OBJECTIVETo identify potential serum biomarkers for distinguishing between latent tuberculosis infection (LTBI) and active tuberculosis (TB).

METHODSA proteome microarray containing 4,262 antigens was used for screening serum biomarkers of 40 serum samples from patients with LTBI and active TB at the systems level. The interaction network and functional classification of differentially expressed antigens were analyzed using STRING 10.0 and the TB database, respectively. Enzyme-linked immunosorbent assays (ELISA) were used to validate candidate antigens further using 279 samples. The diagnostic performances of candidate antigens were evaluated by receiver operating characteristic curve (ROC) analysis. Both antigen combination and logistic regression analysis were used to improve diagnostic ability.

RESULTSMicroarray results showed that levels of 152 Mycobacterium tuberculosis (Mtb)-antigen- specific IgG were significantly higher in active TB patients than in LTBI patients (P < 0.05), and these differentially expressed antigens showed stronger associations with each other and were involved in various biological processes. Eleven candidate antigens were further validated using ELISA and showed consistent results in microarray analysis. ROC analysis showed that antigens Rv2031c, Rv1408, and Rv2421c had higher areas under the curve (AUCs) of 0.8520, 0.8152, and 0.7970, respectively. In addition, both antigen combination and logistic regression analysis improved the diagnostic ability.

CONCLUSIONSeveral antigens have the potential to serve as serum biomarkers for discrimination between LTBI and active TB.

Adolescent ; Adult ; Aged ; Antibodies, Bacterial ; Antibody Specificity ; Antigens, Bacterial ; Biomarkers ; blood ; Female ; Humans ; Latent Tuberculosis ; blood ; diagnosis ; Logistic Models ; Male ; Middle Aged ; Mycobacterium tuberculosis ; Protein Array Analysis ; methods ; Proteome ; genetics ; Proteomics ; methods ; ROC Curve ; Young Adult

Seasonal outbreaks of airsacculitis in China's poultry cause great economic losses annually. This study tried to unveil the potential role of Avian metapneumovirus (AMPV), Ornithobacterium rhinotracheale (ORT) and Chlamydia psittaci (CPS) in avian airsacculitis. A serological investigation of 673 breeder chickens and a case-controlled study of 430 birds were undertaken. Results showed that infection with AMPV, ORT, and CPS was highly associated with the disease. The correlation between AMPV and CPS were positively robust in both layers and broilers. Finally, we determined the co-infection with AMPV, ORT, and CPS was prevalent in the sampled poultry farms suffering from respiratory diseases and the outbreak of airsacculitis was closely related to simultaneous exposure to all three agents.
Air Sacs ; microbiology ; pathology ; Animals ; Antibodies, Bacterial ; blood ; Antibodies, Viral ; blood ; Case-Control Studies ; Chickens ; Chlamydia ; Chlamydia Infections ; microbiology ; pathology ; veterinary ; Coinfection ; Flavobacteriaceae Infections ; microbiology ; pathology ; veterinary ; Humans ; Metapneumovirus ; Ornithobacterium ; Paramyxoviridae Infections ; pathology ; veterinary ; virology ; Poultry Diseases ; microbiology ; pathology ; virology ; Respiratory Tract Diseases ; microbiology ; veterinary ; virology ; Seroepidemiologic Studies

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

Acinetobacter baumannii (A. Baumannii) is an emerging opportunistic pathogen responsible for hospital-acquired infections, and which now constitutes a sufficiently serious threat to public health to necessitate the development of an effective vaccine. In this study, a recombinant fused protein named OmpK/Omp22 and two individual proteins OmpK and Omp22 were obtained using recombinant expression and Ni-affinity purification. Groups of BALB/c mice were immunized with these proteins and challenged with a clinically isolated strain of A. baumannii. The bacterial load in the blood, pathological changes in the lung tissue and survival rates after challenge were evaluated. Mice immunized with OmpK/Omp22 fused protein provided significantly greater protection against A. baumannii challenge than those immunized with either of the two proteins individually. The results provide novel clues for future design of vaccines against A. baumannii.
Acinetobacter Infections ; pathology ; prevention & control ; Acinetobacter baumannii ; genetics ; immunology ; Animals ; Antibodies, Bacterial ; blood ; Bacterial Load ; Bacterial Outer Membrane Proteins ; genetics ; immunology ; Bacterial Vaccines ; immunology ; Disease Models, Animal ; Female ; Mice, Inbred BALB C ; Pneumonia, Bacterial ; pathology ; prevention & control ; Recombinant Fusion Proteins ; genetics ; immunology

OBJECTIVETo evaluation the specificity and sensitivity of 5 kinds of serological detection methods about brucellosis.

METHODSTo investigate in the 4 autonomous banner (Cha You Hou Qi, Right-Wing Central Banner of Kerqin Region, Linxi County and Siziwangqi Banner) of Inner Mongolia autonomous region from January to December, 2013. Accepting criteria: professionals of breeding cattle and sheep, and slaughter,accompanied by Bloom's disease suspected symptoms such as fever, fatigue,arthralgia, ranging in age from 25 to 55 years old. To collect suspected patients venous blood 3-5 ml in the morning, a total of 236 samples were collected. To detect the Brucella antibody by using plate agglutination test (PAT), tiger red plate agglutination test (RBPT), standard test tube agglutination test (SAT), enzyme-linked immunosorbent assay (ELISA) and immune colloidal gold method (GICA), SAT was taken as a golden standard, analyzed the sensitivity and specificity of RBPT and SAT, ELISA and GICA.

RESULTSSAT method of positive patients: 136 cases (57.6%). PAT method positive patients: 150 cases (63.6%). RBPT positive patients: 159 cases (67.4%), and 143 patients with ELISA method: positive (60.6%), 147 patients with positive GICA method (62.3%). The detection rate of Brucella antibody positive was different by different testing methods.There was no significant difference (χ(2)=0.52,P=0.264). To take the SAT method as the gold standard, PAT, RBPT, ELISA and GICA method of the sensitivity were 97.7% (133/136), 98.5% (134/136), 94.8% (129/136) and 94.1% (128/136), respectively. The specificity was lower,the rate were 70.0% (70/100), 75.0% (75/100), 86.0% (86/100) and 81.0% (81/100), respectively. The total coincidence rate were 86.0% (203/236), 88.5% (209/236), 91.1% (215/236) and 88.5% (209/236), respectively.

CONCLUSIONThe specificity and sensitivity of ELISA and GICA method is higher in the diagnosis of disease. The two methods are rapid, GICA method can be used on-site testing, large sample test is suitable for using ELISA.

Adult ; Agglutination Tests ; methods ; Animals ; Antibodies, Bacterial ; blood ; Brucella ; Brucellosis ; diagnosis ; Cattle ; China ; Enzyme-Linked Immunosorbent Assay ; Humans ; Middle Aged ; Sensitivity and Specificity ; Sheep

Recombinant Fl-V (rFl-V) fusion protein is the main ingredient of the current candidate vaccine against Yersinia pestis infection, which has been under investigation in clinical trial in USA. We investigated the soluble expression conditions of rF1-V in Escherichia coli BL21 (DE3) that we constructed before. After scale-up and optimization of fermentation processes, we got the optimized fermentation process parameters: the culture was induced at the middle exponential phase with 50 µmol/L of IPTG at 25 °C for 5 h. Soluble rFl-V protein was isolated to 99% purity by ammonium sulfate precipitation, ion exchange chromatography, hydrophobic chromatography and gel filter chromatography. The protein recovery was above 20%. Protein identity and primary structure were verified by mass spectrometry and Edman sequencing. Results of purity, quality and western blotting analysis indicated that the target protein is a consistent and properly folded product. Furthermore, the immunogenicity of various antigens formulated with aluminum hydroxide adjuvant was evaluated in mice. Serum antibody titers of 4 groups including 20 µg rFl, rV and rFl-V and 10 µg rFl+10 µg rV, were assayed by ELISA after 2 doses. The antibody titers of anti-Fl with 20 µg rFl-V were obviously higher than titers with other groups; meanwhile there were no significant difference of anti-V antibody titers among them. These findings confirm that rFl-V would be the active pharmaceutical ingredient of the plague subunit vaccine.
Adjuvants, Immunologic ; Animals ; Antibodies, Bacterial ; blood ; Antibody Formation ; Antigens, Bacterial ; immunology ; Blotting, Western ; Chromatography, Ion Exchange ; Enzyme-Linked Immunosorbent Assay ; Mice ; Plague ; prevention & control ; Plague Vaccine ; immunology ; Recombinant Fusion Proteins ; immunology ; Vaccines, Subunit ; immunology ; Yersinia pestis

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 study the role of Mycoplasma pneumoniae (MP) load and antibody measurements in the diagnosis of MP pneumonia.

METHODSA total of 115 children with MP pneumonia and 400 healthy children were enrolled. The MP load and total antibody level were measured at different stages, and the MP load index (MPLI) was calculated.

RESULTSThe cut-off value of MPLI for MP infection was 6.12. MPLI and total antibody titer increased during the course of the disease, while MP-DNA decreased rapidly. Within the same time of blood collection, the group with a higher MP load had a significantly higher total antibody titer than the group with a lower MP load (P<0.05). Within 2 weeks of the course of the disease, the negative antibody group had a significantly higher MPLI than the positive antibody group (P<0.05).

CONCLUSIONSMPLI provides a standardized quantitative value of MP-DNA and plays an important role in the early diagnosis of MP infection.

Antibodies, Bacterial ; blood ; Child ; Child, Preschool ; DNA, Bacterial ; analysis ; Early Diagnosis ; Female ; Humans ; Infant ; Male ; Pneumonia, Mycoplasma ; diagnosis ; microbiology

Although it is well known that pneumococcal conjugate vaccines provide cross-protection against some vaccine-related serotypes, these mechanisms are still unclear. This study was performed to investigate the role of cross-protective IgM antibodies against vaccine-related serotypes 6A, 6C, and 19A induced in children aged 12-23 months after immunization with 7-valent pneumococcal conjugate vaccine (PCV7). We obtained serum samples from 18 Korean children aged 12-23 months after a PCV7 booster immunization. The serum IgG and IgM concentrations of serotypes 6B and 19F were measured by enzyme-linked immunosorbent assay (ELISA) in serum. The opsonic indices (OIs) against vaccine serotypes 6B and 19F and vaccine-related serotypes 6A, 6C, and 19A were determined by an opsonophagocytic killing assay (OPA) in IgM-depleted and control serum. Both IgG and IgM antibodies in ELISA and opsonic indices in OPA against serotypes 6B and 19F were demonstrated in the immune serum. IgM depletion decreased the OIs against vaccine serotypes 6B (geometric means of OIs (GMIs) of 3,009 vs. 1,396, 38% reduction) and 19F (1,117 vs. 750, 36% reduction). In addition, IgM depletion markedly decreased the OIs against vaccine-related serotypes 6A (GMIs of 961 vs. 329, 70% reduction), 6C (432 vs. 185, 72% reduction), and 19A (301 vs. 166, 58% reduction). The booster immunization PCV7 induced protective antibodies in the form of both IgG and IgM isotypes. IgM antibodies contributed to eliciting cross-protection against vaccine-related serotypes as well as against vaccine serotypes.
Antibodies, Bacterial/blood ; Antibodies, Neutralizing/blood ; Enzyme-Linked Immunosorbent Assay ; Heptavalent Pneumococcal Conjugate Vaccine/*immunology ; Humans ; Immunoglobulin M/*blood ; Infant ; Pneumococcal Infections/*prevention & control ; Pneumococcal Vaccines/*immunology ; Serogroup ; Streptococcus pneumoniae/immunology

Lyme disease is a tick-borne zoonotic infectious disease caused by Borrelia burgdorferi. The present study assessed the infection status of B. burgdorferi among horses reared in Korea using ELISA and PCR. Between 2009 and 2013, blood samples were collected from 727 horses throughout Korea. Data for each animal including age, gender, breed, and region of sample collection were used for epidemiological analysis. Overall, 38 (5.2%; true prevalence: 5.5%) of 727 horses were seropositive by ELISA. There were statistically significant differences according to breed and region (P<0.001) whose differences might be attributed to the ecology of vector ticks and climate conditions. Using 2 nested PCR, none of the samples tested positive for B. burgdorferi. Thus, a positive ELISA result can indicate only that the tested horse was previously exposed to B. burgdorferi, with no certainty over the time of exposure. Since global warming is likely to increase the abundance of ticks in Korea, continuous monitoring of tick-borne diseases in Korean horses is needed.
Animals ; Antibodies, Bacterial/blood ; Borrelia burgdorferi/*physiology ; Enzyme-Linked Immunosorbent Assay/veterinary ; Female ; Horse Diseases/*epidemiology ; Horses ; Lyme Disease/epidemiology/*veterinary ; Male ; Republic of Korea/epidemiology