OBJECTIVETo evaluate the accuracy of the Helicobacter pylori (H. pylori) stool antigen (HpSA) test and ImmunoCard STAT HpSA in the primary diagnosis of H. pylori infection.

METHODSWe searched Medline (1966-2007.4), EMbase (1985-2007.4), Chinese Journals Full-text Database (CJFD) (1994-2007) etc. to identify Clinical Trials of ImmunoCard STAT HpSA for the primary diagnosis of H. pylori infection. Meta-analysis was conducted using the method recommended by The Cochrane Collaboration Center.

RESULTSEleven trials were included with pooled sensitivity, pooled specificity as 0.93 (95% CI: 0.91-0.94), 0.93 (95% CI: 0.90- 0.95), respectively. Pooled positive likelihood ratio and pooled negative likelihood ratio were 12.01 (95% CI: 8.90-16.19), 0.08 (95% CI: 0.07-0.11), respectively with the pooled diagnostic odds ratio as 160.14(95% CI :100.43-255.34). The area under the summary receiver operating characteristic (SROC) was 0.974 +/- 0.005.

CONCLUSIONImmunoCard STAT HpSA appeared to be an accurate non-invasive method for the initial diagnosis of H. pylori infection.

Antigens, Bacterial ; immunology ; Feces ; microbiology ; Helicobacter Infections ; diagnosis ; immunology ; Helicobacter pylori ; immunology ; isolation & purification ; pathogenicity ; Reagent Kits, Diagnostic ; Sensitivity and Specificity

OBJECTIVETo establish an improved procedure for isolation and identification of epitopes from a random peptide library displayed on the bacterial surface.

METHODSEpitopes were screened from FliTrx random peptide library by a monoclonal antibody 3B9 against HBV-PreS2 protein. The enrichment was monitored in each round. Higher affinity clones were obtained by increasing the washing strength and randomly selected for sequencing and Western blot analysis.

RESULTSClones specifically binding to antibody were enriched in each round. Ten sequences were obtained from sixteen sequenced clones, seven of them contained the common motif RXRGXY with high homogeneity to 135-140 amio acids in HBV-PreS protein and have positive results in Western blot analysis. The other three sequences have no typical motif RXRGXY and showed different Western blot results.

CONCLUSIONSIt's easy and quick to drive epitopes from a random peptide library displayed on the bacterial surface.

Amino Acid Sequence ; Animals ; Antigens, Viral ; immunology ; Bacterial Proteins ; immunology ; Flagellin ; immunology ; Hepatitis B Surface Antigens ; genetics ; immunology ; isolation & purification ; Immunodominant Epitopes ; immunology ; Molecular Sequence Data ; Peptide Library ; Protein Precursors ; genetics ; immunology ; isolation & purification

Antigens, Bacterial ; immunology ; Antigens, Surface ; immunology ; China ; epidemiology ; Diarrhea ; microbiology ; Escherichia coli Infections ; epidemiology ; microbiology ; Escherichia coli O157 ; classification ; immunology ; isolation & purification ; Humans

Vibrios are universal conditioned-pathogenic bacteria in marine culture environment, and the outbreak of vibrio disease resulted in a serious damage to aquaculture. Considering that vibrio disease in aquatic species, especially fishes, usually originated from mixed infection of different species (serotypes or subspecies) of vibrios, it is important to select the potential cross-protective protein antigens as candidates of polyvalent or combined vaccines. In present research, several strains of vibrios were isolated from infected large yellow croaker (Pseudosciaena crocea) and subsequently identified as six strains of V. harveyi, one V. parahaemolyticus and one V. alginolyticus by physiological, biochemical and molecular biological methods. Their outer membrane proteins (OMPs) were extracted and the SDS-PAGE and Western blotting results show that three immuno-blots with common molecular weight presented at approximate 45 kDa, 35 kDa and 22 kDa on their OMP electrophoretogram, indicating the existence of antigens with cross-protection in their OMPs. With the aids of combination of two-dimensional electrophoresis (2-D) and Western blotting and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), a deduced porin (GenBank Accession No. ZP_01260407) from V. alginolyticus and a maltoporin precursor (GenBank Accession No. NP_801154) from V. parahaemolyticus were able to react with polyclonal antibody to whole V. harveyi, suggesting these two proteins could act as the cross-protective antigens and the vaccines prepared with these porins would be probable to bring cross protection to three different vibrios.
Animals ; Antigens, Bacterial ; immunology ; Bacterial Outer Membrane Proteins ; immunology ; Cross Reactions ; Fish Diseases ; microbiology ; Perciformes ; microbiology ; Vibrio ; classification ; immunology ; isolation & purification ; pathogenicity ; Vibrio Infections ; microbiology

Antibodies, Bacterial ; blood ; Antigens, Bacterial ; biosynthesis ; Bacterial Proteins ; biosynthesis ; Carrier Proteins ; biosynthesis ; Gastritis ; microbiology ; Helicobacter Infections ; immunology ; Helicobacter pylori ; immunology ; isolation & purification ; Humans ; Recombinant Proteins ; biosynthesis

Induced by 42 degrees C, the recombinant engineering bacterial pBV/cpa408 was highly expressed. After having been pelleted by 80% (NH4)2 SO4 and dialysised, the expressed protein was isolated and purified by the gel filtration choromatography. Then according to an amount of 1.0 mg/kg, the Kunming Mice (body weighted 18g) were immuned with the purified protein by intraperitoneal inoculation. One week after the first enhanced immunization, the Kunming Mice were attacked with an amount of 1.0MLD alpha-toxin, in which the eight mice immuned all survive and the control group all died. During the period of immunization, the titre of the mouse's serum antibody was measured by ELISA. One week after the first immunization, the titre of the mice's serum antibody was 1:800, but that of one week after the first enhanced immunization reached to 1:6400.
Animals ; Antibodies, Bacterial ; blood ; Antigens, Bacterial ; biosynthesis ; immunology ; Bacterial Toxins ; immunology ; Calcium-Binding Proteins ; immunology ; Female ; Immunization ; Male ; Mice ; Recombinant Proteins ; biosynthesis ; immunology ; isolation & purification ; Type C Phospholipases ; immunology

We utilized polyethylenimine (PEI) and Glu solution to immobilize the antibody of Treponema Pallidum on the silver electrode of piezoelectric quartz crystal and detect the standard antigen solution at different concentration. The antibody keeps the intrinsic Y type molecular structure revealed by AFM. The resonant range of the sensor is between 5 x 10(-5) - 1.25 x 10(-4) g/mL and the correlation coefficient is 0.9976, the optimal resonance pH is 7.5. We found the sensor having good selectivity in comparison with the method using BSA. At last, a discussion on the reproducibility of the sensor is presented.
Antibodies, Bacterial ; immunology ; Antigens, Bacterial ; analysis ; Biosensing Techniques ; instrumentation ; Equipment Design ; Immunoassay ; instrumentation ; methods ; Microelectrodes ; Polyethyleneimine ; Quartz ; Treponema pallidum ; immunology ; isolation & purification

This experiment was conducted to assess the efficacy of typhoid vaccine newly produced by purifying Vi antigen of Salmonella typhi. With Karber method, LD50 of challenging organism (S. typhi ty2) was determined as 6.31 CFU/mouse, and then the organism was used for the study. With Probits method, ED50 of the vaccine was determined as 0.016 microgram / 0.5 ml / mouse. The ELISA titer (0.5097+/-0.0606) was 4 times in the group treated with high dose (0.25 microgram/0.5ml) as in control (0.1113+/-0.0110). Six major protein bands of 66, 55, 35, 33, 18, and 9 kd were detected in Western blot analysis with serum of a vaccine treated mouse, whereas only one weak band of about 35 kd was detected with serum of a control mouse. We concluded that typhoid vaccine produced by purifying Vi antigen of S. typhi very effectively prevent S. typhi infection in mice.
Animals ; Antibodies, Bacterial/immunology ; Antigens, Bacterial/*immunology/*isolation&purification ; Blotting, Western ; Enzyme-Linked Immunosorbent Assay ; Lethal Dose 50 ; Logistic Models ; Male ; Mice ; Mice, Inbred BALB C ; Polysaccharides, Bacterial/*immunology/*isolation&purification ; Salmonella typhi/chemistry/*immunology ; Typhoid Fever/immunology/prevention&control ; Typhoid-Paratyphoid Vaccines/administration & dosage/*immunology/*isolation&purification

OBJECTIVETo establish a recombinant plasmid of CFP32 of Mycobacterium tuberculosis in E. coli, and to analyze its antigenicity.

METHODSRv0577 gene was amplified by polymerase chain reaction from genome of Mycobacterium tuberculosis, and then cloned into vector pMD18-T followed by the subclone into the expression vector pET21a. Recombinant CFP32 was expressed and purified. The antigenicity of the recombinant protein was analyzed by using Western-blot. The purified recombinant CFP32 protein was used as an antigen to screen the sera of 7 pulmonary TB patients (n = 97), as well as the other pulmonary disease patients (n = 25), and the clinically healthy controls (n = 38) by ELISA.

RESULTSRecombinant plasmid of CFP32 was established, and be expressed efficiently in E. coli BL21 (DE3). The relative molecular mass of the protein was about 300,000 by SDS-PAGE analysis. The protein purified by Ni-NTA was in a purity over 90%, which was confirmed by Western-blot analysis. ELISA analysis showed its sensitivity and specificity were 63.9% (62/97) and 96.8% (2/63) respectively.

CONCLUSIONThe recombinant expression plasmid pET21a CFP32 has been constructed and CFP32 proteins has been successfully expressed and be purified in E. coli and, ELISA analysis has identified the recombinant CFP32 as a candidate antigen for TB serodiagnosis.

Antigens, Bacterial ; blood ; Bacterial Proteins ; genetics ; immunology ; Cloning, Molecular ; Escherichia coli ; Gene Expression ; Humans ; Mycobacterium tuberculosis ; genetics ; isolation & purification ; Plasmids ; Recombinant Proteins ; Serologic Tests ; Tuberculosis, Pulmonary ; diagnosis ; microbiology

OBJECTIVETo clone tpn17 and tpn47 genes of Treponema pallidum and then construct their prokaryotic expression systems,to establish ELISAs based on rTpN17 and rTpN47 as antigens and to evaluate the sensitivity and specificity of the ELISAs for detection of serological diagnosis of syphilis.

METHODSThe whole length of tpn17 and tpn47 genes was amplified by PCR and then their prokaryotic expression systems were constructed. SDS-PAGE was used to measure the expression of the target recombinant proteins rTpN17 and rTpN47. Ni-NTA affinity chromatography was applied to extract rTpN17 and rTpN47, while Western blot was performed to determine the specific immunoreactivity of rTpN17 and rTpN47. By using rTpN17 and rTpN47 as the coated antigen, respectively, ELISAs (rTpN17-ELISA and rTpN47-ELISA) were established to detect serum samples from 200 healthy individuals, 25 RA patients, 17 SLE patients and 211 syphilis patients. The detection effects of the ELISAs were compared to those of TRUST and TPHA.

RESULTThe sequence similarity of the cloned tpn17 and tpn47 genes was 100 % compared with the corresponding sequences in GenBank. The expression outputs of rTpN17 and rTpN47 were approximately 37.2 % and 26.8 % of the total bacterial proteins, respectively. Both the extracted rTpN17 and rTpN47 could take place remarkable conjugation reactions to the sera with positive antibody against Treponema pallidum.The positive detection rate of TPHA (99.1%) was the highest (P<0.001). The positive detection rates of rTpN17-ELISA (85.3 %) and rTpN47-ELISA (84.3 %) were similar (P>0.05). The positive detection rates of TRUST (72.5 %) was lower than that of rTpN17-ELISA (P=0.001) but similar to that of rTpN47-ELISA (P=0.014). The detection results of all the serum samples from healthy individuals, RA patients and SLE patients were negative, whereas 7.1 % (3/42) of the samples from RA or SLE patients were positive.

CONCLUSIONrTpN17 and rTpN47 are still maintaining their original immunoreactivity. The ELISAs using rTpN17 or rTpN47 as the antigen are rapid, simple and convenient, higher sensitivity and specificity methods for serological screening and detection of syphilis.

Antibodies, Bacterial ; Antigens, Bacterial ; Blotting, Western ; Enzyme-Linked Immunosorbent Assay ; methods ; Female ; Humans ; Male ; Syphilis ; diagnosis ; Syphilis Serodiagnosis ; Treponema pallidum ; chemistry ; immunology ; isolation & purification