scholarly journals Diagnostic-test evaluation of immunoassays for anti-Toxoplasma gondii IgG antibodies in a random sample of Mexican population

2014 ◽  
Vol 8 (05) ◽  
pp. 642-647 ◽  
Author(s):  
Heriberto Caballero-Ortega ◽  
Rocío Castillo-Cruz ◽  
Sandra Murieta ◽  
Luz Belinda Ortíz-Alegría ◽  
Esther Calderón-Segura ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Western Blot ◽  
Latin American ◽  
High Sensitivity ◽  
Reference Standards ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Serological Tests ◽  
Western Blots ◽  
Open Population

Introduction: There are few articles on evaluation of Toxoplasma gondii serological tests. Besides, commercially available tests are not always useful and are expensive for studies in open population. The aim of this study was to evaluate in-house ELISA and western blot for IgG antibodies in a representative sample of people living in Mexico. Methodology: Three hundred and five serum samples were randomly selected from two national seroepidemiological survey banks; they were taken from men and women of all ages and from all areas of the country. ELISA cut-off was established using the mean plus three standard deviations of negative samples. Western blots were analysed by two experienced technicians and positivity was established according to the presence of at least three diagnostic bands. A commercial ELISA kit was used as a third test. Two reference standards were built up: one using concordant results of two assays leaving the evaluated test out and the other in which the evaluated test was included (IN) with at least two concordant results to define diagnosis. Results: the lowest values of diagnostic parameters were obtained with the OUT reference standards: in-house ELISA had 96.9% sensitivity, 62.1% specificity, 49.6% PPV, 98.1% NPV and 71.8% accuracy, while western blot presented 81.8%, 89.7%, 84.0%, 88.2% and 86.6% values and the best kappa coefficient (0.72-0.82). Conclusions: The in-house ELISA is useful for screening people of Mexico, due to its high sensitivity, while western blot may be used to confirm diagnosis. These techniques might prove useful in other Latin American countries.

scholarly journals Comparative evaluation of AxSYM, VIDAS and VIDIA toxoplasmosis reagent performance in a high seroprevalence Latin American country

2010 ◽  
Vol 20 (1) ◽  
pp. 27 ◽  
Author(s):  
Bernard Weber ◽  
Marisol Badiel ◽  
Yanet Alvarez-Otero ◽  
Philippe Thulliez ◽  
José G. Montoya
Keyword(s):  
Toxoplasma Gondii ◽  
Pregnant Women ◽  
Latin American ◽  
Latin American Country ◽  
Comparative Evaluation ◽  
High Sensitivity ◽  
Igg Antibodies ◽  
High Seroprevalence ◽  
Igm Antibodies

AIMS: The purpose of this study was to compare the performance of three automated immunoassays for the detection of IgM and IgG Toxoplasma gondii antibodies using sera of pregnant women living in Colombia, a Latin American country with a high seroprevalence. METHODS: A total of 905 sera were tested for IgM antibodies and 914 for IgG antibodies with AxSYM, VIDAS and VIDIA immunoassays. Discrepancies were resolved by using the dye test for IgG antibodies, and the ISAGA test for IgM. RESULTS: The overall agreement between AxSYM, VIDAS and VIDIA assays was excellent for detection of IgG and IgM antibodies, and discrepancies were relatively rare (3.6% and 5.5% of sera for IgG and IgM antibodies, respectively). The performance of the three immunoassays was similar for the detection of IgG antibodies with high sensitivity (100.00% for VIDIA, 99.59% for VIDAS, 99.38% for AxSYM) and specificity (99.04% for VIDIA, 98.82% for AxSYM, 98.57% for VIDAS). The specificity for IgM antibodies was excellent for the three immunassays (99.88% for VIDIA, 99.76% for AxSYM and VIDAS). The sensitivity of the detection of IgM antibodies was higher with VIDIA (95.12%) than with VIDAS (76.74%) and AxSYM (61.90%) assays. The correlation between IgG titers was limited between AxSYM and VIDAS assays and between AxSYM and VIDIA assays, but was excellent between VIDIA and VIDAS assays. CONCLUSIONS: Our study performed with Latin American sera confirmed the excellent specificity of AxSYM, VIDAS and VIDIA assays for the detection of IgG and IgM antibodies already reported in other countries. The sensitivity of the detection of IgG antibodies was slightly higher with VIDIA than with VIDAS and AxSYM assays. The sensitivity of the detection of IgM antibodies was higher with VIDIA than with VIDAS and AxSYM assays.

Serum Feline Pancreatic Lipase Immunoreactivity Concentration and Seroprevalences of Antibodies Against Toxoplasma Gondii and Bartonella Species in Client-Owned Cats

2009 ◽  
Vol 11 (8) ◽  
pp. 663-667 ◽  
Author(s):  
Danielle B. Bayliss ◽  
Jörg M. Steiner ◽  
Jan S. Sucholdolski ◽  
Steven V. Radecki ◽  
Melissa M. Brewer ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Immunosorbent Assay ◽  
Pancreatic Lipase ◽  
Clinical Findings ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Bartonella Species ◽  
Serum Samples ◽  
Serological Tests ◽  
Ig G

Feline pancreatitis is a commonly suspected illness and it has been proposed that some cases of feline pancreatitis may be caused by infection with Toxoplasma gondii or Bartonella species. Feline pancreatic lipase immunoreactivity (fPLI) is a test performed on serum that is commonly combined with other clinical findings as an indirect aid in the diagnosis of pancreatitis. The purpose of this study was to determine if there are associations between fPLI concentration and the presence of serum antibodies against T gondii or Bartonella species. Serum samples from 458 cats, for which serum fPLI concentrations had already been determined, were assayed by enzyme-linked immunosorbent assay for the presence of T gondii immunoglobulin (Ig) G (IgG) and IgM antibodies, and Bartonella species IgG antibodies. The association between fPLI concentration and T gondii or Bartonella species antibodies was determined. No statistically significant association was found between fPLI concentration and T gondii or Bartonella species antibodies, suggesting that serological tests for the organisms are not useful in cases with increased fPLI concentration.

scholarly journals Recombinant Dense Granular Protein (GRA5) for Detection of Human Toxoplasmosis by Western Blot

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Xiao Teng Ching ◽  
Yee Ling Lau ◽  
Mun Yik Fong ◽  
Veeranoot Nissapatorn ◽  
Hemah Andiappan
Keyword(s):  
Western Blot ◽  
Affinity Purification ◽  
Expression System ◽  
Economic Loss ◽  
Serum Samples ◽  
Serological Tests ◽  
Human Patient ◽  
Prokaryotic Expression System ◽  
Human Sera ◽  
Lysate Antigens

Toxoplasma gondiiinfects all warm-blooded animals, including humans, causing serious public health problems and great economic loss for the food industry. Commonly used serological tests require costly and hazardous preparation of wholeToxoplasmalysate antigens from tachyzoites. Here, we have evaluated an alternative method for antigen production, which involved a prokaryotic expression system. Specifically, we expressedT. gondiidense granular protein-5 (GRA5) inEscherichia coliand isolated it by affinity purification. The serodiagnostic potential of the purified recombinant GRA5 (rGRA5) was tested through Western blot analysis against 212 human patient serum samples. We found that rGRA5 protein was 100% specific for analysis of toxoplasmosis-negative human sera. Also, rGRA5 was able to detect acute and chronicT. gondiiinfections (sensitivities of 46.8% and 61.2%, resp.).

A Preliminary Evaluation of a Prototype Western Blot Confirmatory Test Kit for Syphilis

1994 ◽  
Vol 5 (6) ◽  
pp. 409-414 ◽  
Author(s):  
H Young ◽  
P J Walker ◽  
D Merry ◽  
A Mifsud
Keyword(s):  
Western Blot ◽  
False Positive ◽  
High Sensitivity ◽  
High Specificity ◽  
Confirmatory Test ◽  
Preliminary Evaluation ◽  
Serological Tests ◽  
Western Blot Test ◽  
Specificity And Sensitivity ◽  
Test Kit

A prototype Western blot kit was evaluated as a confirmatory test for syphilis using 131 sera characterized by other serological tests for syphilis. There were 114 treponemal sera (including 94 cases of early syphilis, 83 of which were untreated) and 17 non-treponemal problem sera (11 gave false positive reactions on screening with the TmpA recombinant antigen enzyme immunoassay (EIA), 3 gave false positive fluorescent treponemal antibody absorbed (FTA-abs) tests, and 3 false positive Captia Syphilis G EIA results). Based on the manufacturer's criteria of reactivity in multiple bands for designating a positive result the Western blot test gave a sensitivity of 99.1% (113/114) and a specificity of 88.2% (15/17) when indeterminate reactions were scored positive and 98.2% (112/114) and 100% (17/17) when indeterminate reactions were scored negative. Sensitivity was high in both treated and untreated infection. Corresponding sensitivities for the TPHA and FTA-abs when equivocal reactions were scored negative were 97.5% (111/114) and 99.1% (113/114). The high sensitivity of the FTA-abs in this study is probably due to the large number of untreated primary infections. Our results with the Western blot, confirm earlier studies using ‘in-house’ test systems and, support a role for a commercial Western blot test in the confirmatory diagnosis of syphilis. Further studies are required to confirm the high specificity and sensitivity of the kit in a larger series including a wider variety of non-treponemal cases as well as patients with untreated and treated infection.

scholarly journals Comparison of Coombs Gel Test with ELISA and Standard Tube Agglutination Tests Used in Serological Diagnosis of Brucellosis

2020 ◽  
Vol 2 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Cigdem Akalan Kuyumcu ◽  
Serpil Erol ◽  
Rıza Adaleti ◽  
Seniha Senbayrak ◽  
Secil Deniz ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Diagnostic Tests ◽  
Serological Test ◽  
High Sensitivity ◽  
Serological Diagnosis ◽  
Control Groups ◽  
Serum Samples ◽  
Serological Tests ◽  
Reliable Test ◽  
And Control

Objective: Serological tests are the most commonly used tests in the diagnosis of brucellosis; however, each serological test has some drawbacks. In this study, we aimed to determine the value of the Brucella Coombs gel test (BCGT) in the serological diagnosis of brucellosis in comparison with Standard tube agglutination (STA) and ELISA tests. Materials and Methods: The study included 42 patients who were considered to have brucellosis as a preliminary diagnosis. BCGT, Brucella-IgM/IgG ELISA, and STA tests were performed from serum samples of the patients. The correlation of the diagnostic tests was analyzed using Cohen’s Kappa Analysis.  Results: Twenty-seven (64.2%) of 42 patients were diagnosed with brucellosis according to their medical history and clinical and serological tests. The sensitivity and specificity of BCGT to diagnose brucellosis was 96.2%, and 100%, respectively. The sensitivity and specificity for the diagnosis of brucellosis 62.9% and 100% for STA, respectively; 33.3% and 66.6% for Brucella-IgM; and 66.6% and 100% for Brucella-IgG. BCGT was significantly correlated with STA (κ= 0.590) and Brucella-IgG (κ=0.539) Conclusion: BCGT can be utilized as a simple and reliable test in the diagnosis of brucellosis with high sensitivity and specificity. Nevertheless, the sensitivity and specificity of BCGT should be demonstrated by comprehensive studies, including culture-confirmed cases and control groups.

Seroprevalence of human Taenia solium cysticercosis in Haiti

2009 ◽  
Vol 83 (2) ◽  
pp. 113-116 ◽  
Author(s):  
C.P. Raccurt ◽  
P. Agnamey ◽  
J. Boncy ◽  
J.-H. Henrys ◽  
A. Totet
Keyword(s):  
Public Health ◽  
Developing Countries ◽  
Latin American ◽  
Taenia Solium ◽  
Public Health Problem ◽  
Sub Saharan Africa ◽  
Serum Samples ◽  
African Countries ◽  
Cross Sectional ◽  
Western Blots

AbstractHuman Taenia solium cysticercosis is common in developing countries due to poor sanitary conditions and economics based on breeding livestock, especially pigs, with low hygiene standards. Neurocysticercosis, caused by migration of the larvae of the tapeworm in the nervous system, is the leading cause of acquired epilepsy in adults in Central and South America, sub-Saharan Africa, and East and South Asia. This makes neurocysticercosis a large public health problem in developing countries. Two clinical cases of neurocysticercosis have been observed recently in Haiti. In order to evaluate the prevalence of human T. solium cysticercosis in this country, in 2007 we conducted a cross-sectional serological retrospective survey using a Western blotting test (LDBIO Diagnostics®) in Port-au-Prince, where sewage systems are rare and swine usually roam freely throughout the area. A total of 216 serum samples, obtained from healthy adults seen in the work setting of periodical medical visits, were tested after storage at − 20°C. The frequency of antibodies in serum samples of the study population was 2.8% (6/216). The immunodominant bands recognized in Western blots were 23–26 kDa (100%), 39 kDa (67%), 45 kDa and 6–8 kDa (50%), 50–55 kDa (33%). These results confirm for the first time an endemic situation of cysticercosis in humans in Haiti, with similar prevalence as that reported in other Latin American and African countries. It reinforces the urgent need for control and prevention measures to be taken by local public health services.

scholarly journals Use of GRA6-Derived Synthetic Polymorphic Peptides in an Immunoenzymatic Assay To Serotype Toxoplasma gondii in Human Serum Samples Collected from Three Continents

2008 ◽  
Vol 15 (9) ◽  
pp. 1380-1386 ◽  
Author(s):  
Susana Sousa ◽  
Daniel Ajzenberg ◽  
Manuel Vilanova ◽  
José Costa ◽  
Marie-Laure Dardé
Keyword(s):  
Toxoplasma Gondii ◽  
Latin American ◽  
Enzyme Linked Immunosorbent Assay ◽  
Clear Correlation ◽  
Type I ◽  
Serum Samples ◽  
Typing Method ◽  
Microsatellite Genotype ◽  
Human Infections ◽  
Immunoenzymatic Assay

ABSTRACT Serotyping is a simple typing method that consists of an immunoenzymatic assay (enzyme-linked immunosorbent assay [ELISA]) using synthetic polymorphic peptides derived from Toxoplasma gondii antigens. We developed a new ELISA based on GRA6 C-terminal polymorphic peptides. Serum samples from 41 human infections due to 23 archetypal (type I, II, or III) and 18 nonarchetypal strains were selected in order to validate this approach. For 20 out of the 23 archetypal infections, there was a clear correlation between microsatellite genotype and GRA6 serotyping. All infections due to nonarchetypal strains were misclassified as archetypal strain infections. The GRA6 C-terminal peptides from these strains were analyzed to explain this misclassification. A second group of 455 patients with acute and chronic toxoplasmosis due to unknown genotypes from different European, African, and Latin American countries were included in this study, and the strain type predicted by this method. The results suggest that serotyping is a promising method for typing strains, although limitations exist for African and South American strains as a consequence of higher peptide polymorphism. Other peptides from different markers must be studied in order to discriminate archetypal from nonarchetypal strains.

scholarly journals Western Blot Analysis of the IgG-Antibody Response to Acid- Glycine-Extracted Antigens from Campylobacter fetus subsp. fetus and C. jejuni in Naturally Infected Sheep

2007 ◽  
Vol 76 (2) ◽  
pp. 245-251 ◽  
Author(s):  
K. Gürtürk ◽  
I. H. Ekin ◽  
A. Arslan
Keyword(s):  
Antibody Response ◽  
Western Blot ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Serological Tests ◽  
Recent Infection ◽  
Healthy Sheep ◽  
Apparently Healthy

IgG-antibody response in aborting sheep and in apparently healthy sheep in a flock against acidglycine- extracted antigens from three strains for each C. fetus subsp. fetus and C. jejuni were analysed by Western blot. One strain of C. fetus subsp. fetus was isolated from aborting sheep. Western blot analysis of the sera revealed the presence of IgG antibody binding to the common antigens including proteins with the Mw of 63 kDa and 54 kDa in extracts from both C. fetus subsp. fetus and C. jejuni strains. In addition, IgG antibodies in sera from aborting sheep reacted more strongly with the antigens from C. fetus subsp. fetus strains with Mw of approximately 100, 95 and 86.5 kDa than those of apparently healthy sheep. The binding profile of the antibodies with these antigens appeared to be unique for each C. fetus subsp. fetus strain. On the other hand, IgG antibodies only in sera from aborting sheep recognized strongly the antigens of each C. fetus subsp. fetus strain at the Mw ranged from approximately 26 to 22 kDa. However, the antigenic components between 26 and 22 kDa were not detectable in coomassie blue stained gel and thought to have non-protein nature. These low molecular weight antigens of C. fetus subsp. fetus may be related to a recent infection in aborting sheep. These observations indicate that such speciesspecific antigens or conjugated protein antigens could be used for improving the specificity of the serological tests to detect C. fetus antibodies in sheep sera, and may be the candidates for subunit vaccines against ovine abortion.

scholarly journals Serological evidence and factors associated with porcine toxoplasmosis in three villages of Fara’s division in Burkina Faso

2020 ◽  
Vol 14 (6) ◽  
pp. 2172-2180
Author(s):  
Laibané Dieudonné Dahourou ◽  
Oubri Bassa Gbati ◽  
Arnaud Rayangnéwêndé Stéphane Tapsoba ◽  
Saandi Moina Riziki ◽  
Amadou Traore
Keyword(s):  
Toxoplasma Gondii ◽  
Burkina Faso ◽  
Associated Factors ◽  
Indirect Elisa ◽  
Multivariate Logistic Regression Model ◽  
Igg Antibodies ◽  
Multivariate Logistic Regression ◽  
Serological Evidence ◽  
Serum Samples ◽  
Factors Associated

Porcine toxoplasmosis is a worldwide zoonosis. This study was conducted to establish evidence of toxoplasmosis and its associated factors among pigs in three villages of Balés province, Burkina Faso. Serums samples were collected from 182 pigs and data was collected on farmers’ sociodemographics, origin (village) of pigs, pigs’ sex, age, breed and keeping systems through a household questionnaire interview. Serum samples were analyzed using indirect ELISA targeting IgG antibodies to Toxoplasma gondii. Results of the study showed an overall sero-prevalence of 16.5 % (95% CI: 11.1% – 21.9%). The sero-prevalence was higher in Toné (23.1%; 95% CI: 12.8% – 33.3%) and Kabourou (20.7%; 95% CI: 10.3% – 31.1%) compared to Sadon Bobo (5.1%; 95% CI: 0% – 10.7%) (p=0.01). It was also higher in pigs older than 12 months (23.2%; 95% CI: 14.9% – 31.5%) compared to pigs less than 12 months (8.4%; 95% CI: 02.4% – 14.4%) (p=0.00731). During rainy season, tethered pigs (7.1%; CI95: 0.40% – 13.8%) were less infected than housed pigs (20.6%; 95% CI: 11.1% – 21.9%) (p=0.02). Multivariate logistic regression model shows that pigs older than 12 months were more likely to get infected compared to pigs less than 12 months old (OR = 2.58; 95% CI = 1.00 - 6.62; p=0.04). These results provided evidence for the presence of T. gondii in pigs in this area.Keywords: Burkina Faso, pigs, Toxoplasma gondii, seroepidemiological studies, zoonosis.  

scholarly journals Fluorescent bead-based serological detection of Toxoplasma gondii infection in chickens

2020 ◽  
Author(s):  
Benedikt T. Fabian ◽  
Fatima Hedar ◽  
Martin Koethe ◽  
Berit Bangoura ◽  
Pavlo Maksimov ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Small Ruminants ◽  
High Sensitivity ◽  
Negative Control ◽  
Immunofluorescence Assay ◽  
Farm Animals ◽  
Serological Tests ◽  
Modified Agglutination Test ◽  
Magnetic Capture ◽  
Luminex Technology

Abstract Background: Free-ranging chickens are often infected with Toxoplasma gondii. Their infection indicates environmental contamination with T. gondii. The detection of infected birds relies primarily on serological assays. Methods: Here, we established a bead-based multiplex assay (BBMA) using the Luminex technology for the specific and sensitive detection of T. gondii infections in chickens. Recombinant biotinylated T. gondii surface antigen 1 (TgSAG1bio) bound to streptavidin-conjugated magnetic Luminex beads served as antigen. Serum antibodies were detected by a fluorophore-coupled secondary antibody. Beads of differing color codes were conjugated with anti-chicken IgY or chicken serum albumin and served for each sample as an internal positive or negative control, respectively. The assay was validated with sera from experimentally and naturally infected chickens. The results were compared to those from reference methods, including other serological tests and bioassay in mice.Results: In experimentally infected chickens, the vast majority (98.5%, n=65/66) of inoculated birds tested seropositive in the BBMA. This included all chickens positive by magnetic-capture PCR (100%, n=45/45). Most, but not all inoculated and TgSAG1bio-BBMA-positive chickens were also positive in two previously established TgSAG1-ELISAs (TgSAG1-ELISASL, n=61/65; or TgSAG1-ELISASH, n=60/65), or positive in an immunofluorescence assay (IFAT, n=64/65)) and in a modified agglutination test (MAT, n=61/65). All non-inoculated control animals (n=28/28, 100%) tested negative. In naturally exposed chickens, the TgSAG1bio-BBMA showed a high sensitivity (98.5%; 95% Confidence Interval: 90.7-99.9%) and specificity (100%; 85.0-100%) relative to a reference standard established using ELISA, IFAT and MAT. Almost all naturally exposed chickens that were positive in bioassay or by PCR tested positive in the TgSAG1bio-BBMA (93.5%; 77.1-98.9%), while all bioassay- or PCR-negative chickens remained negative (100%; 85.0-100%).Conclusions: The TgSAG1bio-BBMA represents a suitable method for the detection of T. gondii infections in chickens with high sensitivity and specificity, which is comparable or even superior to other tests. Since assays based on this methodology allow for the simultaneous analysis of a single biological sample with respect to multiple analytes, the described assay may represent one component in future multiplex assays for broad serological monitoring of poultry and other farm animals, including pigs or small ruminants, for various pathogens.

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