scholarly journals Characterization and evaluation of a recombinant multiepitope peptide antigen MAG in the serological diagnosis of Toxoplasma gondii infection in pigs

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yongle Song ◽  
Yongjuan Zhao ◽  
Ke Pan ◽  
Bang Shen ◽  
Rui Fang ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Large Scale ◽  
Serological Test ◽  
Animal Health ◽  
Screening Tests ◽  
Enzyme Linked Immunosorbent Assay ◽  
Specific Method ◽  
Artificial Infection ◽  
Peptide Antigen ◽  
Diagnostic Kits

Abstract Background Toxoplasmosis caused by Toxoplasma gondii is a serious disease threatening human and animal health. People can be infected with T. gondii by ingesting raw pork contaminated with cysts or oocysts. Serological test is a sensitive and specific method usually used for large-scale diagnosis of T. gondii infection in humans and animals (such as pigs). Commercial pig Toxoplasma antibody ELISA diagnostic kits are expensive, which limits their use; moreover, the wide antigen composition used in these diagnostic kits is still unclear and difficult to standardize. The multiepitope peptide antigen is a novel diagnostic marker, and it has potential to be developed into more accurate and inexpensive diagnostic kits. Methods The synthetic multiepitope antigen (MAG) cDNA encoding a protein with epitopes from five T. gondii-dominant antigens (SAG1, GRA1, ROP2, GRA4, and MIC3) was designed, synthesized, and expressed in Escherichia coli BL21 (DE3) strain. The recombinant protein was detected through western blot with pig anti-T. gondii-positive and -negative serum, and then IgG enzyme-linked immunosorbent assay (ELISA) named MAG-ELISA was designed. The MAG-ELISA was evaluated in terms of specificity, sensitivity, and stability. The MAG-ELISA was also compared with a commercial PrioCHECK®Toxoplasma Ab porcine ELISA (PrioCHECK ELISA). Finally, the trend of pig anti-T. gondii IgG levels after artificial infection with RH tachyzoites was evaluated using MAG-ELISA and two other ELISA methods (rMIC3-ELISA and PrioCHECK ELISA). Results MAG antigen could be specifically recognized by pig anti-T. gondii-positive but not -negative serum. MAG-ELISA showed high diagnostic performance in terms of specificity (88.6%) and sensitivity (79.1%). MAG-ELISA could be used for detecting anti-T. gondii IgG in the early stage of T. gondii infection in pigs (at least 7 days after artificial infection). Conclusions Our results suggest that MAG antigen can be applied to specifically recognize anti-T. gondii IgG in pig, and MAG-ELISA has the potential for large-scale screening tests of T. gondii infection in pig farms and intensive industries. Graphical abstract

scholarly journals Characterization and Evaluation of a Recombinant Multiepitope Peptide Antigen MAG in the Serological Diagnosis of Toxoplasma Gondii Infection in Pigs

2021 ◽  
Author(s):  
Yongle Song ◽  
Yongjuan Zhao ◽  
Ke Pan ◽  
Bang Shen ◽  
Rui Fang ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Large Scale ◽  
Serological Test ◽  
Animal Health ◽  
Enzyme Linked Immunosorbent Assay ◽  
Specific Method ◽  
Peptide Antigen ◽  
Diagnostic Kits ◽  
Specificity And Sensitivity ◽  
Antibody Elisa

Abstract Background Toxoplasmosis caused by toxoplasma gondii (T. gondii) is a serious disease threatening human and animal health. People could be infected with T. gondii by ingesting raw pig meat contaminated with cysts or oocysts. Serological test is a sensitive and specific method usually used for large-scale diagnosis of T. gondii infection in humans and animals (such as pigs). Since commercial pig toxoplasma antibody ELISA diagnostic kits are too expensive, it is difficult to use them widely, moreover, the native antigen composition used in these diagnostic kits is still unclear and difficult to standardize. The multiepitope peptide antigen is novel diagnostic marker, and it has the potential to be developed into more accurate and inexpensive diagnostic kits. Methods The synthetic multiepitope antigen (MAG) gene encoding a protein with epitopes from 5 T. gondii dominant antigen (SAG1, GRA1, ROP2, GRA4, and MIC3) was designed, synthesized, and expressed in Escherichia coli BL21 (DE3) strain. The recombinant protein was detected through western blot with pig anti-T. gondii positive and negative serum, then IgG enzyme-linked immunosorbent assay (ELISA) named MAG-ELISA was designed. The MAG-ELISA was evaluated in terms of specificity, sensitivity, and stability. The MAG-ELISA was also compared with a commercial PrioCHECK® Toxoplasma Ab porcine ELISA (PrioCHECK ELISA). Finally, the trend of pig anti-T. gondii IgG level after artificially infection with RH tachyzoites was evaluated through MAG-ELISA and two other ELISA methods (rMIC3-ELISA and PrioCHECK ELISA). Results MAG antigen could be specifically recognized by pig anti-T. gondii positive but not negative serum. MAG-ELISA possessed a high diagnostic performance in terms of specificity and sensitivity. The overall coincidence rate between MAG-ELISA and a commercial PrioCHECK Toxoplasma antibody ELISA was 78.47%. MAG-ELISA could be used for detecting anti-T. gondii IgG in the early stage of T. gondii infection in pigs (at least 7 days after artificial infection). Conclusions Our results suggest that MAG antigen could be applied to specifically recognize anti-T. gondii IgG in pig, and MAG-ELISA has the potential for large-scale diagnosis of T. gondii infection in pig farms and intensive industries.

scholarly journals Detection of Anti-Toxoplasma gondii IgG and IgM Antibodies and Associated Risk Factors during Pregnancy in Southwest Iran

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Shahrzad Soltani ◽  
Ali Dalir Ghaffari ◽  
Mehdi Sagha Kahvaz ◽  
Mohamad Sabaghan ◽  
Marzieh Pashmforosh ◽  
...  
Keyword(s):  
Risk Factors ◽  
Toxoplasma Gondii ◽  
Pregnant Women ◽  
Cross Sectional Study ◽  
Screening Tests ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cross Sectional ◽  
Related Risk ◽  
Associated Risk Factors ◽  
Southwest Iran

Background. This research was aimed at evaluating the seroprevalence of acute and chronic Toxoplasma gondii (T. gondii) infection in pregnant women and related risk factors in southwest Iran. Methods. In this cross-sectional study, eighty-eight pregnant women were included from October 2019 to December 2019. The presence of anti-T. gondii IgM and IgG antibodies was measured using the enzyme-linked immunosorbent assay (ELISA). In addition, a questionnaire consisting of demographic information was completed for each subject. Results. The overall seroprevalence of T. gondii infection was estimated to be 34.09% (30/88). Of these, 1 (1.13%) and 29 (32.95%) samples were found positive for IgM and IgG, respectively. Regarding the risk factors, the consumption of raw/undercooked meat ( P value = 0.007) and history of abortion ( P value = 0.017) were significantly associated with IgG seroprevalence in pregnant women. Conclusion. The results showed that the pregnant women of southwest Iran might be moderately exposed to T. gondii. Since the risk of acute T. gondii infection in this susceptible group is very important, regular screening tests to diagnose the infection are recommended before pregnancy.

scholarly journals Seroepidemiological study of the exposure to Toxoplasma gondii among horses in Algeria and analysis of risk factors

2019 ◽  
Vol 12 (12) ◽  
pp. 2007-2016 ◽  
Author(s):  
Sabrine Fazia Ouslimani ◽  
Safia Tennah ◽  
Naouelle Azzag ◽  
Salima Yamina Derdour ◽  
Bernard China ◽  
...  
Keyword(s):  
Risk Factors ◽  
Toxoplasma Gondii ◽  
Coat Color ◽  
Fluorescent Antibody ◽  
Animal Health ◽  
Significant Risk ◽  
Reference Method ◽  
Latex Agglutination ◽  
Enzyme Linked Immunosorbent Assay ◽  
Toxoplasma Infection

Aim: The aim of this study was to assess the seroprevalence of the Toxoplasma gondii in horses in different parts of Algeria and to determine risk factors for the infection. Materials and Methods: A total of 736 blood samples were collected from horses of various breeds, gender, coat colors, and ages. All horses came from various farms, racecourses, and equestrian centers. The seroprevalence was investigated by three different methods: Indirect fluorescent antibody test (IFAT) as reference method, enzyme-linked immunosorbent assay (ELISA), and latex agglutination test (LAT). Results: Out of the 736 sera, 178 (24.18%) were positive for IFAT, 133 (18.07%) for LAT, and 317 (43.07%) for ELISA. It was found that IFAT and LAT were in high agreement (Kappa 0.79), indicating that LAT and IFAT had similar capabilities in the detection of anti-T. gondii antibodies from horse sera. Risk factors analysis based on IFAT results indicated that the habit of the animals was significant risk factors (p≤0.05) for Toxoplasma infection. The seroprevalence was significantly higher in horses living on farms. Moreover, a higher seroprevalence was found in older animals compared to younger ones. Furthermore, the seroprevalence in females was significantly higher than that in males and gelding. Breed, coat color, and water sources are also important factors to influence the seroprevalence of T. gondii. Conclusion: The results indicated that T. gondii is present in horses throughout Algeria and thus represents a risk for both human and animal health. These results underline the need to increase the vigilance and the preventive measures against this disease not only to protect the horses but also to limit the spread of the parasite.

scholarly journals Detection of Bovine Antibodies against a Conserved Capsid Epitope as the Basis of a Novel Universal Serological Test for Foot-and-Mouth Disease

2020 ◽  
Vol 58 (6) ◽  
Author(s):  
A. S. Asfor ◽  
N. Howe ◽  
S. Grazioli ◽  
S. Berryman ◽  
K. Parekh ◽  
...  
Keyword(s):  
Large Scale ◽  
Serological Test ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Enzyme Linked Immunosorbent Assay ◽  
Nonstructural Proteins ◽  
Fmd Virus ◽  
Foot And Mouth ◽  
Serological Surveillance ◽  
The Individual

ABSTRACT Diagnostic tests for foot-and-mouth disease (FMD) include the detection of antibodies against either the viral nonstructural proteins or the capsid. The detection of antibodies against the structural proteins (SP) of the capsid can be used to monitor seroconversion in both infected and vaccinated animals. However, SP tests need to be tailored to the individual FMD virus (FMDV) serotype and their sensitivity may be affected by antigenic variability within each serotype and mismatching between test reagents. As a consequence, FMD reference laboratories are required to maintain multiple type-specific SP assays and reagents. A universal SP test would simplify frontline diagnostics and facilitate large-scale serological surveillance and postvaccination monitoring. In this study, a highly conserved region in the N terminus of FMDV capsid protein VP2 (VP2N) was characterized using a panel of intertype-reactive monoclonal antibodies. This revealed a universal epitope in VP2N which could be used as a peptide antigen to detect FMDV-specific antibodies against all types of the virus. A VP2-peptide enzyme-linked immunosorbent assay (VP2-ELISA) was optimized using experimental and reference antisera from immunized, convalescent, and naïve animals (n = 172). The VP2-ELISA is universal and simple and provided sensitive (99%) and specific (93%) detection of antibodies to all FMDV strains used in this study. We anticipate that this SP test could have utility for serosurveillance during virus incursions in FMD-free countries and as an additional screening tool to assess FMD virus circulation in countries where the disease is endemic.

scholarly journals Comparison of agar gel immunodiffusion test, enzyme-linked immunosorbent assay and PCR in diagnostics of enzootic bovine leukosis

2005 ◽  
Vol 59 (3-4) ◽  
pp. 363-370
Author(s):  
Tadej Malovrh ◽  
M. Pate ◽  
M. Ocepek ◽  
B. Krt
Keyword(s):  
Antibody Response ◽  
Immunosorbent Assay ◽  
Large Scale ◽  
Serological Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Agar Gel ◽  
Bovine Leukaemia Virus ◽  
Leukaemia Virus ◽  
Elisa Kit ◽  
Pcr Method

Bovine leukaemia virus (BLV) is a retrovirus that induces a chronic infection in cattle. Once infected, cattle remain virus carriers for life and start to show an antibody response within a few weeks after infection. Eradication and control of the disease are based on early diagnostics and segregation of the carriers. The choice of a diagnostic method depends on the eradication programme, money resources and characteristics of the herd to be analysed. The agar gel immunodiffusion (AGID) test has been the serological test of choice for routine diagnosis of serum samples. Nevertheless, in more recent years, the enzyme-linked immunosorbent assay (ELISA) has replaced the AGID for large scale testing. For this purpose, commercially available BLV-ELISA kits were compared to the AGID and to the polymerase chain reaction (PCR) method performed with two sets of primers, amplifying env region. The ELISA kit based on the p24 core protein was found to be less specific and served as a screening test. The ELISA kit based on the envelope glycoprotein (gpSI) served as a verification test and gave a good correlation with the AGID test and PCR method. However, ELISA showed a higher sensitivity than AGID. The p24 based ELiSA was useful for screening a large number of samples, whereas gp51 based ELISA, AGID and PCR were more important for detecting the antibody response against the individual BLV-proteins and therefore for verification of the infection with BLV.

scholarly journals Seroprevalence and Associated Risk Factors of Toxoplasma Gondii Among Pregnant Women in Southwest Iran

2021 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Shahrzad Soltani ◽  
Ali Dalir Ghaffari ◽  
Mehdi Sagha Kahvaz ◽  
Mohamad Sabaghan ◽  
Marzieh Pashmforosh ◽  
...  
Keyword(s):  
Risk Factors ◽  
Toxoplasma Gondii ◽  
Pregnant Women ◽  
Immunoglobulin M ◽  
Screening Tests ◽  
Enzyme Linked Immunosorbent Assay ◽  
Seroprevalence Rate ◽  
Igm Antibodies ◽  
Associated Risk Factors ◽  
Southwest Iran

Background: Acute Toxoplasma gondii infection during pregnancy period can cause congenital toxoplasmosis. The aim of this study was to assess the seroprevalence rate of immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies against T. gondii infection during pregnancy and the associated risk factors in southwest Iran. Methods: This study was performed on 88 pregnant women from October to December 2019 in Khorramshahr County, Khuzestan province, Iran. Anti-T. gondii IgG and IgM antibodies were tested through enzyme-linked immunosorbent assay (ELISA) method. Results: Following serological assays, 38.63% (34/88) and 2.27% (2/88) serum samples were positive for IgG and IgM antibodies, respectively. Also, a statistically significant association was observed between IgG seroprevalence and drinking of unpurified water (P = 0.015). Conclusions: The serological evidence revealed that pregnant women of southwest Iran had moderate exposure to T. gondii parasite. Since the risk of acquiring acute toxoplasmosis in pregnant women is clinically important, we highly recommend regular screening tests for T. gondii infection during pregnancy period.

scholarly journals Thin Films Sensor Devices for Mycotoxins Detection in Foods: Applications and Challenges

Chemosensors ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 3 ◽  
Author(s):  
Andréia Santos ◽  
Andreia Vaz ◽  
Paula Rodrigues ◽  
Ana Veloso ◽  
Armando Venâncio ◽  
...  
Keyword(s):  
Thin Film ◽  
High Performance ◽  
Large Scale ◽  
Low Cost ◽  
Animal Health ◽  
High Sensitivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Film Sensor ◽  
Fast Analysis ◽  
Sensor Devices

Mycotoxins are a group of secondary metabolites produced by different species of filamentous fungi and pose serious threats to food safety due to their serious human and animal health impacts such as carcinogenic, teratogenic and hepatotoxic effects. Conventional methods for the detection of mycotoxins include gas chromatography and high-performance liquid chromatography coupled with mass spectrometry or other detectors (fluorescence or UV detection), thin layer chromatography and enzyme-linked immunosorbent assay. These techniques are generally straightforward and yield reliable results; however, they are time-consuming, require extensive preparation steps, use large-scale instruments, and consume large amounts of hazardous chemical reagents. Rapid detection of mycotoxins is becoming an increasingly important challenge for the food industry in order to effectively enforce regulations and ensure the safety of food and feed. In this sense, several studies have been done with the aim of developing strategies to detect mycotoxins using sensing devices that have high sensitivity and specificity, fast analysis, low cost and portability. The latter include the use of microarray chips, multiplex lateral flow, Surface Plasmon Resonance, Surface Enhanced Raman Scattering and biosensors using nanoparticles. In this perspective, thin film sensors have recently emerged as a good candidate technique to meet such requirements. This review summarizes the application and challenges of thin film sensor devices for detection of mycotoxins in food matrices.

scholarly journals Serological detection of avian reovirus in different poultry flocks of Gazipur and Mymensingh districts of Bangladesh

2019 ◽  
Vol 12 (7) ◽  
pp. 1126-1131 ◽  
Author(s):  
Syeda Farjana Neepa ◽  
Zobayda Farzana Haque ◽  
Abdullah Al Momen Sabuj ◽  
Md Alimul Islam ◽  
Sukumar Saha
Keyword(s):  
Large Scale ◽  
Serological Test ◽  
Age Groups ◽  
Vaccination Status ◽  
Enzyme Linked Immunosorbent Assay ◽  
Avian Reovirus ◽  
Wing Vein ◽  
Broiler Breeder ◽  
Blood Samples ◽  
Test Kit

Background and Aim: Avian reovirus (ARV) is a constraint to poultry industry in Bangladesh as a cause of several diseases in chickens, especially in broiler. However, the actual status of the viral infection is not known because the large-scale study is not conducted in this country. Therefore, this study aimed to check the presence and distribution of ARV-specific antibody in respect to area, types of chickens (broiler breeder, broiler, and layer), vaccination status, and age of chickens in Gazipur and Mymensingh districts of Bangladesh. Materials and Methods: A total of 276 chickens' blood samples were collected from two well-organized broiler breeder stock, seven broiler farms, and five layer farms located at two districts, namely Gazipur and Mymensingh of Bangladesh. Blood samples were collected from wing vein of the apparently healthy chickens using 3 ml of syringe and serum was harvested by keeping the syringe at room temperature in slanting position. The sera were transferred to the laboratory by maintaining the cool chain and further processing was performed by indirect enzyme-linked immunosorbent assay using ARV antibody test kit. Results: The results of serological test revealed that an average of 39.5% seropositive against ARV was recorded in chickens of Gazipur and Mymensingh districts. Among these, chickens of Gazipur district had the highest seropositivity of 50.5% than Mymensingh (30.7%). With respect to vaccination status, the seropositivity of vaccinated chickens in both areas was 100% and non-vaccinated chickens was 50.5% in Gazipur and 30.7% in Mymensingh district, respectively. However, regarding age groups, the seropositivity was higher in the age of 4-6 weeks (64.5%). Conclusion: The present serological findings showed a higher prevalence of ARV-specific antibodies in broiler birds. It indicates that the poultry industries of Bangladesh are contaminated with ARV which may naturally be transmitted to chickens either vertically or horizontally.

D-Dimer Determination to Exclude Pulmonary Embolism: a Two-Step Approach Using Latex Assay as a Screening Tool

1994 ◽  
Vol 72 (01) ◽  
pp. 089-091 ◽  
Author(s):  
P de Moerloose ◽  
Ph Minazio ◽  
G Reber ◽  
A Perrier ◽  
H Bounameaux
Keyword(s):  
Pulmonary Embolism ◽  
Screening Tool ◽  
Screening Tests ◽  
Enzyme Linked Immunosorbent Assay ◽  
Elisa Assay ◽  
Elisa Technique ◽  
Diagnostic Step ◽  
D Dimer ◽  
Rule Out ◽  
Latex Test

SummaryD-dimer (DD), when measured by a quantitative enzyme-linked immunosorbent assay (ELISA), is a valuable test to exclude venous thromboembolism (VTE). However, DD ELISA technique is not appropriate for emergency use and the available agglutination latex assays are not sensitive enough to be used as an alternative to rule out the diagnosis of VTE. Latex assays could still be used as screening tests. We tested this hypothesis by comparing DD levels measured by ELISA and latex assays in 334 patients suspected of pulmonary embolism. All but one patient with a positive (DD ≥500 ng/ml) latex assay had DD levels higher than 500 ng/ml with the ELISA assay. Accordingly, ELISA technique could be restricted to patients with a negative result in latex assay. This two-step approach would have spared about 50% of ELISA in our cohort. In conclusion, our data indicate that a latex test can be used as a first diagnostic step to rule out pulmonary embolism provided a negative result is confirmed by ELISA and the performance of the latex assay used has been assessed properly.

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