Table of Content

30 August 2013, Volume 31 Issue 4

Previous Issue    Next Issue

Molecular Cloning and Characterization of a Novel Clonorchis sinensis Antigenic Protein Containing Tandem Repeat　Sequences

LIU Qian1，XU Xue-nian1 *，ZHOU Yan1，CHENG Na1，DONG Yu-ting1，ZHENG Hua-jun2，ZHU Yong-qiang2，FENG Zheng1

2013, 31(4):  1-245-250. 

Asbtract ( )   PDF (21891KB) ( )  

Related Articles | Metrics

Objective  To find  and clone new antigen genes from the λ-ZAP cDNA expression library of adult Clonorchis sinensis, and determine the immunological characteristics of the recombinant proteins.  Methods  The cDNA expression library of adult C. sinensis was screened by pooled sera of clonorchiasis patients. The sequences of the positive phage clones were compared with the sequences in EST database, and the full-length sequence of the gene（Cs22 gene） was obtained by RT-PCR. cDNA fragments containing 2 and 3 times tandem repeat sequences were generated by jumping PCR. The sequence encoding the mature peptide or the tandem repeat sequence was respectively cloned into the prokaryotic expression vector pET28a（＋）, and then transformed into E. coli Rosetta DE3 cells for expression. The recombinant proteins （rCs22-2r, rCs22-3r, rCs22M-2r, and rCs22M-3r） were purified by His-bind-resin（Ni-NTA） affinity chromatography. The immunogenicity of rCs22-2r and rCs22-3r was identified by ELISA. To evaluate the immunological diagnostic value of rCs22-2r and rCs22-3r, serum samples from 35 clonorchiasis patients, 31 healthy individuals, 15 schistosomiasis patients, 15 paragonimiasis westermani patients and 13 cysticercosis patients were examined by ELISA. To locate antigenic determinants, the pooled sera of clonorchiasis patients and healthy persons were analyzed for specific antibodies by ELISA with recombinant protein rCs22M-2r and rCs22M-3r containing the tandem repeat sequences.  Results  The full-length sequence of Cs22 antigen gene of C. sinensis was obtained. It contained 13 times tandem repeat sequences of EQQDGDEEGMGGDGGRGKEKGKVEGEDGAGEQKEQA. Bioinformatics analysis indicated that the protein（Cs22） belonged to GPI-anchored proteins family. The recombinant proteins rCs22-2r and rCs22-3r showed a certain level of immunogenicity. The positive rate by ELISA coated with the purified PrCs22-2r and PrCs22-3r for sera of clonorchiasis patients both were 45.7%（16/35）, and 3.2% （1/31） for those of healthy persons. There was no cross reaction with sera of schistosomiasis and cysticercosis patients. The cross reaction with sera of paragonimiasis westermani patients was 1/15. The recombinant proteins rCs22M-2r and rCs22M-3r which only contained tandem repeats were specifically recognized by pooled sera of clonorchiasis patients.  Conclusion  The Cs22 antigen gene of Clonorchis sinensis is obtained, and the recombinant proteins have certain diagnostic value. The antigenic determinant is located in tandem repeat sequences.

Enterobius vermicularis Infection Status among Children in 9 Provinces/Autonomous regions/Municipalities of China

CHEN Ying-dan, WANG Ju-jun, ZHU Hui-hui, ZHU Ting-jun, ZANG Wei, QIAN Men-bao, LI Hong-mei, ZHOU Chang-hai, WANG Guo-fei, XU Long-qi

2013, 31(4):  2-251-255. 

Asbtract ( )   PDF (17112KB) ( )  

Related Articles | Metrics

Objective  To investigate the infection status of Enterobius vermicularis among children in 9 Provinces/Autonomous regions/Municipalities (P/A/M) of China, and analyze its risk factors.  Method  From April to December 2011, one provincial capital（prefecture-level city） and one county（city, district） were chosen as investigation spots from Guangdong, Guangxi, Hainan, Chongqing, Sichuan, Zhejiang, Fujian, Anhui and Guizhou, respectively. Children aged 2 to 12 were examined by using adhesive cellophane anal swab with round-bottom tube. Information of children's family condition, health behavior and school environment were collected by questionnairing.  Results  14 964 children were examined, and 14 582 qualified questionnaires were collected. The total prevalence was 17.8% （2 659/14 964）. Of the 9 P/A/M, the prevalence was highest in Hainan Province （51.1%, 869/1 701） and lowest in Anhui Province（0.8%, 13/1 589）. The prevalence in urban areas （7.3%, 552/7 581） was lower than that of  rural areas（28.5%, 2 107/7 383） （χ2=1156.73， P<0.01）. The highest prevalence in urban and rural areas was found in Haikou City（38.0%, 322/847） and Wanning City （64.1%, 547/854） of Hainan Province. The prevalence rate in males and females was 17.4% （1 410/8 128） and 18.3% （1 249/6 834）, respectively （χ2=2.192， P>0.05）. The highest prevalence in males （61.2%, 300/490） and females （67.9%, 247/364） was found in children of Wanning City. Multivariate logistic regression analysis showed that residence, education level of parents, occupation of parents, nail biting, types of classroom ground and type of boarding were the risk factors on E. vermicularis infection.  Conclusion  The prevalence of enterobiasis in children is still high in many areas of China, and the prevention and control measures should be taken according to the risk factors.

Tissue Localization and Expression Difference of Endogenous β-glucosidase in Digestive System of Musca domestica Third Instar Larvae

HU Rong, ZHANG Shu, WU Jian-Wei *, GUO Guo, FU Ping

2013, 31(4):  3-256-261. 

Asbtract ( )   PDF (25781KB) ( )  

Related Articles | Metrics

Objective  To study the tissue localization and expression difference of endogenous β-glucosidase in digestive system of Musca domestica third instar larvae.  Methods  The digestive system of the 3rd instar larvae of Musca domestic was taken for the below tests. Tissue localization of endogenous β-glucosidase mRNA was identified by in situ hybridization. Cellulase was localized by immunohistochemistry. The enzymatic activity of β-glucosidase was measured by 3, 5-dinitrosalicylic acid（DNS） assay. The relative mRNA expression levels of M. domestica β-glucosidase gene in these organs were determined by RT-PCR.  Results  β-glucosidase mRNA， with in situ hybridization， was shown in the epithelial cells of midgut, salivary glands and foregut of the larvae. The immunohistochemical analysis on larvae tissues revealed that cellulase was produced and secreted by the epithelial cells of the midgut, salivary glands and foregut. β-glucosidase activity in salivary glands, foregut, midgut, and hindgut was（0.80±0.06）, （0.38±0.02）, （1.20±0.05） and（0.26±0.02） IU/mg, respectively. There was significant difference in β-glucosidase activity among these digestive organs （P<0.05）. The activity level of β-glucosidase was highest in midgut ［（45.45±1.27）%］, and lowest in hindgut［（9.85±0.88）%］. However, β-glucosidase gene were only expressed in the salivary gland， foregut and midgut. Significant differences in gene expression level of β-glucosidase was found among these organs（P<0.05）. The relative expression quantity of β-glucosidase gene in midgut and salivary glands were 5 and 3 times higher than that in foregut.  Conclusion  The endogenous β-glucosidase gene is expressed in the foregut, midgut and salivary glands. The midgut and salivary glands of Musca domestica 3rd instar larvae are the primary organs of this enzyme secretion.

Genetic Variations of the Elastase Gene among Eight Populations of Schistosoma japonicum

SU Jing1，XU Bin2 *，LIU Xiu-feng1，YIN Ming-bo1，HU Wei1, 2

2013, 31(4):  4-264-269. 

Asbtract ( )   PDF (20187KB) ( )  

Related Articles | Metrics

Objective  To investigate genetic diversity in the elastase gene among eight Schistosoma japonicum populations, and whether natural selection occur.  Methods  S. japonicum populations were collected from the provinces of Anhui（Tongling and Guichi）, Hunan（Yueyang）, Hubei（Shashi）, Sichuan（Xichang）, Yunnan（Eryuan）, Taiwan （Puye） in China, and the Philippines. The elastase gene from different populations was amplified by PCR and then sequenced. Watterson’s θ, Tajima’s π, dN/dS ratio, Tajima’s D and fixation index（Fst） of each population were calculated. The phylogenetic networks based on the elastase gene were constructed by median-joining algorithm.  Results  A total of 73 elestase gene sequences（GenBank No. KF297654-KF297681）were obtained from 8 populations. The sequence analysis indicated that higher genetic diversity was found in the populations from the middle and lower reaches of the Yangtze River（i.e. Tongling City of Anhui, Yueyang City of Hunan）, while there was no genetic variations in Hubei or Philippines populations. The value of Tajima’s D was positive in Hunan population, while negative in the other populations. The dN/dS ratio was higher than 1 in Tongling population, whereas lower than 1 in Taiwan population. Significant genetic differentiations were observed between Taiwan population and other populations.  Conclusion   The genetic diversity of the elastase gene among S. japonicum populations is very high, and a high level of gene flow has been detected among the populations from the middle and lower reaches of the Yangtze River. The S. japonicum elastase gene might have been under a positive selection. The level of genetic divergence is the highest between Taiwan population and others.

Screening and Evaluation of Schistosoma japonicum SjRibosomal_L18a Protein and its B Cell Epitopes

WEI Gang-gang1, XU Bin2, JU Chuan2, HU Wei1,2 *

2013, 31(4):  5-270-274. 

Asbtract ( )   PDF (19202KB) ( )  

Related Articles | Metrics

Objective  To screen a ribosomal protein（SjRibosomal_L18a） of Schistosoma japonicum and predict its B cell epitopes, and evaluate the potential diagnostic value of the recombinant protein and the synthetic B cell epitopes.  Method  S. japonicum protein sequences were screened and analyzed by using B-cell epitope prediction softwares. The immunogenic protein was selected based on the predicted score and the quantity of epitopes. The epitopes with higher score（P1 and P2） were synthesized. The relative molecular mass（Mr）, isoelectric point, grand average of hydropathicity, signal peptide, and transmembrane domain were predicted by bioinformatics tools. RT-PCR was used to analyze the transcription level of the different development stages. The encoding sequence was amplified by PCR, and cloned into pET28a vector. The recombinant plasmid was transformed into in E. coli BL21（DE3） cells and induced with IPTG. The recombinant SjRibosomal_L18a protein was purified with Ni-NTA resin. ELISA was used to evaluate the potential diagnostic value of the recombined protein and the synthetic B cell epitopes.  Results  SjRibosomal_L18a protein was obtained, its B cell epitopes and physicochemical properties were predicted. The open reading frame of SjRibosomal_L18a was composed of 531 bp, and encoded a 176-amino-acid protein with Mr 20 741, pI 11.12. RT-PCR result showed that this gene was transcribed at high level in each developmental stage. The recombinant plasmid SjRibosomal_L18a/pET-28a was constructed and the protein was expressed as inclusion bodies （Mr 26 069）. The sensitivity and specificity of recombined protein, P1 and P2 were 53.3% （8/15） and 100% （15/15）, 60% （9/15） and 100% （15/15）, 73.3% （11/15） and 100% （15/15）, respectively.  Conclusion  The recombinant protein（SjRibosomal_L18a） and its epitopes with higher immunogenicity are obtained. The sensitivity of the two epitopes （P1 and P2） was higher than that of SjRibosomal_L18a protein.

Protective Effect of Radix Sophorae Flavescentis Mixture on Intestinal Mucosa in Mice Infected with Cryptosporidium parvum

JI Rui，CUI Wei*，LIANG Rui-wen，GUAN Zhi-yu，LI Rui-fang

2013, 31(4):  6-275-279. 

Asbtract ( )   PDF (18273KB) ( )  

Related Articles | Metrics

Objective  To investigate the protective effect of radix sophorae flavescentis（RSF） mixture on intestinal mucosa in mice infected with Cryptosporidium parvum.  Methods  Thirty BALB/c male mice were randomly divided into control group, infection group and RSF mixture treatment group. Mice of the posterior two groups were inoculated intragastrically with 1×105 C. parvum oocysts, immunosuppressed with dexamethasone（5 ug/ml） and gentamycin sulfate（40 ug/ml） in drinking water. At the 8th day post-infection, mice in RSF mixture treatment group were treated with 0.2 ml dose of RSF mixture twice a week（three-day intervals）for three weeks. The mice in infection group and RSF mixture treatment group were monitored for oocyst shedding in fecal pellets every two days after treatment. At 28 days after infection, experimental mice were sacrificed, jejunal tissue was removed for preparation of paraffin-embedded sections. The changes of CD3+, CD4+, CD8+ T lymphocytes and IgA plasmocytes in intestinal mucosa were determined by immunohistochemistry. In addition, jejunums of infected mice and treated mice were collected, and ultrastructural changes were observed under electron microscopy.  Results  Compared with infection group, the level of oocyst shedding was obviously lower and the time of the oocyst discharging was significantly shorter in RSF mixture treatment group. The proportion of CD3+, CD4+ T lymphocyte and CD4+/CD8+ T cell ratio in infection group（49.7%±2.4%, 25.7%±2.2%, 1.1±0.3）were significantly lower than that of treatment group（62.4%±1.4%, 37.5%±3.1%, 1.5±0.3）and control group（66.5%±1.9%, 40.1%±1.8%, 1.5±0.2）（P<0.01）. CD8+ T lymphocytes showed no significant difference in each group（P>0.05）. The number of IgA plasmocytes in treatment group（52.7±3.5） was significantly higher than that of control group （8.3±2.3） and infection group （33.7±2.6）（P<0.01）. After administration for three weeks, the damaged C. parvum parasites were seldom seen in mouse jejunum, and lysosomes appeared in large number, RSF mixture treatment improved mitochondrial structure and repaired microvilli. In infection group, mitochondria ridges were significantly broken and microvilli surrounding C. parvum oocysts were shed, resulting in the appearance of crater-like lesions on the surface, the oocyst wall and host cell membrane fused together.  Conclusion  RSF mixture is effective against Cryptosporidium parvum. The damage of intestinal mucosa in infected mice can be repaired after treatment.

Effect of Toxoplasma gondii Infection on Thymus Cells in Rats

LIU Hua1 *，LI Hua-guang2，GENG Dan-dan3，SUN Li1，WANG Jun2，LIU Su2

2013, 31(4):  7-280-283. 

Asbtract ( )   PDF (18777KB) ( )  

Related Articles | Metrics

Objective  To study the pathological damage of thymus and thymus cell apoptosis of male rats infected with Toxoplasma gondii.  Methods  Fifty Wistar male rats（7-8-week-old） were randomly divided into infection group（40） and control group（10）. Rats in infection group were infected with 5×104 tachyzoites by intraperitoneal injection, while those in control group received same volume of PBS. On the 3rd, 6th, 9th and 12th day post infection, ten rats from infection group and two from control group were sacrificed, the thymus glands were removed. The thymus tissue sections were stained with hematoxylin and eosin（HE） for observation on histopathological changes. Single thymus cell suspensions were prepared. Cell cycle analysis was performed by flow cytometry, and proliferation index was calculated. Thymus frozen sections were stained with Hoechst 33258, and morphologic changes in apoptotic nuclei were observed under fluorescence microscope. Expression of Bcl-2 and Bax proteins were determined by using immunohistochemistry.  Results  Microscopic examination showed that pathological changes occurred in thymus grand on the 3rd day after infection. The space between connective tissue capsules was widened, cells in cortex and medulla cells were sparse, and more phagocytes and extravasated blood were found in thymus. On the 6th day post infection the thymus damage was aggravated, and no significant improvement was seen on day 12. On the 3rd, 6th, 9th and 12th day after infection, thymocyte proliferation index was （11.15±0.99）%, （6.17±1.02）%, （5.45±0.96）% and （6.63±1.52）%, respectively, and each of them was significantly lower than that of the control ［（13.81±1.18）%］（P<0.01）. On the 3rd day after infection, the number of apoptotic cells increased, significantly increased on day 6, and there was no much difference in the number of apoptotic cells between day 6 and day 12. The immunohistochemistry results showed that on the 3rd, 6th, 9th and 12th day post-infection, the gray scale value of Bax positive cells was 88.21±4.74, 64.69±6.82, 83.62±5.79, and 101.09±6.72, respectively, and each of them was significantly lower than that of the control （128.69±8.95）（P<0.01）, while there was no significant change in the Bcl-2 protein level （P>0.05）.  Conclusion  T. gondii causes severe pathological damage in host thymus tissue with a decrease in the proliferation index, an increase in the number of apoptotic cells, and high expression of Bax protein.

Evaluation on the Immune Response Induced by DNA Vaccine Encoding MIC8 Co-Immunized with IL-12 Genetic Adjuvant against Toxoplasma gondii Infection

ZHAO Huan-ge, HUANG Feng-ying, GUO Jun-li, TAN Guang-hong*

2013, 31(4):  8-284-289. 

Asbtract ( )   PDF (26501KB) ( )  

Related Articles | Metrics

Objective  To examine the immunoprotection effect induced by MIC8 DNA vaccine co-immunized with a plasmid encoding murine IL-12（pcIL-12） as an adjuvant in mice against the challenge of Toxoplasma gondii.  Methods The gene sequence encoding MIC8 of T. gondii RH strain was inserted into eukaryotic expression vector pcDNA3.1 to construct the pcMIC8 expression plasmid. The recombinant plasmid was transfected into HeLa cells to test its expression and the recombinant protein was then characterized by Western blotting. Eighty Kunming mice were randomly divided into 5 groups（16 per group）: 3 control groups（PBS, pcDNA3.1, and pcIL-12）, pcMIC8 group, and pcMIC8 plus pcIL-12 group. Mice in the pcMIC8 plus pcIL-12 group were co-injected intramuscularly at a dosage of 100 μl each of pcMIC8 and pcIL-12 suspended in 100 μg sterile PBS. Mice in other groups were inoculated with PBS, pcDNA3.1, pcIL-12, and pcMIC8 respectively following the same protocol. All the mice received three immunizations at 2-week intervals. Serum samples were collected on day 0, 13, 27, 41, and 55 before each inoculation for determining antibody IgG, IgG subclass IgG2a. Four weeks after the final immunization, IFN?-γ and IL-4 levels in splenocytes cultures from immunized mice were detected by ELISA. The mice were challenged with 103 tachyzoites of the virulent T. gondii RH strain three weeks after the last immunization to observe the survival time.  Results  Western blotting showed that the protein extracts in HeLa cells upon transfection with pcMIC8 were effectively expressed in cells. The levels of IgG（0.51±0.028） and IgG2a（0.261±0.04）(on day 55) in mice immunized with pcMIC8 plus pcIL-12 were higher than pcMIC8 group(497.65±98.15) and control groups (PBS 47.18±2.73， pcDNA3.1 50.08±4.62， pcIL-12 118.15±12.73）（P<0.05）. There was no significant difference in the level of IgG 1 and IL-4 among the five groups（P>0.05）. After a lethal challenge of T. gondii RH strain, the survival time in mice immunized with pcMIC8 plus pcIL-12（15 d） was prolonged in comparison to that of pcMIC8（10 d） and control groups（PBS 5 d， pcDNA3.1 6 d， pcIL-12 8 d）（P<0.05）.  Conclusion  The immune responses induced by the combined use of the recombinant plasmid encoding MIC8 of T. gondii with murine IL-2 gene adjuvant can be enhanced.

Cloning and Prokaryotic Expression of Casein Kinase Ⅱ Subunit Beta Gene Fragment of Dirofilaria immitis

GAO Jun-shan，WU Wei, HOU Hong-lie, GONG Peng-tao, LI Jian-hua, LI He,

2013, 31(4):  9-290-292. 

Asbtract ( )   PDF (11027KB) ( )  

Related Articles | Metrics

 Objective  To clone and express the partial fragment of Csnk2b gene of Dirofilaria immitis in prokaryotic cells, and analyze the immunoreactivity.  Methods  The partial fragment of Csnk2b gene was amplified by PCR with a pair of specific primers. The PCR product was cloned into pMD18-T, and then sub-cloned to pGEX-4T-1 expression vector. The constructed plasmid pGEX-4T-1-Csnk2b was transformed into E. coli Rosetta（DE3） and followed by expression of the protein induced by IPTG. The recombinant protein was analyzed by SDS-PAGE and identified by Western blotting.  Results  The PCR product was about 700 bp. Enzyme digestion and DNA sequencing confirmed that the recombinant plasmid pGEX-4T-1-Csnk2b was constructed. SDS-PAGE results showed that the relative molecular weight （Mr） of the fusion protein（GST-Csnk2b） was about 45 000. GST-Csnk2b reacted positively with mouse anti-D. immitis serum.  Conclusion  The partial Csnk2b gene has been expressed in prokaryotic expression system and shows immunoreactivity.

Biological Safety of Aspergillus fumigatus SL-30 to Non-target Organisms

GUO Dan-zhao, CHEN Jun*

2013, 31(4):  10-293-297. 

Asbtract ( )   PDF (17173KB) ( )  

Related Articles | Metrics

Objective  To evaluate biological safety of Aspergillus fumigatus SL-30, a potential molluscicide, to non-target organisms.  Methods  A. fumigatus SL-30 spores were scattered in the water (200 ml) from Yangtze River, lake, rain and tap water to forming 6×106 cfu/ml, the number of spores were then determined and recorded every 2 days. Effect of A. fumigatus SL-30 spores with concentration ranging from 104 cfu/ml to 106 cfu/ml on Brachydanio rerio, Macrobrachium nippoensis and tadpoles of Rana limnochris was tested by standard laboratory procedure, and survival rate of the above animals in 30 days was recorded. The tests included acute oral toxicity in mice, acute dermal toxicity and acute inhalation toxicity in rats.  Results  Spores of A. fumigatus SL-30 can survive for about 12 days in each water samples. Under the spore concentration of 104 cfu/ml, 105 cfu/ml and 106 cfu/ml, there was no significant dose-dependent relationship between spore concentration and survival rate of experiment animals. No significant difference in survival rate was found between the three kinds of aquatic organisms treated with A. fumigatus SL-30 and de-chlorinous water（P＞0.05）. According to the experiment results of acute oral toxicity, acute dermal toxicity and acute inhalation toxicity, the acute toxicity of A. fumigatus SL-30 on animal was low. And the animals in experiment group did not show any obvious poisoning symptoms, anatomical abnormalities and pathologic change of the tissues.  Conclusion  Aspergillus fumigatus SL-30 is comparatively safe to environment and tested non-target organisms.

Dynamic Changes in Professional and Non-Professional Antigen Presenting Cells in the Spleen from Mice Infected with Schistosoma japonicum

MA Yi-lei, CONG Li, YIN Lan, CHEN Xiao-ping*

2013, 31(4):  11-298-302. 

Asbtract ( )   PDF (1109KB) ( )  

Related Articles | Metrics

Objective  To observe the changes in various dendritic cell （DC） subsets, macrophages, basophils, eosinophils and mast cells in mouse spleen before and after Schistosoma japonicum infection induced Th2 response.  Methods  C57BL/6 mice were infected with 20 S. japonicum cercariae via abdominal skin. Before infection and at 2, 4, and 6 weeks post-infection, the mice were sacrificed and spleen was removed. The frequencies of non-T, non-B basophils （NTNB）, eosinophils, mast cells, subsets of DC and macrophages in the spleen were measured by flow cytometry.  Results   At 4 weeks after infection, when Th2 cells started to occur, the proportion of CD11c+CD8+DC and CD11c+CD4+DC in B220-CD11c+DC increased from 7.4% and 7.9% before infection to 17.1% and 12.0%, respectively. During the infection, CD11c+CD4-CD8-DC, the majority of B220-CD11c+DC, remained on a nearly constant level（70%）; the percentage of B220+CD11c+ DC in NTNB decreased. The macrophages were subdivided into two subsets: F4/80+CD11bint and F4/80+CD11bhigh. The percentage of F4/80+CD11bint and F4/80＋CD11bhigh in NTNB dropped from 15.4% and 13.7% before infection to 2.7% and 8.6% at 4 weeks post-infection. The proportion of CD11b high macrophages in F4/80+ cells significantly increased from 47.1% before infection to 75.5% at 4 weeks after infection. During S. japonicum infection, eosinophil percentage in the spleen gradually increased, while the frequency of basophils and mast cells in NTNB greatly decreased.  Conclusion  At the time when Th2 response starts to occur, the frequency of CD11c+CD8+DC and CD11c+CD4+DC in CD11c+ dendritic cells increases. Once Th2 immune response established, the eosinophil frequency increases.

Investigation of Chigger Mites on Small Mammals in a Flatland Area of Menghan, Xishuangbanna, Yunnan Province

WANG Qiao-hua1,2, SHI Ai-min1 *, GUO Xian-guo2, SONG Wen-yu2, ZHAO Nan2, DONG Wen-ge2

2013, 31(4):  12-303-306. 

Asbtract ( )   PDF (13634KB) ( )  

Related Articles | Metrics

Objective  To investigate the species composition and distribution of chigger mites on small mammals in flatland area in Menghan, Xishuangbanna of Yunnan Province.  Methods  The field investigation was made in a flatland area near Lancangjiang River in Menghan, Xishuangbanna of Yunnan Province. Small mammals were captured with mouse cages and traps. All mites on the hosts were collected and preserved in 70% ethanol. Hoyer′s solution was used to mount the chiggers on glass slides. The specimens of the chigger mites on the slides were finally identified into species under microscope. The constituent ratio, infestation rate, mean abundance and mean intensity of chigger mites in different habitats or on different hosts were used to measure the community structure. The species richness and community diversity were analyzed.  Results  A total of 233 small mammal hosts were captured （belonging to 2 families, 3 genera and 5 species）. 5 763 individuals of chigger mites were identified as 2 subfamilies, 7 genera, and 45 species. Rattus tanezumi （R. flavipectus） was the dominant species among the captured hosts, accounting for 97.4% （227/233）. The mite infestation rate, average ectoparasite abundance, and mean mite intensity on R. tanezumi was 56.4% （128/227）, 24.7 （5 600/227） and 43.8（5 600/128）, respectively. Leptotrombidium deliense was dominant chigger mite species and account for 57.9% （3 337/5 763）, mainly infested R. tanezumi. Compared with indoor and cultivated field habitats, the species richness and community diversity of chigger mites in shrub habitat were higher, and 41 species of chigger mites were collected.  Conclusion  The species composition and community structure is relatively simple in the flatland area in Xishuangbanna. L. deliense is the most dominant species of chigger mites and its main host is R. tanezumi.

Influence Factors of Schistosoma japonum Infection among Fishermen in Eastern Dongting Lake Region

YU Xin-ling1，ZHOU Jie1*，HE Yong-kang1，HUANG Ming-zhu2，LI Yue-sheng1

2013, 31(4):  13-307-309. 

Asbtract ( )   PDF (10273KB) ( )  

Related Articles | Metrics

Objective  To investigate schistosome infection among the professional fishermen in Yueyang County, East Dongting Lake Region and its influence factors.  Methods  A total of 275 fishermen from two fisherman villages in Yueyang County were selected in 2009. They were investigated by fecal examination and questionnairing. The stool-egg positive individuals were detected by B ultrasound. The multivariate unconditional Logistic regression analysis was used to explore the related factors of schistosome infection and liver in fishermen.  Results  The total infection rate in fishermen was 40.4%（111/275）, and the geometric mean of EPG was 17.4±4.4. B ultrasound data showed among 111 egg positive individuals, 39（35.1%） cases manifested as hepatomegaly, 22（19.8%） had splenomegaly, 11（9.9%） had portal vein expansion and 65（58.6%） had hepatic fibrosis. Multivariate unconditional Logistic regression analysis showed that age groups（OR=0.630）, fishing working years（OR=2.470）, chemotherapy frequency（OR=0.425） and chemotherapy in 2008（OR=0.290） were the influence factors on schistosome infection（P<0.01）.  Conclusion  Schistosome infection rate is high, Schistosoma japonicum-induced liver and spleen injuries are still severe in fisherman of Eastern Dongting Lake Region.

Prospect on the Investigation of Sandflies (Diptera ∶ Psychodidae)in China

GUAN Li-ren

2013, 31(4):  14-310-314. 

Asbtract ( )   PDF (18496KB) ( )  

Related Articles | Metrics

Through literature review of the investigations on relevant sandflies(Dipter∶ Psychodidae) and his personal practical experience over the years, the author raises 5 issues referring to the taxonomy and biology of sandflies, density surveillance, transmisision of Leishmania parasites, and their distribution status which need to be further studied,  and the author looks forward to an attention from medical entomologists in China.

Research Advances in s48/45 Protein Family of Plasmodium falciparum

FAN Yan-ting1, 2, YOU Ping1, CHEN Jun-hu2 *

2013, 31(4):  15-315-318. 

Asbtract ( )   PDF (17163KB) ( )  

Related Articles | Metrics

The s48/45 domain is a β-sandwich fold domain, and usually includes 6-cysteines. Proteins containing s48/45 domain exist in each developmental stages of Plasmodium parasite, and play an important role in the invasion  into host cells. According to the features and functions of the protein molecule, members of the s48/45 protein family could be used as the vaccine candidates against Plasmodium falciparum in different stages. This article focuses on the research progress of P. falciparum protein family containing s48/45 domain.

Research Progress on Genotype and Genotype-associated Pathogenesis of Toxoplasma gondii

WANG Lin1,2, SHEN Ji-long2,3 *

2013, 31(4):  16-319-324. 

Asbtract ( )   PDF (25128KB) ( )  

Related Articles | Metrics

Toxoplasmosis is a disease caused by the protozoan Toxoplasma gondii, which is widely prevalent in animals and human throughout the world. It causes serious harm to human health and the development of animal husbandry. T. gondii isolates were considered a single species without geographical boundaries. However, high diversity has been revealed within and between T. gondii populations collected from around the world defined by the multi-locus enzyme electrophoresis（MLEE）, polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） or microsatellite analysis. Different strains of T. gondii may exhibit differences in virulence to mice. This paper summarizes the research progress on the genotypes from T. gondii isolates in different geographic regions around the world, and the relationship between genotype and virulence of T. gondii.

Investigation on Pinworm Infection and Relative Factors on Prevalence among Urban and Rural Preschool Children in Xianyang City

ZHAO Li-ping1，AN Rong1，SHI Xiao-ling1，WANG Li2，LI Yan-kui1

2013, 31(4):  17-261-263. 

Asbtract ( )   PDF (12778KB) ( )  

Related Articles | Metrics

A total of Eight hundred eighty-six children from 3 to 7 years old in 8 kindergartens were sampled in urban and rural area in Xianyang City from March to May 2012. The cellophane tape swab technique was used to examine pinworm eggs. Children’s hygiene habits, clinical symptoms and hygienic condition were surveyed by questionnairing. The total infection rate of pinworm was 11.2%（99/886）. The rate in males and females was 10.4%（52/500） and 12.2%（47/386）, respectively. The infection rate in rural kindergartens （19.1%, 70/367） was higher than that of urban kindergartens （5.6%, 29/519）（χ2=39.39，P＜0.01）. Among the investigated children aged 3-7 years, the infection rate in 4-5 years group （12.7%） was the highest, but no statistical difference was found among age groups（P>0.05）. Multivariate logistic regression analysis showed that the hygiene habits such as washing hands before eating（OR=0.180）, drinking unboiled water and eating non-cooked food（OR=2.473）,  cleaning perianal region frequently（OR=0.836）, cutting nails frequently（OR=0.450）, drying the quilt regularly（OR=0.224） and health education（OR=0.639） were the influence factors on pinworm infection. The main symptoms of pinworm infection include pruritus and bruxism.

Enhancement of in Vitro Protoscolicidal Effects of High-intensity Focused Ultrasound by a Superabsorbent Polymer and Ultrasound Contrast Agent

CAI Hui1,2，CHEN Lu-lu3，YE Bin1,2 *，ZHAO Hai-long4，LIU Ai-bo1,2，ZHANG Jing1,2，ZHAO Yi-feng5

2013, 31(4):  18-324-326. 

Asbtract ( )   PDF (12766KB) ( )  

Related Articles | Metrics

This study evaluated whether or not a superabsorbent polymer（SAP） combined with ultrasound contrast agent （UCA） could enhance damage efficacy of high intensity focused ultrasound（HIFU） on Echinococcus granulosus protoscoleces in vitro. Thirty test tubes each with 6 000-7 500 protoscolices were divided into 5 groups： group A （blank control） without HIFU treatment, group B treated with HIFU（50 W）only, group C treated with 10 μl UCA and HIFU, group D treated with 0.01 g SAP and HIFU, group E treated with 10 μl UCA, 0.01g SAP, and HIFU. In group B, echo enhancement of ultrasound image, suspension temperature（26.0 ℃±0.2 ℃） and protoscoleces mortality（30.4%） were higher than that of group A（18.0 ℃±0.1℃, 1.9%）（P<0.01）. Compared with group B, the echo enhancement of ultrasound image, suspension temperature（27.0 ℃±0.2 ℃, 28.2 ℃±0.2 ℃） and protoscoleces mortality（50.0%, 53.7%） of groups C and D increased significantly（P<0.01）. In group E, more protoscoleces were stained in red and their internal structures were indistinct. By chi-square test, the protoscoleces mortality of group E（69.7%） was higher than that of groups C and D （P<0.01）. There was no sinificant difference in suspension temperature among the 3 groups.    

Allergen Detection among 2 769 Children with Allergic Symptoms in Ningbo Area

LIU Wen-yuan1, 2，ZHOU Jiang-jin3

2013, 31(4):  19-327-328. 

Asbtract ( )   PDF (7405KB) ( )  

Related Articles | Metrics

A total of 2 769 children with allergic disease were admitted from October 2010 to December in Ningbo Women & Children′s Hospital. Fourteen kinds of serum specific-IgE were detected by immunoblotting method. Among the 2 769 children, the total positive rate of sIgE was 76.0%（2 105/2 769）. The sIgE positive rate in males （80.0%, 1 344/1 679） was significantly higher than that of females（69.8%, 761/1 090）（P<0.05）. The top three allergens were dust mites（33.2%）, milk（12.6%） and fungi（12.6%）. There were statistical differences of positive reaction to dust mites among 4 seasons（19.4%, 33.9%, 39.3%, 36.0%）（P<0.05）. Significant differences were found in the positive rates of dust mites, milk, fungi, and egg among the age groups（P<0.05）. The level of dust mite specific IgE were mainly in grade 3-6（613/918, 66.8%）.