Cystic echinococcosis (CE), caused by the larva of Echinococcus granulosus (Eg), is one of the key parasitic diseases to prevent and control in China. The Eg95 protein is a recognized vaccine candidate molecule, and the development of vector-mediated Eg95 vaccine is one of the current research hotspots in CE. This article summarizes the development status of Eg95 vaccine such as vaccinia virus, orf virus, goatpox virus, rabies virus, Salmonella typhimurium, Bacille Calmette-Guerin, Agrobacterium tumefaciens and Bifidobacteria bifidum, in order to provide valuable information for the immune prevention of CE.

Eimeria is the pathogen of chicken coccidiosis. Vaccine control is one of the hotspots of current study. Its surface antigen is an effective vaccine candidate molecule. This paper summarizes the development status of Eimeria surface antigen vaccine mediated by Bacille Calmettle-Guerinl (BCG), Lactococcus lactis (LL), Lactobacillus plantarum (LP), Salmonella typhimurium (St), Bacillus subtilis (Bs), Enterococcus faecalis (Efs), Escherichia coli (Ec), Cyanobacterium (Cb), Pichia, Leishmania tarentolae (Lt), viruses such as Fowlpox virus (FPV), Herpesvirus of turkey (HVT), Vaccinia virus (VV) and insect Buculovirus, in order to provide reference basis for development and application of new vaccines.

Vivax malaria caused by Plasmodium vivax (Pv) is one type of parasitic diseases seriously endangering human health,it recently becomes a hotspot to control this parasite by use of the vaccine.Pv merozoite surface protein 1,Pv circumsporozoite protein,Pv apical membrane antigen 1 and Pvs25 antigens are many types of candidate vaccine molecules.This review outlines the status in the research of vaccine of Plasmodium vivax mediated by bacteria such as Mycobacteria smegmatis,Agrobacterium tumefacies,and Pichiapastoris,and by viruses such as Adenovirus and Baculovirus.

Toxoplasmosis caused by Toxoplasma gondii is one type of zoonotic, parasitic diseases seriously endangering human health. Vaccine recently becomes the highlight in control of this parasite. ROPs antigen is an effective candidate molecule of vaccine. This review outlines the status in the research of ROPs vaccine of Toxoplasma gondii mediated by bacteria such as Lactococcus lactis, Mycobacteria smegmatis, Bacille calmette-Guerin, Agrobacterium tumefaciens and Pichia Pastoris, and viruses such as Canine adenovirus type 2, Adenovirus serotype 5, Feline herpesvirus type-1 and Vaccinia virus.

To investigate the weight reduction of hydatid cyst and level of splenocyte subsets in mice immunized with recombinant Bifidobacteria bifidum (Bb) Bb-Eg95-EgA31 vaccine of Echinococcus granulosus (Eg) and challenged with Eg protoscoleces,BALB/c mice were immunized with the vaccine subcutaneously,intramuscularly,intranasally or orally.Then the mice were challenged with 50 Eg protoscoleces on 8~(th) week after vaccination and killed on 25~(th) week after infection.The weight of hydatid cyst was measured and the reduction of the weight was calculated.The spleens were collected for splenocytes preparation.CD_4~+ and CD_8~+ T cells were determined by flow cytometry(FCM),and the blank vector,Bb or MRS were set as control.The hydatid cyst weight was reduced by 45.33%,41.33%,70.67% and 62.67% respectively for the 4 immunization groups.Number of CD_4~+ and CD_8~+ subsets in the immunization groups was more than that in the control group.CD_4~+ and the ratio of CD_4~+/CD_8~+ in the intranasal or oral immunization group was much higher than that in the subcutaneous or intramuscular immunization group.It's concluded that CD_4~+ and CD_8~+T cells may play an important role in the protection induced by recombinant Eg95-EgA31 vaccine of Eg.In addition,intranasal and oral vaccinations could be the better ways for immunization.

Objective To evaluate effect of the non-fused recombinant antigen in immuno diagnosis of echinococcosis. Methods The coding sequence of the target gene was cloned into prokaryotic non-fusion expression vector pQE30 ( + ) and expressed in E. coli. The recombinant protein was identified by SDS-PAGE and Western Blot, purified with affinity chromatography and used in ELISA to detect specific antibody in patients' sera. Results SDS-PAGE and Western blot demonstrated that Echinococcus multilocularis immunodominant major surface antigen gene was highly expressed in E. coli. The result of ELISA showed that out of 68 echinococcosis sera, 66 samples (97.1% ) were detected positively by the assay. Only 2 samples (2% ) were positive in 100 sera from cases with other infective diseases including cysticercosis or healthy persons. The sensitivity and specificity of the assay were 97.1% and 98% respectively. Conclusion Echinococcus multilocularis immunodominant major surface antigen gene has been highly expressed in E. coli in non-fusion form. ELISA with the recombinant protein is highly sensitive and genus-specific for echinococcosis diagnosis.

Objective　To construct a λgt11 cDNA expression library of Echinococcus multilocularis protoscolex isolated in China. Methods　Echinococcus multilocularis protoscolex mRNA was extracted using a Quickprep MicromRNA purification kit based on combining of the disruptive and protective properties of guanidinium thiocyanate (GTC) with the speed and selectivity of oligo (dT)-cellulose chromatography in a spum-column with some modification. Purified mRNA (1.8 μg) was submitted to reverse transcription using random hexamers ［pd(N6)］. The double-strand blunt-ended cDNAs were ligated with an EcoRI/NotI adaptor to form a cohesive EcoRI end. Subsequently the synthesized cDNA was inserted into vector λgt11 EcoRI arms. After being packaged in vitro, λgt11 was put to an infectious bacteria Echinococcus coli (E.coli) strain Y1090; the recombinants were screened by color selection. PCR amplification was performed to evaluate the size of insertion DNA fragments. Results　The recombinant ratio was nearly 100% and approximately 1×106 clones could be derived from this λgt11 cDNA library. PCR results indicated that the insertion DNAs were about 1.48 kb. Conclusions　A λgt11 cDNA expression library consisting of a million recombinant clones has been constructed from Echinococcus multicularis protoscolex mRNA. Further studies on this library are deserved.

The circumsporozoite protein(CSP) gene fragment of Plasmodium falciparum was cloned and sequenced.A pair of primer was designed according to the CSP encoding sequence of 837 isolate(Thailand isolate),and the CSP gene fragment was amplified by polymerase chain reaction(PCR) from Plasmodium falciparum FCC-1/HN isolate,it spanned the conserved region I.the central immunodominant repeat region\,the variable region behind the repeats and the conserved II region.After purification,the CSP gene fragment was digested with restriction enzyme BamH I and Kpn I,and ligated with the pBCG5.6 digested with the same enzyme.The recombinant pBCG5.6/CSP was transformed into E.coli DH5α.Positive clones were screened and identified by PCR technique and digestion with restriction enzyme.Nucleotide sequence was determined by dideotide chain-termination method.The results indicated that the CSP gene was successfully amplified and cloned,its nucleotide sequence was about 1 171 bp and was in accordance with the expected one.Sequence determination results showed that the cloned gene fragment was the same with the CSP encoding gene.

Objective To identify the best cell line for Pneumocystis carinii(Pc) proliferation Methods Specimens containing 5?10 5 Pc cysts were inoculated onto 8 kinds of cell lines separately. At the same time, Pc were inoculated in different amounts on HepG-2 cell line to identify the most suitable number of Pc needed for Pc proliferation in vitro within seven days. Results On HepG-2 cell line, Pc increased by 7-fold in trophozoite forms with a peak increasing rate between 4～5 days with the optimal growth at the cyst number of 5?10 5 .Conclusions HepG-2 cell line is found to be the most suitable cell line for Pc culture and the best inoculation number of Pc is 5?10 5.

Specific antigens of Echinococcus multilocularis is essential for the diagnosis of alveolar echinococcosis and vaccine development.Because of the limited source of nature antigen,its application is restricted.The development of recombinant antigens can provide large amount of antigen under effective quality control.This review summarizes the recent progress in antigen research,especially the recombinant antigen used for diagnosis of the disease.