Cystic echinococcosis (CE) in sheep is a hazardous zoonotic parasitic disease that is caused by Echinococcus granulosus (Eg). At present, serological test is an important diagnostic method for Eg infection in domestic animals. Here, a fusion protein Eg mefAg-1 harboring 8 dominant B-cell epitopes of Eg such as antigen B, tetraspanin 1, tetraspanin 6, reticulon and Eg95 was produced in E. coli and evaluated for CE in sheep by indirect ELISA. Eg mefAg-1 showed in ELISA a high sensitivity (93.41%) and specificity (99.31%), with a coincidence rate of 97.02%. Overall, it is suggested that the Eg mefAg-1 could be a potential antigen candidate for CE serodiagnosis in sheep.
Animals, Domestic ; Echinococcosis ; Echinococcus granulosus ; Enzyme-Linked Immunosorbent Assay ; Epitopes, B-Lymphocyte ; Methods ; Parasitic Diseases ; Sensitivity and Specificity ; Serologic Tests ; Sheep

BACKGROUND: Serologic testing is considered a standard method for syphilis diagnosis. We compared Auto RPR Plus and Auto TPIM Plus with previously developed assays. METHODS: The precision around the cut-off, linearity, and recovery rate of Auto RPR Plus and Auto TPIM Plus was evaluated using their positive/negative control materials. The results of these two tests were compared with those of Mediace RPR and Abbott Syphilis TP using 431 remnant serum samples collected from people who underwent medical examinations. RESULTS: The within-run precisions (coefficient of variation, CV values) of negative/positive control materials of Auto RPR Plus, Mediace RPR, Auto TPIM Plus and Abbott Syphilis TP were 15.7/2.3%, 20.4/2.3%, -/2.7%, and 8.5/2.3%, respectively; between-run precisions were 67.7/3.3%, 39.1/3.4%, -/4.0%, and 7.0/1.5%, respectively. Auto RPR Plus showed better precision around the cutoff level (1.0 U) compared to Mediace RPR (7.2–7.3% vs. 12.2–14.3%). The CVs of Auto TPIM Plus around the cutoff (10.0 U) were 13.5% at 10.5 U and 6.6% at 12.5 U. Agreement rates between Auto RPR Plus and Mediace RPR and between Auto TPIM Plus and Abbott Syphilis TP were 97.2% and 98.4%, respectively. However, twelve samples showed discrepant results for Auto RPR Plus (−)/Mediace RPR (+) and false-positive Mediace RPR results could not be excluded around the cutoff of 1.0 U. CONCLUSIONS: Auto RPR Plus showing good precision near the cutoff can be used for syphilis screening in health checkups. However, Auto TPIM Plus needs improvement in precision and adjusting the cutoff to be used for syphilis screening.
Diagnosis* ; Mass Screening ; Methods ; Serologic Tests ; Syphilis*

BACKGROUND: To improve Rh-related antigen negative blood supply effectively, the Korean Red Cross (KRC) blood centers have performed Rh phenotype screening tests of C, c, E and e antigens for all donors since April, 2013. Especially for rare ‘-D-/-D-’ blood supply and donor recruitment, we have implemented Rh phenotype confirmation test for all C, c, E and e antigen negative donors. In this study, we report the test results of 7 donors with ‘-D-/-D-’ phenotype. METHODS: All three KRC Blood Laboratory Centers performed Rh phenotype screening tests using the automatic machine, PK7300 (Beckman Coulter, Japan), for all 876,920 donors from January 1, 2018 to April 30, 2018. We then performed the Rh phenotype confirmation test using the tube method manually, at room temperature, 37℃ and antihuman globulin phase. RESULTS: Among 876,920 donors, 14 were Rh antigen C, c, E, e negative as results of Rh phenotype screening test. The results of Rh phenotype confirmation test of these 14 donors showed that 7 donors were Rh antigen C, c, E, e negative. The ratio of -D-/-D- phenotype for all donors was 0.000798%. CONCLUSION: Our data suggests that -D-/-D- phenotype is one of the rare blood groups among Koreans. Although ‘-D-/-D-’ phenotype was confirmed by serologic tests, it is necessary to re-confirm it by molecular genetic techniques.
Blood Group Antigens ; Hepatitis B e Antigens ; Humans ; Mass Screening ; Methods ; Molecular Biology ; Phenotype* ; Red Cross ; Serologic Tests ; Tissue Donors*

Soluble antigens from an axenic culture of Entamoeba histolytica were used to develop a commercial ELISA kit to quantify anti-E. histolytica antibodies in sera of patients with extraintestinal amebiasis in non-endemic settings. The diagnostic specificity and sensitivity of the test were assessed retrospectively using 131 human serum samples with amoebic serologic status available. They were selected according to their results in immunofluorescence (IFAT) and were separated in 2 sample categories: 64 sera with positive results by IFAT and 67 with negative results by IFAT. The sensitivity and specificity of the ELISA kit were assessed at 95.0% and 94.0% compared to the IFAT. The test can be useful to exclude a potential diagnosis of amebiasis and could be used as a screening method since ELISA is an automated technique.
Amebiasis ; Antibodies ; Axenic Culture ; Diagnosis ; Entamoeba histolytica ; Enzyme-Linked Immunosorbent Assay ; Fluorescent Antibody Technique ; Humans ; Mass Screening ; Methods ; Retrospective Studies ; Sensitivity and Specificity ; Serologic Tests

Objective: This study aimed to understand the herpes simplex virus-2 (HSV-2) infection and related factors among female drug abusers in the women's compulsory drug rehabilitation center of Shandong province and to provide reference for the prevention and control of HSV-2 in these settings. Methods: We screened all of 451 female drug abusers in the women's compulsory drug rehabilitation centers in of Shandong province and conducted a study using both questionnaire investigation and serological tests for HSV-2, HIV and syphilis. We also used EpiData 3.1 software to establish a database and SPSS 20.0 software to conduct the χ(2) test and multivariate logistic regression analysis. Results: A total of 451 female drug abusers were under study. We noticed that the rates for HSV-2 infection, HIV infection and syphilis infection appeared as 72.1% (325/451), 2.2% (10/451) and 33.5% (151/451) respectively. Results from univariate analysis showed that factors as: awareness on AIDS, having temporary sex partner after using the drug, having multiple sex partners after using the drug, providing commercial services or having temporary sex practice before being detained, with syphilis infection etc., were associated with HSV-2 infection. Data from the multivariate analysis showed that the OR (95%CI) value of HSV-2 infection was 2.90 (1.19-7.06) for those who providing commercial service, when comparing to those who did not. Compared to those who did not suffer from syphilis infection, the OR (95%CI) value of HSV-2 infection for those with syphilis infection was 2.75 (1.63-4.63). Conclusions: The rate of HSV-2 infection was high in the women's compulsory drug rehabilitation center of Shandong province. We should enhance measures and promote condom use to prevent from HSV-2 and other sexually transmitted diseases among them.
Drug Users ; Female ; HIV Infections/epidemiology* ; Herpes Genitalis/epidemiology* ; Herpes Simplex/epidemiology* ; Herpesvirus 2, Human/isolation & purification* ; Humans ; Opiate Substitution Treatment ; Prevalence ; Risk Factors ; Serologic Tests/methods* ; Sexual Behavior ; Sexual Partners ; Substance Abuse Treatment Centers ; Substance-Related Disorders/rehabilitation* ; Syphilis/epidemiology*

Objective: To evaluate the serological diagnostic value of Mycobacterium (M.) tuberculosis four new antigens Rv0432, Rv0674, Rv1566c and Rv1547. Methods:Rv0432, Rv0674, Rv1566c and Rv1547 were amplified from M. tuberculosis strain H37Rv genomic DNA by using PCR, among which Rv1547 was divided into two segments for amplification (Rv1547-1 and Rv1547-2). The segments were cloned into expression vector PET-32a while the recombinant proteins were purified by affinity chromatography. Serums were incubated with BL21 (DE3) proteins. Antibodies IgG against M. tuberculosis were tested with 151 serum samples (41 healthy people and 110 TB patients) by using ELISA. The diagnostic efficiency of antigens was analyzed by means of receiver operating characteristic curve. Difference of the objective proteins in TB patients and healthy controls was compared by t-test. Results: Recombinant antigens Rv0432, Rv0674, Rv1566c, Rv1547-1 and Rv1547-2 were successfully expressed and purified. Results from ELISA showed that the sensitivity, specificity, positive predictive value, negative predictive value, Youden index and area under the curve of Rv0432, Rv0674, Rv1566c, Rv1547-1 and Rv1547-2, as 43.64%-92.73%, 80.49%-92.68%, 0.92-0.94, 0.38-0.80, 0.363-0.732 and 0.649-0.915. All the objective proteins showed significantly higher antibody levels in TB patients, when compared to the healthy controls (P<0.000 1). Conclusion: The newly identified antigens Rv0432, Rv0674, Rv1566c, Rv1547-1 and Rv1547-2 all performed well when being used for TB serological diagnosis, thus were expected to be new candidate antigens used for TB diagnosis.
Antigens, Bacterial/genetics* ; Cloning, Molecular ; Enzyme-Linked Immunosorbent Assay ; Humans ; Immunoglobulin G ; Mycobacterium tuberculosis/metabolism* ; Polymerase Chain Reaction ; ROC Curve ; Recombinant Proteins ; Sensitivity and Specificity ; Serologic Tests/methods* ; Tuberculosis/genetics*

Swine vesicular disease (SVD) is a highly contagious viral disease that causes vesicular disease in pigs. The importance of the disease is due to its indistinguishable clinical signs from those of foot-and-mouth disease, which prevents international trade of swine and related products. SVD-specific antibody detection via an enzyme-linked immunosorbent assay (ELISA) is the most versatile and commonly used method for SVD surveillance and export certification. Inactivated SVD virus is the commonly used antigen in SVD-related ELISA. A recombinant SVD virus-like particle (VLP) was generated by using a Bac-to-Bac baculovirus expression system. Results of SVD-VLP analyses from electron microscopy, western blotting, immunofluorescent assay, and mass spectrometry showed that the recombinant SVD-VLP morphologically resemble authentic SVD viruses. The SVD-VLP was evaluated as a replacement for inactivated whole SVD virus in competitive and isotype-specific ELISAs for the detection of antibodies against SVD virus. The recombinant SVD-VLP assay produced results similar to those from inactivated whole virus antigen ELISA. The VLP-based ELISA results were comparable to those from the virus neutralization test for antibody detection in pigs experimentally inoculated with SVD virus. Use of the recombinant SVD-VLP is a safe and valuable alternative to using SVD virus antigen in diagnostic assays.
Animals ; Antibodies ; Baculoviridae ; Blotting, Western ; Certification ; Enterovirus B, Human ; Enzyme-Linked Immunosorbent Assay ; Foot-and-Mouth Disease ; Mass Spectrometry ; Methods ; Microscopy, Electron ; Neutralization Tests ; Serologic Tests* ; Swine Vesicular Disease* ; Swine* ; Virus Diseases

Angiostrongyliasis is difficult to be diagnosed for the reason that no ideal method can be used. Serologic tests require specific equipment and are not always available in poverty-stricken zone and are time-consuming. A lateral flow immunoassay (LFIA) may be useful for angiostrongyliasis control. We established a LFIA for the diagnosis of angiostrongyliasis based on 2 monoclonal antibodies (mAbs) against antigens of Angiostrongylus cantonensis adults. The sensitivity and specificity were 91.1% and 100% in LFIA, while those of commercial ELISA kit was 97.8% and 86.3%, respectively. Youden index was 0.91 in LFIA and 0.84 in commercial ELISA kit. LFIA showed detection limit of 1 ng/ml of A. cantonensis ES antigens. This LFIA was simple, rapid, highly sensitive and specific, which opened an alternative approach for the diagnosis of human angiostrongyliasis.
Adult ; Angiostrongylus cantonensis* ; Angiostrongylus* ; Antibodies, Monoclonal ; Diagnosis ; Enzyme-Linked Immunosorbent Assay ; Humans* ; Immunoassay* ; Limit of Detection ; Methods ; Sensitivity and Specificity ; Serologic Tests

INTRODUCTIONHerpes simplex virus type 2 (HSV-2) is the most common cause of genital herpes. Glycoprotein G (gG) is a prototype antigen for type-specific serodiagnosis distinguishing between HSV type 1 (HSV-1) and HSV-2 infections. As immunological diagnosis kits for accurate differentiation between HSV-1 and HSV-2 antibodies can be expensive, there is a need to develop a convenient, sensitive, specific and cost-effective serodiagnostic kit.

METHODSWe successfully expressed a fragment of gG comprising residues 321-580 of HSV-2 with histidine tag (gG(321-580His)) in a Bac-to-Bac baculovirus expression system, which had an antigenicity similar to its native counterpart. An indirect enzyme-linked immunosorbent assay (ELISA) was developed using gG(321-580His) as the diagnostic antigen and evaluated by comparison with a commercial HerpeSelect 2 ELISA immunoglobulin G kit as reference.

RESULTSIn testing 318 field serum samples, the diagnostic relative sensitivity and specificity of the developed gG(321-580His)-ELISA test in qualitative comparison with the commercial kit were 93.81% and 96.74%, respectively, and the accuracy was 94.65%.

CONCLUSIONThe study indicates that gG(321-580His) has a high diagnostic potential for HSV-2 virus serodiagnosis in humans.

Adult ; Antibodies, Viral ; blood ; Enzyme-Linked Immunosorbent Assay ; Female ; Herpes Genitalis ; diagnosis ; virology ; Herpes Simplex ; diagnosis ; virology ; Herpesvirus 1, Human ; isolation & purification ; Herpesvirus 2, Human ; isolation & purification ; Humans ; Immunoglobulin G ; chemistry ; Male ; Polymerase Chain Reaction ; Reagent Kits, Diagnostic ; Reference Values ; Reproducibility of Results ; Sensitivity and Specificity ; Serologic Tests ; methods

The mature domain of a cysteine protease of Spirometra erinacei plerocercoid larva (i.e., sparganum) was expressed in Escherichia coli, and its value as an antigen for the serodiagnosis of sparganosis was investigated. The recombinant protein (rSepCp-1) has the molecular weight of 23.4 kDa, and strongly reacted with the sparganum positive human or mice sera but not with negative sera by immunoblotting. ELISA with rSepCp-1 protein or sparganum crude antigen (SeC) was evaluated for the serodiagnosis of sparganosis using patient's sera. The sensitivity and specificity of ELISA using rSepCp-1 protein were 95.0% (19/20) and 99.1% (111/112), respectively. In contrast, the sensitivity and specificity of ELISA with SeC were 100% (20/20) and 96.4% (108/112), respectively. Moreover, in experimentally infected mice, the sensitivity and specificity of both ELISA assays were 100% for the detection of anti-sparganum IgG. It is suggested that the rSepCp-1 protein-based ELISA could provide a highly sensitive and specific assay for the diagnosis of sparganosis.
Animals ; Antigens, Helminth/chemistry/*diagnostic use/genetics ; Cloning, Molecular ; Cysteine Proteases/chemistry/*diagnostic use/genetics ; Enzyme-Linked Immunosorbent Assay ; Escherichia coli/genetics ; Gene Expression ; Humans ; Mice ; Molecular Weight ; Parasitology/*methods ; Recombinant Proteins/chemistry/diagnostic use/genetics ; Sensitivity and Specificity ; Serologic Tests/methods ; Sparganosis/*diagnosis ; Spirometra/*enzymology/genetics