at -20 ℃ for 10 wk decreased to 0.43， with significant difference from that conserved at -20 ℃ for 1 wk， but the positive rate was also 100%， and antibodies were detected in all muscle samples conserved at -20 ℃ for 20 weeks when the experiment was ended. Conclusion When animals died or were slaughtered and serum samples could not be collected， muscle juice can be collected from fresh， cool and frozen meat and used as a substitute sample for detecting anti-Trichinella antibodies.

Effectiveness of Routinely Used Assays for the Diagnosisof Schistosomiasis japonica in the Field

XUJing;CHENNian-gao;FENGTing;WANGEn-mu;WUXiao-hua;CHENHong-gen;WANGTian-ping;ZHOUXiao-nong;ZHENGJiang

2007, 25(3):  4-179. 

Asbtract ( )   PDF (293KB) ( )  

Related Articles | Metrics

【Abstract】 Objective To evaluate the effectiveness of routinely used assays for schistosomiasis diagnosis in the field. Methods From late November to early December 2005， 6-65 years old inhabitants from 3 endemic villages were examined by Kato-Katz technique （3 thick smears） and nylon bag sedimentation/hatching method. At the same time， dipstick dye immunoassay（DDIA）， fast enzyme linked immunosorbent assay （F-ELISA）， indirect haemagglutination test A （IHA-A） and B （ IHA-B） were carried out in parallel. Results 1 864 people were examined by stool examination with an average positive rate of 9.7%. The missing rate of DDIA was relatively stable in medium and heavily endemic areas of schistoso-miasis. The missing rate of nylon bag sedimentation/hatching method was 25% and relatively stable when the number of eggs per gram of feces（EPG） was larger than 100. The average positive rate of DDIA， F-ELISA， IHA-A and IHA-B was 47.8%， 50.0%， 66.3% and 40.1% respectively. Using stool examination as the gold standard， the sensitivity of DDIA， F-ELISA， IHA-A and IHA-B was 75.3％， 65.8％， 85.6％ and 76.0%; and the specificity was 55.1％， 51.7％， 35.7% and 63.6％， respectively. Among the four sero-diagnostics， the specificity， Youden index， positive likelihood rate and coincidence of IHA-B were the highest. Conclusion Kato-Katz method is more stable and effective than nylon bag sedimentation/hatching method in medium and heavily endemic areas of schistosomiasis japonica. The sensitivity and spec-ificity of these four diagnosis kits are lower than 90%.

Potential Risks for Transmission of Schistosomiasis Caused by Mobile Population in Shanghai

ZHOUXiao-nong;CAILi;ZHANGXiao-ping;SHENGHui-feng;MAXing-bao;JINYan-jun;WUXiao-hua;WANGXian-hong;WANGLong-ying;LINTao;SHENWei-guo;LUJing-qing;DAIQing

2007, 25(3):  5-184. 

Asbtract ( )   PDF (260KB) ( )  

Related Articles | Metrics

【Abstract】 Objective To understand the potential risk for schistosomiasis transmission caused by introduction of infection source from mobile population in Shanghai. Methods Field investigation was conducted in the suburb of Shanghai City by screening the mobile population living in Shanghai for more than 1 month and over 1 years old in a procedure of interviewing， serum indirect hemagglutination （IHA） test， and then fecal examination to detect the eggs with nylon sedimentation approach for those IHA positives. Results Among 2 931 mobile people investigated， 1 575 were male （53.74%） and 1 356 were female（46.26%）; 138 out of 2 931 were positive in IHA test （4.71%）. 1 938 （66.12%） out of 2 931 came from Schistosoma japonicum-endemic provinces and its positive rate in mobile population （5.99%） was significantly higher than those from the transmission-interrupted provinces （2.6%） （χ²=10.28, P＜0.01）， and those from non-endemic provinces （1.68%） （χ²=12.86, P＜0.01）. The 138 IHA positives all showed negative in fecal examination. In accordance with the serum positive rate and egg-infection rate in the national reporting system in 2004， it was estimated that there would be about 13 356 and 1 699 potential serum positive cases respectively from endemic area and transmis-sion controlled area， and about 2 168 and 255 egg-positive cases from the two kind areas respectively, majority of the cases were from Anhui Province. Conclusion Schistosomiasis transmission risks potentially exist in Shanghai suburb due to the introduction of infected mobile people from other endemic provinces， and a surveillance system and quick response are needed for the possible re-emergence of the disease.

Apoptosis of Human Leukemia K562 Cell in vitroInduced by Toxoplasma gondii

ZHANGXiu-chang;CAINian-guang;SUNLi;LUOQiang;ANFang

2007, 25(3):  6-188. 

Asbtract ( )   PDF (295KB) ( )  

Related Articles | Metrics

【Abstract】 Objective To investigate whether the Toxoplasma gondii can inhibit proliferation of human leukemia K562 cells and/or induce apoptosis of the cells in vitro. Methods K562 cells （5×10⁴/ml） were harvested at mid-exponential phase and planted in 96 well plates with 100 μl each and in 50 ml culture bottles, 1.5 ml each. The cells were treated for 48 hours with different concentration of Toxoplasma tachyzoites. Growth inhibition rate was measured with MTT method. Apoptosis was detected through following ways: fluorescence microscopy with Hoechst 33 258 staining was used for observing the change of cell morphology， agarose electrophoresis was used to detect the DNA changes and FCM was used to observe sub-diploid. Results Toxoplasma can inhibit proliferation of K562 cells. K562 cells treated with Toxoplasma presented an inhibition rate of 17%, 28%， 48%， 50% and 55% under the tachyzoite concentration of 1×10⁴， 2×10⁴， 4×10⁴， 8×10⁴ and 16×10⁴/ml respectively, with a significant difference to the control （t=3.606, 5.918， P<0.05； t=9.171,7.841 and 7.067， P<0.01）. Cell contraction and apoptotic bodies were observed under fluorescence microscope. DNA fragment was shown through agarose electrophoresis. Flow cytometric analysis showed an apoptosis peak at 48h. The apoptosis rate was 5.53%, 7.12%, 10.34%, 21.14% and 29.68% respectively. Conclusion Toxoplasma gondii inhibits proliferation and induces cell apoptosis in K562 cells in vitro.

Changes of CD4+CD25+ T Cells in the Spleen of Mice Infected with Toxoplasma gondii

GEYi-yue;ZHANGGai;WUJiang-ping;WANGYong;HUWei;TANMing-juan

2007, 25(3):  7-192. 

Asbtract ( )   PDF (262KB) ( )  

Related Articles | Metrics

【Abstract】 Objective To observe the changes of CD4⁺CD25⁺ regulatory T cells in the spleen of mice infected with T.gondii. Methods Twenty?鄄eight female C57BL/6 mice were randomly divided into four groups. Three groups of mice were inoculated intraperitoneally with 104 tachyzoites in 200 μl sterile PBS. At 2，4 and 6 days post-infection， the spleens were removed. The expression level of Foxp3 mRNA in splenic CD4+ T cells was quantitated by real-time PCR. The percentage of CD4⁺CD25⁺ regulatory T cells in CD4⁺ T cells was determined by flow cytometry， and the absolute numbers of splenic CD4⁺CD25⁺ regulatory T cells and CD4⁺ T cells were assessed. The fourth group was injected intraperitoneally with 200 μl sterile PBS as control. Results The relative mRNA level of Foxp3 in splenic CD4⁺ T cells at day 4 （1.89±0.23） and day 6 （1.79±0.24） post-infection was significantly higher than control （1.00±0.12）（P＜0.01）. After an initial up-regulation at 2 days post-infection （15.07%±2.73%） （P＜0.05）， the proportion of CD4⁺CD25⁺ regulatory T cells in CD4⁺ T cells at day 4 （24.29%±3.19%） and day 6 （19.80%±2.66%） post-infection was significantly higher than control （11.58%±2.04%） （P＜0.01）. At day 6 post-infection， both the percentage of splenic CD4⁺ T cells in splenocytes（5.49%±1.71%） and absolute number of CD4⁺ T cells （1.71±0.44）×10⁶ greatly decreased（P＜0.01）. Conclusion The proportion of splenic CD4⁺CD25⁺ regulatory T cells in CD4⁺ T cells has been up-regulated following T.gondii infection， which is mainly due to a great reduction of CD4⁺ T cells in the spleen.

Production and Identification of Chicken Egg Yolk Antibodies against Soluble Egg Antigen of Schistosoma japonicum

WANGCheng-zu;MOHong-mei;CHENGYu-li;WANGLei;JIANGZi-wei;LIUWen-qi;LIYong-long

2007, 25(3):  8-197. 

Asbtract ( )   PDF (307KB) ( )  

Related Articles | Metrics

【Abstract】 Objective To produce and purify egg yolk immunoglobulin against soluble egg antigen （SEA） of Schistosoma japonicum， and evaluate its specificity and sensitivity. Methods 25-week old hen was intravenously and subcutaneously immunized with SEA of Schistosoma japonicum for 4 times. Each hen was first immunized with 60 μg SEA and subsequent injections were performed at 10-day intervals with 30 μg SEA. IgY was extracted from eggs of hen 35 d after the first inoculation by WD（water-dilution） method， eggs from non-immunized hen were used as negative control. The protein concentration of IgY was measured by BCA method， and IgY was analyzed by SDS-PAGE and Western blotting. SEA-based ELISA was used to evaluate the specificity and sensitivity of the IgY. Results 61 mg IgY was extracted from one egg. The results of SDS-PAGE and Western blotting demonstrated that the IgY contained one major protein band with molecular weight of 130 000 and could be recognized by SEA. Specific IgY could be immediately detected by SDS-PAGE and ELISA in the eggs laid by the hens from 10 days after the first immunization. On day 31 after the primary immunization， the antibody titer reached 1∶1 600. 2.4 ng/ml SEA was detected by IgY based-sandwich ELISA， which indicated a high sensitivity of the purified IgY. Conclusion Anti-SEA IgY with high specificity and sensitivity has been obtained and purified.

Enzyme Histochemistry: The Effect of META-Li on Oncomelania hupensis

ZHUDan;LIHong-jun;LIUHe-xiang;ZHANGYi;GUOjian;LIANGYou-sheng;ZHOUXiao-nong

2007, 25(3):  9-201. 

Asbtract ( )   PDF (341KB) ( )  

Related Articles | Metrics

【Abstract】 Objective To explore the killing mechanism of META-Li against Oncomelania hupensis by observing the change of enzyme activity in snail tissue. Methods Sixty snails were divided into 2 groups. Snails in experiment group were immersed in META-Li （100 mg/L） for 2 d and soft tissue was separated for frozen sections. Histochemical staining for the enzymes CCO，LDH， SDH， AChE and NOS was done by routine method and the average grey density was measured under microscopy. Tissue sections of 10 snails were used to detect grey density for each enzyme. Snails without META-Li treatment served as control. Results The enzyme activity of CCO and AChE in the experiment group was significantly lower than that in the control （t=12.26， P<0.01）， that of LDH and NOS in the experiment group was significantly higher than that in the control （t=3.41， P<0.05）. There was no significant difference on the enzyme activity of SDH between the two groups （t=0.51， P>0.05）. Conclusion The snail-killing effect of META-Li may be relevant to the enzyme activity in energy metabolism and the blocking of the nerve transmission.

实验研究

Bioinformatics Analysis for the Structure and Function of Lactate Dehydrogenase from Schistosoma japonicum

LUGang;YUXin-bing;HUANGCan;XUJing;WUZhong-dao;CHENShou-yi;HUXu-chu

2007, 25(3):  10-205. 

Asbtract ( )   PDF (267KB) ( )  

Related Articles | Metrics

【Abstract】 Objective To predict the structure and function of SjLDH using bioinformatics method. Methods By online analysis at bioinformatics websites such as NCBI（http：//www.ncbi.nlm.nih.gov/） and Expasy （http：//cn.expasy.org/）， and employing software packages such as Vector NTI suite and PCgene to do multi-sequence homological alignment，phylogenetic analysis， secondary structure and topological prediction， homology modeling of tertiary structure， antigenic epitope analysis， etc. Results Same conservative sites and key catalytic sites existed among SjLDH and LDHs from other species. Similarity of SjLDH compared to CsLDH， TvLDH and HsLDH was 75%， 17%， 58%-60% respectively. Phylogenetic analysis demonstrated that the evolution relation between SjLDH and DmLDH was closer than the relation between SjLDH and CeLDH， the relationship between SjLDH and HsLDH-B， -C was closer than HsLDH-A. Three trans-membrane regions were found， the region of 98aa-106aa in three hydrophilia regions located outside of membrane was inferred as the major antigen epitope. This antigen epitope had significant difference with LDHs from protozoon （Pf.， Tg.， Tv.） and had 1-3 amino acid residue difference with MmLDH， HsLDH-A， -B， -C， and was the same with CsLDH. One of the key catalytic residues and substrate （pyruvate） binding loop were located in this region. Tertiary structure demonstrated that 98aa-106aa was on the surface of the protein and formed a substrate binding loop， other two key catalytic sites were at the position near the loop. Conclusion The prediction implied that LDH was an ideal molecule for phylogenetic analysis; SjLDH might be a potential molecular target for immunodiagnosis， anti-schistosome drug and vaccine development.

In vitro Observation on Effect of Nitric Oxide on Exflagellation of Plasmodium yoelii

LIUYing-jie;WANGJi-chun;FENGHui;ZHUXiao-tong;ANChun-li;CAOYa-ming

2007, 25(3):  11-208. 

Asbtract ( )   PDF (281KB) ( )  

Related Articles | Metrics

【Abstract】 Objective To observe the effect of nitric oxide （NO） on exflagellation of malaria parasite. Methods The level of parasitemia and gametocytemia in DBA/2 mice infected with Plasmodium yoelii 17XL was measured by scanning Giemsa-stained blood smears, and the NO level in culture supernatant of splenocytes was checked using Griess reaction. The mice were injected with different doses of NO donor （NOC5） on day 4 post-infection, and control mice were injected with NOC5 precursor. On day 6 post-infection, mice were injected with NOS inhibitor （L-NMMA）, and control mice were injected with D-NMMA and PBS, respectively. Blood samples were collected from tail vein of mice before injection, 30 and 60 min after being injected with NOC5 and NOC5 precursor, 4 and 8 h after being injected with L-NMMA, D-NMMA, and PBS respectively. Exflagellation number of gametocytes in blood culture was counted under microscope. Results The NO level in culture supernatant of splenocytes from mice on day 4 and 6 post-infection was 16.5 mmol/L and 30.4 mmol/L， and exflagellation number was 11.33 and 0.66, respectively. The number of exflagellation in parasitized erythrocytes, obtained from mice on day 4 post-infection， was 5.33 and 2.66， respectively， 30 and 60 min after injection of 1 mg NO donor （NOC5）, significantly lower than that of the control （P＜0.01）. The number of exflagellation in parasitized erythrocytes derived from mice on day 6 post-infection was 1.83， 8 h after the injection of NOS inhibitor （L-NMMA）， which was significantly higher than that of the control （P＜0.01）. Conclusion NO is a major effector molecule resulting in natural transmission-blocking of malaria parasite by directly inhibiting exflagellation of male gametocytes.

Study on the Variation of Lymphocytes and Cytokines in Patients with Echinococcosis granulosus

ZHANGYan;WENHao;LINRen-yong;LUXiao-mei;ZHANGXue;FENGXiao-hui;ZHAOJin-ming;ZHANGJing-ping

2007, 25(3):  12-212. 

Asbtract ( )   PDF (227KB) ( )  

Related Articles | Metrics

【Abstract】 Objective To investigate the variation of lymphocytes and cytokines in patients with cystic echinococcosis （CE）. Methods 80 CE patients who were diagnosed for the first time （60 of Han and 20 of Uygur nationality）， and 37 patients who were to accept the second surgical operation（24 Han and 13 Uygur nationality） were included in the study. The peripheral lymphocytes of patients before operation were analyzed by flow cytometry （FCM） to detect T and B lymphocytes， NK cells bearing surface markers， as well as Th1 cytokine IFN-γ and Th2 cytokine IL-4 in the cytoplasm of lymphocytes. 179 healthy persons served as control. Results In the group of Han patients who were diagnosed for the first time， the percentage of total T cells（CD3⁺） was lower than the control （P<0.05）， while among patients accepting the second operation， the ratio of total T cells showed no difference to the control. For the helper T cells （CD3⁺/CD4⁺）， NK cells （CD3⁺/CD16，56⁺） and B cells （CD3-/CD19⁺）， their ratio were significantly lower in both groups than the control （P<0.01）， but their cytotoxic T cells （CD3⁺/CD8⁺） were higher than the control. In Uygur patients diagnosed for the first time， B cell ratio was lower than that in control （P<0.05）. The NK cell level in both groups of patients was lower than control （P<0.01 and P<0.05 respectively）. The level of Th0 and Th1 showed no statistical difference among the three groups（P＞0.05）. The Th2 level was significantly higher in the first diagnosed patients than control （P<0.01）， but no statistical difference between the group with the second operation and the other two groups. Conclusions The immune status of echinococcosis patients is inhibited and the level of Th1 and Th2 shows difference in the first and second operation groups.

Sensitivity, Specificity and Stability of the Tag-primer Nested/multiplex PCR for Malaria Diagnosis

GUOChuan-kun;LIXue-ming;LIJin-hui;MAOWei;LINZhen;DUJin-fa;HUANGTian-yi

2007, 25(3):  13-216. 

Asbtract ( )   PDF (253KB) ( )  

Related Articles | Metrics

【Abstract】 Objective To improve the sensitivity, specificity and stability of the Tag-primer nested/multiplex PCR for malaria diagnosis. Methods Filter paper blood samples were collected from 30 non-malaria fever patients and 20 infectious disease patients （common cold, influenza, typhoid, hepatitis, etc.）. Four ml blood each taken from one falciparum malaria patient and one vivax malaria patient was serially diluted. Healthy blood sample was used as negative control. Improved direct heating method was used to prepare DNA template. The cytochrome oxidase gene （coxI） located in mitochondrion was selected as target gene. Relevant web resources and software （PUBMED, NCBI-BLAST, Mfold server and Primer Premier 5.0） were employed to design and optimize Tag-primer nested/multiplex PCR （UT-PCR） which was used to test all blood samples. Results A 611 bp band and a 255 bp band were seen in serially diluted infected blood samples （1 000， 100， 10 and 1 parasite/μl） from P.f and P.v patient tested by UT-PCR. The detection limit of either P.falciparum or P.vivax reached 1 parasite/μl, and the tested blood samples of non-malaria fever patients, patients with other infectious diseases and healthy persons were all negative. Consistent results of each sample in more than 3 duplicated tests were obtained. Conclusion The optimized Tag?鄄primer nested/multiplex PCR shows high sensitivity, specificity and stability in malaria diagnosis.

Study on Immuno-effect with GRA4 or SAG2 Gene Recombinant BCG Vaccine of Toxoplasma gondii

LIJun-hua;WUShao-ting;WENGYa-biao;GANYan;LIUHong-bo;LIUMao-ling;ZHANGRen-li;GAOShi-tong;HUANGDa-na;GENGYi-jie

2007, 25(3):  14-221. 

Asbtract ( )   PDF (247KB) ( )  

Related Articles | Metrics

【Abstract】 Objective To compare the immuno-protection induced by the recombinant BCG vaccine of Toxoplasma gondii GRA4 gene （rBCG-GRA4） and SAG2 gene （rBCG-SAG2） in BALB/c mice. Methods 108 SPF BALB/c mice were divided into 6 groups： PBS， BCG， rBCG， rBCG-GRA4， rBCG-SAG2 and rBCG-GRA4+SAG2， each with 18 mice. Each mouse was injected by 100 μl corresponding materials for 2 times. Blood was taken from tail vein before inoculation. 4，6 and 8 weeks after inoculation， spleen was moved and blood was taken from orbit vein of 3 mice from each group for the detection of cytokines， IgG and IgM antibodies， T lymphocyte subgroups and transformation efficiency. 3 weeks after the last inoculation， 9 mice from each group were challenged intraperitoneally with 50 tachyzoites of T.gondii RH strain and their survival time was observed. Results rBCG vaccine of T.gondii induced immune response. The value of CD3⁺CD4⁺/CD3⁺CD8⁺ of group BCG-GRA4+SAG2 was the highest （14.06±1.17） in the 4th week; the IgG titer in the BCG-GRA4+SAG2 group was the highest （0.18±0.02） in the 6th week and the IgM titer in the BCG-SAG2 group was the highest （0.82±0.05） in the 8th week. The average survival time of the mice in BCG-SAG2 group was about 8.61 days after challenged with tachyzoites， and that of the PBS control group， 7.33 days. The average survival time in the 3 immunized groups was one day longer than that of the control. Conclusion The rBCG vaccine of T.gondii shows certain immuno-protection in mice.

Study on 5S rDNA Sequence of Two Isolates of Trichinella from Guangxi

YANGYi-chao;LIXue-ming;OU-YANGYi;XIEZu-ying

2007, 25(3):  15-224. 

Asbtract ( )   PDF (183KB) ( )  

Related Articles | Metrics

【Abstract】 Objective To analyze 5S ribosomal DNA （5S rDNA） sequences of two Trichinella isolates from Guangxi. Methods The fragments of 5S rDNA were obtained by PCR from the isolates of Debao and Nandan， and sequencing was made for the PCR products. Homogeneity， genetic distance matrix and phylogenetic tree were analyzed by related software. 5S rDNA sequences of the two isolates were compared separately with those of Trichinella species in GenBank. Results 5S rDNA sequences of three Trichinella isolates （Debao， Nandan and T.spiralis） showed the same length at 695 bp. There were 4 variable positions. The homogeneities of Debao and Nandan isolates with T.spiralis were 99.0% and 99.1% respectively. The homogeneities between Debao isolate and Nandan isolate was 98.8%. Compared with other Trichinella isolates in GenBank， they were all less than 94.2%. The evolutionary distance among isolates of Debao and Nandan and T.spiralis was 0.014. Meanwhile， the evolutionary distances between the Guangxi isolates and other Trichinella isolates in GenBank were more than 0.056. Phylogenetic tree analysis revealed that two isolates of Guangxi and T.spiralis located at the same node， revealing a close relationship. Bootstrap confidence values in two phylogenetic trees were 96 and 99， respectively. Conclusion The two Trichinella isolates of Guangxi show a high homogeneity with T.spiralis，locate at the same nodes in phylogenetic tree，suggesting that the Debao and Nandan Trichinella isolates be identified as T.spiralis.

现场研究

Factors Affecting Malaria Outbreak in Congjiang County of Guizhou Province

SHENGHui-feng;ZHENGXiang;SHIWen-qi;XUJian-jun;JIANGWei-kang;WANGDuo-quan;TANGLin-hua

2007, 25(3):  16-229. 

Asbtract ( )   PDF (285KB) ( )  

Related Articles | Metrics

【Abstract】 Objective To make a field investigation on the affecting factors of malaria outbreak in a village of Congjiang County, Guizhou Province. Methods The investigation was made in August， 2006. Filter paper dry blood samples were taken for indirect fluorescent antibody test (IFAT) from all the 495 residents above 1 year-old in the village where an outbreak of malaria was reported. Questionnairing was conducted in 423 villagers over 10 years-old, covering malaria history in the past 2 years, knowledge on malaria and its control, use of mosquito nets, and out-door sleeping habit. Data on febrile outpatients were collected from the records of the township health center for analyzing the compliance of the patients in seeking medical services. Mosquito collecting by human-bait before mid-night, and in mosquito nets and cattle pens in early morning was performed for mosquito composition and man-biting rate. Results Re-examination of the 42 positive blood smears confirmed 12 positives of P.vivax infection. The malaria incidence in 18 d was 2.1%，including 4 cases clinically diagnosed. The antibody positive rate of IFAT in the population was 8.7% (43/495) with a positive GMRT of 20.6, overall GMRT of 10.6; the IFAT positive rate in the age group of under 5 was 7.5% (3/40) with a GMRT of 25.1. The rate of seeking medical advice among febrile patients was 81.3% (118/145), 78.8% (93/118) of which being in the village clinic. The average time of going to a doctor after fever was 3.9 days, 37.4% (195/521) and 3.3% (17/521) were in 4-6 days and over 10 days respectively， with the longest 26 days. The average knowledge rate on malaria was 25.5% (108/423), with 17.1%, 29.2% and 40.0% in the groups of illiteracy, primary school and high school education respectively. A statistical significance was found between primary school/high school education and the illiteracy （P＜0.01）. The average rate of using mosquito nets was 31.0% (131/423), out-door sleeping rate was40.7% (172/423). The radical cure rate in 2004 and 2005 was 68.2% (15/22) and 48.3% (14/29) respectively. In addition to Anopheles sinensis, An. anthropophagus and An. minimus also existed in rooms and nets with a man-biting rate of 0.0566 and 0.0755 respectively. Conclusions Three species of anopheline mosquitoes are the important transmitting vectors. Poor self-protection, outdoor sleeping habit, delayed examination and treatment, and irregular chemotherapy among the residents are the main factors resulting malaria outbreak.

Study on the Feasibility for ARIMA Model Application to Predict Malaria Incidence in an Unstable Malaria Area

ZHUJi-min;TANGLin-hua;ZHOUShui-sen;HUANGFang

2007, 25(3):  17-236. 

Asbtract ( )   PDF (283KB) ( )  

Related Articles | Metrics

【Abstract】 Objective To explore the application of seasonal time series ARIMA model in prediction of malaria incidence in an unstable malaria area. Methods SPSS13.0 software was used to construct the ARIMA model based on the monthly malaria incidence of Huaiyuan and Tongbai counties in Huaihe River Valley， from Jan. 1998 to Dec. 2005, with consideration of residual uncorrelation and concision. Akaike′s information criterion （AIC） and Bayesian information criterion （BIC） were used to confirm the fitness of model. The constructed model was then applied to predict the monthly malaria incidence in 2006 and the incidence from ARIMA model was compared with the actual incidence， so as to evaluate the model′s validity. Malaria incidence of 2007 was predicted by ARIMA model based on malaria incidence from 1998 to 2006. Results Statistics assisted estimation of the significance of the fitted autoregressive and seasonal moving average coefficients （AR1=0.512， SMA1=0.609， P<0.01）. ARIMA（1，0，0）（0，1，1）12 model， with AIC=67.01， BIC=71.87 and white noise for predicting error， exactly fitted the incidence of the previous monthly incidence from Jan. 1998 to Dec. 2005， and the predicted monthly incidence in 2006 by the model was consistent with the actual incidence. Malaria incidence of 2007 would be 106.50/100 000， with a peak incidence during July and October. Conclusion The model of ARIMA seems to be an appropriate model to fit exactly the changes of malaria incidence and to predict the future incidence trend, with a high prediction precision of short term time series.

综述

Application of Reverse Vaccinology in Schistosoma Vaccine Development：Advances and Prospects

FENGXin-gang;SUIChuan-yu;YUANChun-xiu;SHAODong-hua;CHENJin-xin;LINJiao-jiao

2007, 25(3):  18-247. 

Asbtract ( )   PDF (395KB) ( )  

Related Articles | Metrics

【Abstract】 Objective Current advances in reverse vaccinology based on the principle of “sequence-structure-function” and such integrated platform technologies as immunoinformatics， computeraid design， and various high-throughput omics （including genomics， transcriptomics and proteomics） may pave a new way for the discovery of candidate vaccine molecules against schistosomiasis. Both theoretical prediction and experimental approaches conventionally used in the field of reverse vaccinology are briefly introduced in this review; and the applications of these approaches to screening and confirming candidate Schistosoma vaccine molecules are also summarized. Furthermore， potential research prospects of the application of reverse vaccinology to Schistosoma vaccine development are discussed by simulating immune effect mechanisms of immunization with radiation-attenuated cercaria vaccine in animal hosts and naturally acquired immunity in human population.

信息报道

An Analysis on Papers Published by the National Institute of Parasitic Diseases in 2002-2006

ZHANGMin-qi

2007, 25(3):  19-250. 

Asbtract ( )   PDF (211KB) ( )  

Related Articles | Metrics

【Abstract】 Objective To partially evaluate the scientific and technological activities of the Institute of Parasitic Diseases， China CDC， through publication analysis. Methods Information on the papers published in the last 5 years was collected since the renaming of the Institute in 2002. Number， category and being cited frequency of the publications were analyzed using the data of 2002 as baseline. Results 272 papers were published at 48 national and international periodicals during 2002-2006. The total number， the number of papers published at the core journals and at the SCI journals all increased in the year 2003-2006. Publications on research， review and report occupied 54.8%， 36.0% and 15.4% respectively， covered schistosomiasis， malaria， echinococcosis， filariasis， visceral leishmaniasis， food-borne and soil-transmitted parasitic infections， and newly emerging parasites with 44.5% and 15.4% on schistosomiasis and malaria respectively. 87.9%， 11.0% and 1.1% of the articles were published at the national， international and local journals respectively. The balance rate for the trends of papers submitted in 2002 was 6.5%， and 10.2%-15.4% in 2003-2006. 34 of the 272 papers were included in SCI journals. Retrieval through the web of knowledge revealed that 187 citations were found in the SCI papers with an average of 5.5; 6 papers were cited for more than 9 times each， occupying 27.3% of the overall citations， the highest being 84 citations. There was an unbalanced distribution of the publications among the departments of the Institute. Conclusion The results indicate that the research direction and content are in line with the tasks of the Institute and with the scientific merits of disease control; the level of research is increasing and some of the publications exert certain impact at home and abroad.

研究简报

An Epidemiological Survey on Echinococcosis in Zhiduo County of Qinghai Province

WUXian-hong;WANGHu;ZHANGJing-xiao;MAXiao;LIUYu-fang;HANXiu-min;LIUHai-qing;CAIHui-xia;ZHAOYan-mei;MAJun-ying;LIUPei-yun;ZENGCheng

2007, 25(3):  20-231. 

Asbtract ( )   PDF (215KB) ( )  

Related Articles | Metrics

【Abstract】 The survey was carried out in July， 2006 in Zhiduo County. The IHA and ELISA positive rate in human population was 4.5% （42/933） and 8.2% （76/931） respectively. Ultrasonography revealed a morbidity of 3.4% （33/979） with 3.2% Echinococcus granulosus and 0.2% of E.multilocularis respectively. Animal dissection showed an infection rate of 15.1% （14/93） in pikas with one infected by E.shiquicus proved by molecular biology. Coproantigen rate by ELISA was 6.2% （12/193） in dogs and 35.7% （5/14） in wolves. The results indicated that Zhiduo County is a mixed endemic area for echinococcosis.

Construction of Eukaryotic Expression Plasmids with Paramyosin Gene of Periodic Brugia malayi

CHENYang, FANGZheng, HUANGWei-qun, XIEDong-fang, JIANGSheng-yang, WUJian-jun

2007, 25(3):  21-252. 

Asbtract ( )   PDF (215KB) ( )  

Related Articles | Metrics

【Abstract】 Total RNA was extracted from periodic Brugia malayi. Specific primers were designed on the basis of known sequences of paramyosin gene from B.malayi （BmPmy）. The desired gene was amplified by PCR technique from cDNA. The PCR products were purified and cloned into plasmid pGEM-T by T-A cloning method， transformed into Escherichia coli （E.coli） strain DH5α. The recombinant plasmids were screened and identified by digestion with restriction enzyme and PCR amplification. The right gene fragments encoding BmPmy in positive clones for prokaryotic and eukaryotic expression plasmids were digested with restrictive endonuclease， and were subcloned into pcDNA3.1（+）. The recombinant eukaryotic plasmid （pcDNA3.1-BmPmy） was then transfected into COS-7 cells. The transient expression of BmPmy was examined with RT-PCR. BmPmy mRNA was highly expressed in transfected COS-7 cells.

研究简报

Comparative Study on Polytene Chromosomes of Two Isolates of Simulium quinquestriatum

WENXiao-jun;WEIJing;CHENHan-bing

2007, 25(3):  22-255. 

Asbtract ( )   PDF (221KB) ( )  

Related Articles | Metrics

【Abstract】 The salivary glands were exposed and isolated from the larvae of Simulium quinquestriatum and stained in carbol fuchsin, squashed between slide and coverslide. Slides were examined and photographed under microscope to measure the polytene chromosomes. Systematic analysis was made. Results indicated that the number of the polytene chromosomes of both isolates is three. The main characteristic chromosomal structures are homologized. Only the banding types of ⅡL are different.

Dot Enzyme-Linked Immunosorbent Assay for Detection of Serum Antibody to Blastocystis hominis in Humans

SUShui-lian;YANYi-ming;LIAOHua;CHENGui-feng;ZHANGRui-qi;XIEQiong-jun;LEXiao;HUYa-qiong;ZENGXue-ying;LANHai-ying;XIERui-lian;HuangZhen

2007, 25(3):  23-258. 

Asbtract ( )   PDF (251KB) ( )  

Related Articles | Metrics

【Abstract】 Serum and stool samples were collected from 322 undergraduate students in medical school. Using stool in vitro cultivation as golden standard， 178 cases were found Blastocystis hominis positive and 144 were negative. Dot-ELISA was used to examine the serum samples with a sensitivity of 92.1% （164/178） and specificity of 97.1% （141/144）. This revealed that dot-ELISA can be used for antibody detection against Blastocystis hominis.

Malaria Epidemic Situation in Jiangsu Province in 2006

WANGWei-ming;GaoQi;JINXiao-lin;ZHOUHua-yun

2007, 25(3):  25-封三. 

Asbtract ( )   PDF (170KB) ( )  

Related Articles | Metrics

【Abstract】 In 2006， there were 767 reported malaria cases in Jiangsu Province with an incidence of 1.07‰ and increased by 16.57% in comparison to the previous year. Positive rate of blood examination in local febrile patients was 0.08% （293/361 896） but 1.23% （251/204 40） in mobile population （P＜0.01）. Cases with relapses occupied 9.00% of the total. The density of Anopheles sinensis was 0.61 per net and increased by 110% more than the year 2005 （0.29/net）. It is indicated that the increase of A. sinensis density has been the main factor for malaria recurrence in the area north of Huaihe River in the Province.