Animals ; Antibodies, Bacterial ; blood ; Cholera Toxin ; immunology ; Cholera Vaccines ; immunology ; Fimbriae, Bacterial ; immunology ; Mice ; Vibrio cholerae O139 ; immunology

ObjectiveGastroscopy combined with gastric mucosa biopsies is currently regarded as a gold standard for diagnosis of gastric cancer. However, its application is restricted in clinical practice due to its invasive property. A new noninvasive population screening process combining the assay of anti-Helicobacter pylori antibody and serum pepsinogen (PG) (ABC method) is adopted to recognize the high-risk patients for further endoscopy examination, avoiding the unnecessary gastroscopy for most population and saving the cost consumption for mass screening annually. Nevertheless, controversies exist for the grouping of ABC method and the intervals of gastroscopy surveillance for each group. In this review, we summarized these popular concerned topics for providing useful references to the healthcare practitioner in clinical practice.

Data SourcesThe PubMed databases were systematically searched from the inception dates to November 22, 2017, using the keywords "Helicobacter pylori," "Pepsinogens," and "Stomach Neoplasms."

Study SelectionOriginal articles and reviews on the topics were selected.

ResultsAnti-H. pylori antibody and serum PG concentration showed significant changes under the different status of H. pylori infection and the progression of atrophic gastritis, which can be used for risk stratification of gastric cancer in clinic. In addition, anti-H. pylori antibody titer can be used for further risk stratification of gastric cancer contributing to determine better endoscopy surveillance interval.

ConclusionsThe early detection and diagnosis of gastric cancer benefit from the risk stratification, but the cutoff values for H. pylori antibody and serum PG concentration require further modification.

Antibodies, Bacterial ; blood ; immunology ; Gastroscopy ; Helicobacter Infections ; blood ; immunology ; Helicobacter pylori ; immunology ; Humans ; Mass Screening ; methods ; Stomach Neoplasms ; blood ; microbiology

No abstract available.
Animal ; Antibodies, Bacterial/blood ; Antigens, Bacterial/blood ; Human ; Mites/microbiology ; Orientia tsutsugamushi/classification/immunology ; Scrub Typhus/diagnosis/*epidemiology/immunology

OBJECTIVETo detect leptospiral antibodies by microscopic agglutination test (MAT) in north-east of Iran.

METHODSThis study was conducted to evaluate prevalence of human leptospiral infections by MAT, using six current reference strains of Leptospira interrogans in north-east of Iran. A total of 285 serum samples were collected from three north-east provinces of Iran, from December, 2009 to June, 2010.

RESULTSAntibodies were detected at least against one serovar of Leptospira interrogans in 45 sera (15.79 %) among 285 samples at a dilution 1:100 or greater. Positive titers against more than one serovar were detected in 24 sera of the positive samples. Therefore, there were 75 positive reactions against different serovar of Leptospira interrogans. Positive titers were recorded against serovar icterohaemorrhagiae (31 samples), hardjo (26 samples), grippotyphosa (7 samples), pomona (5 samples), canicola (4 samples) and ballum (2 sample).

CONCLUSIONSIn present study the most prevalent (Leptospira icterohaemorrhagiae) and the least prevalent (Leptospira ballum) serovar are different from previous studies. Maybe, species and prevalence of serovars change during the time in one area and between regions.

Agglutination Tests ; Antibodies, Bacterial ; blood ; immunology ; Humans ; Iran ; epidemiology ; Leptospira ; classification ; immunology ; Leptospira interrogans ; immunology ; Leptospirosis ; epidemiology ; immunology ; Prevalence ; Serogroup

OBJECTIVEA systematic meta-analysis was performed to explore the role of cytotoxin-associated gene-A (CagA) seropositive strains of Helicobacter pylori (H. pylori) in the pathogenesis of atherosclerotic diseases. Data sources Data from Medline, EMBASE, CBMdisc, CNKI and the Cochrane Collaboration database were searched. Similar search strategies were applied to each of these databases. Study selection The review was restricted to the case-control studies on infective, chronic virulent CagA strains of H. pylori, involving the risk of ischemic stroke and coronary heart disease, ineligible studies were excluded. Two reviewers independently extracted the data and assessed study quality.

RESULTSTotally 26 case-control studies (11 studies on ischemic stroke and 15 studies on coronary heart disease) were retrieved and considered. The combined data revealed that the chronic seropositive virulent strains of H. pylori infection had a trend of increasing the risk of ischemic strokes and coronary heart diseases, yielding pooled ORs of 2.68 (95% CI: 2.20, 3.27) and 2.11 (95% CI: 1.70, 2.62), respectively. We also performed subgroup analyses, dividing the total population into Caucasian and Chinese subgroups. Through the subgroup analysis, no significant difference was found between the subgroups.

CONCLUSIONSOur results support the hypothesis that CagA-seropositive strains infection is significantly associated with susceptibility to ischemic strokes and coronary heart diseases. The magnitude of the association with atherosclerotic diseases needs to be confirmed by prospective studies and the studies on CagA-seropositive strains eradication are more important.

Antibodies, Bacterial ; blood ; Antigens, Bacterial ; immunology ; Atherosclerosis ; etiology ; pathology ; Bacterial Proteins ; immunology ; Helicobacter Infections ; blood ; complications ; microbiology ; Helicobacter pylori ; immunology ; pathogenicity ; Virulence

This study is designed to evaluate the immune status of schoolchildren with respect to Streptococcus pyogenes, and to ascertain the usefulness of antideoxyribonuclease B (ADNase B). Antistreptolysin O (ASO) and ADNase B concentrations were measured quantitatively in 266 serum samples from healthy elementary school children in Seoul. Simultaneously, throat cultures were taken in order to isolate S. pyogenes and other beta-hemolytic streptococci (BHS). The upper limits of the normal (ULN) concentration of ASO and ADNase B were 326 IU/mL, and 362 IU/mL, respectively. The correlation between ADNase B (y) and ASO (x) was y=0.4x+173 (r= 0.46). Mean ADNase B level (392 IU/mL) was significantly higher in children with S. pyogenes than in those with non-group A BHS (236 IU/mL) or no BHS (234 IU/ mL). Some schoolchildren were proven, via ASO and ADNase B tests, to be harboring asymptomatic S. pyogenes infections. The high ULN of ASO and ADNase B in schoolchildren should be carefully considered, in order to interpret the data collected from the patients. We could add the ADNase B test to our set of diagnostic tools, which would allow us to more accurately detect and diagnose streptococcal infections, as ADNase B was more specifically related to the results of throat cultures, and there was little correlation between ASO and ADNase B.
Antibodies, Bacterial/*blood ; Bacterial Proteins/immunology ; Child ; Deoxyribonucleases/*immunology ; Female ; Humans ; Korea ; Male ; Serologic Tests ; Streptococcal Infections/*diagnosis/*immunology ; Streptococcus pyogenes/enzymology/*immunology ; Streptolysins/immunology

OBJECTIVEIn order to evaluate the safety and immunogenicity of group A + C meningococcal polysaccharide vaccine, a controlled field trial was performed among children at 6-24 months and 5-13 years old in Longsheng county, Guangxi Zhuang Autonomous Region.

METHODSMore than 600 children were selected in this trial. 428 children, aged 6-24 month-old and 5-13 year-old were involved in two experimental groups and were inoculated 100 microg of group A + C meningococcal polysaccharide vaccine. 103 children in positive control group were inoculated 50 microg of group A meningococcal polysaccharide vaccine while 94 children in negative control group were inoculated 30 microg of Typhoid Vi polysaccharide vaccine. Both systemic and local reactions were observed in each group at 6 h,24 h,48 h and 72 h after inoculation. Blood samples were collected in all children before and at 1 month after inoculation. Additionally, at least 50 blood samples were taken in each experimental group at 6 and 12 months after inoculation. Serum bactericidal antibody was tested by micro bactericidal test.

RESULTSBoth systemic and local reactions were mild in two experimental groups with only 3 children (0.7%) had > or = 37. 6 degrees C fever, 4 children (0.9%) appeared mild areola but all adverse reaction disappeared within 48 hours. In 5-13 year-old experimental group, the rates for four-fold increase of bactericidal antibody were 96.59% and 92.15% to group A and group C meningococcus respectively at 1 month after inoculation, and remained 90.91% and 90.08% at 12 months after inoculation.

CONCLUSIONGroup A + C meningococal polysaccharide vaccine was safe and having good immunogenicity among Chinese children.

Adolescent ; Antibodies, Bacterial ; blood ; immunology ; Child ; Child, Preschool ; Female ; Humans ; Infant ; Male ; Meningococcal Vaccines ; adverse effects ; immunology ; Polysaccharides, Bacterial ; adverse effects ; immunology ; Typhoid-Paratyphoid Vaccines ; adverse effects ; immunology

Staphylococcus aureus is a major cause of hospital-acquired infection. Because the bacteria are very easy to become resistant to antibiotics, vaccination is a main method against S. aureus infection. Clumping factor B (ClfB) is an adhesion molecule essential for S. aureus to colonize in the host mucosa and is regarded as an important target antigen. In this study, we successfully used Escherichia coli to express a segment encoding the N1-N3 regions of ClfB protein (Truncated-ClfB) cloned from S. aureus. The protein was purified by affinity and ion exchange chromatographies and gel filtration. Rabbits were immunized three times with purified Truncated-ClfB. After that, blood was collected to prepare serum which were then used for measurement of antibody level. Phagocytosis of S. aureus opsonized by the serum was determined by a flow cytometry. Results show that the serum IgG titer reached 1:640 000. Phagocytosed S. aureus by polymorphonuclear leukocytes were significantly more when the bacteria were opsonized by the serum from Truncated-ClfB immunized rabbits than those from no immunized group (P < 0.01). Therefore, the results indicated that Truncated-ClfB could be a promising vaccine candidate against S. aureus infection.
Adhesins, Bacterial ; immunology ; Animals ; Antibodies, Bacterial ; blood ; Escherichia coli ; Flow Cytometry ; Immune Sera ; Immunoglobulin G ; blood ; Opsonin Proteins ; immunology ; Phagocytosis ; Rabbits ; Staphylococcal Infections ; immunology ; Staphylococcus aureus

To analyze the immunogenicity and protective ability of recombinant IgG-binding protein (EAG) of Streptococcus equi subspecies equi and to evaluate its value when used as equine vaccine antigen, EAG gene was amplified by PCR and inserted into pET-28a vector. The EAG recombinant proteins were expressed and purified to immune mice. The serum antibody and challenge protection were tested. The purified recombinant protein of EAG was 26 kDa, and the protein reacted specifically with positive serum of Streptococcus equi subspecies equi. The mice antibody level for EAG immunization group was 1∶8 100. The immunological protection result showed that the protection rate of the EAG recombinant protein was 90%. The results suggested that the EAG protein has good immunogenicity and immunological protection, and it can effectively increase the humoral immune response and immunological protection of mice.
Animals ; Antibodies, Bacterial ; blood ; Antigens, Bacterial ; immunology ; Bacterial Proteins ; immunology ; Bacterial Vaccines ; immunology ; Immunity, Humoral ; Immunoglobulin G ; blood ; Mice ; Polymerase Chain Reaction ; Protein Binding ; Recombinant Proteins ; immunology ; Streptococcal Infections ; prevention & control ; Streptococcus equi ; Vaccination

OBJECTIVETo determine the distribution and sequence conservation of pagC gene in Salmonella paratyphi A isolates, and the immunogenicity and immunoprotection of its recombinant expression products (rPagC).

METHODSThe distribution of pagC gene in Salmonella paratyphi A isolates and its sequence conservation were examined by PCR and sequencing. A prokaryotic expression system of pagC gene was constructed and the expressed rPagC was extracted by Ni-NTA affinity chromatography. SDS-PAGE and Bio-Rad Gel Image Analyzer were applied to examine the expression and yield of rPagC. The antigenicity and immunoreactivity of rPagC were detected by immunodiffusion test, ELISA and Western Blot assay. The immunoprotective effect of rPagC against infection of Salmonella paratyphi A in mice was determined, while the agglutinative effect of sera from rPagC-immunized mice was measured by micro-Widal's test.

RESULTSAll the Salmonella paratyphi A isolates tested had the pagC gene, the similarity of nucleotide and amino acid sequences was 99.1 %-100 % and 98.4 %-100 %, respectively. The constructed prokaryotic expression system expressed rPagC with high efficiency. The rPagC immunized rabbit produced a high level antibody and it also combined with antiserum against whole cell of S. paratyphi A to generate a positive Western hybridization signal. ELISA results indicated that 97.1 % (66/68) paratyphoid patients infected with Salmonella paratyphi A were positive for rPagC antibody in their serum specimens. When mice were immunized with 100 μg or 200 μg rPagC, the immunoprotective rates were 73.3 % (11/15) or 86.7 % (13/15), respectively. The sera from rPagC-immunized mice offered 1:10-1:40 agglutination titers with the H antigens of Salmonella paratyphi A and Salmonella typhi.

CONCLUSIONPagC gene has an extensive distribution in Salmonella paratyphi A isolates. rPagC can be used as the candidate antigen in genetic engineering vaccine due to its fine immunogenicity and powerful immunoprotective effect.

Agglutination Tests ; Animals ; Antibodies, Bacterial ; blood ; Antigens, Bacterial ; genetics ; immunology ; Bacterial Proteins ; genetics ; immunology ; Bacterial Vaccines ; Membrane Proteins ; genetics ; immunology ; Mice ; Rabbits ; Recombinant Proteins ; genetics ; immunology ; Salmonella paratyphi A ; genetics ; immunology ; Sequence Homology, Amino Acid ; Sequence Homology, Nucleic Acid