scholarly journals Evaluation of antigenic variations between two virulent toxoplasma strains

2006 ◽  
Vol 55 (10) ◽  
pp. 1333-1335 ◽  
Author(s):  
Songul Bayram Delibas ◽  
Hatice Ertabaklar ◽  
Sema Ertug

Toxoplasma gondii infection in humans is routinely assessed by serological means. Here, the authors attempted to compare the response of different Toxoplasma strains to serological tests and to evaluate the antigenic profiles of the RH and RH Ankara (TRH) strains with Western blotting. Anti-Toxoplasma IgG antibodies of 72 patients were examined with the indirect immunofluorescence antibody (IFA) test, ELISA and Western blotting (WB) by using antigen from both strains. Antigenic variations between strains did not affect IFA and ELISA test results, but qualitative and quantitative differences between the WB patterns were observed. A number of bands with molecular masses varying between 17 and 105 kDa were detected in WB. Fourteen different bands were obtained with the assay performed with RH strain antigen. An additional four bands were observed with TRH strain antigen. Also, an 80 kDa band was observed to stain darker in the blot with TRH strain antigen, whereas with RH strain antigen 30 and 38 kDa bands were darker. The results showed that strain-specific polymorphism in tachyzoite antigens of different Toxoplasma strains is important in the evaluation of WB but not in conventional serological analyses such as ELISA and IFA.

2010 ◽  
Vol 7 (2) ◽  
pp. 901-909
Author(s):  
Baghdad Science Journal

Five serological methods for detection of Brucella were compaired in this study, Four of the methods are commonely used in the detections:- 1-Rose-Bengal: as primary screening test which depends on detecting antibodies in the blood serum. 2-IFAT: which detects IgG and IgM antibodies in the serum. 3-ELISA test: which detects IgG antibodies in the serum. 4-2ME test: which detects IgG antibodies The fifth methods. It was developed by a reasercher in one of the health centers in Baghdad. It was given the name of spot Immune Assay (SIA). Results declares that among (100) samples of patients blood, 76, 49, 49, 37, and 28. samples were positive to Rose Bengal, ELISA, SIA, 2ME and IFAT tests, respectively. When efficiency, sensitivity and specificity of the serological methods were compaired, the Following results were obtained: a) ELISA and SIA were superiors among the other confirming methods (2ME and IFAT) in detecting the highest cases (49 cases); 46 of them were from the (76) cases positive to Rose Bengal The confirmatory test 2ME was not efficient in detecting low concentrations of IgG antibodies when less than half (37) of the total positive cases (76) were detected by this test. b) IFAT test was the least efficient confirmatory test among all other test. c) As a new confirmatory test, SIA proved to be an efficient and serological test for Brucella detection in comparison with other tests. It is an easy to use test, rapid and could be performed without need to the expensive equipment .


2014 ◽  
Vol 8 (05) ◽  
pp. 642-647 ◽  
Author(s):  
Heriberto Caballero-Ortega ◽  
Rocío Castillo-Cruz ◽  
Sandra Murieta ◽  
Luz Belinda Ortíz-Alegría ◽  
Esther Calderón-Segura ◽  
...  

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.


2020 ◽  
Vol 58 (8) ◽  
pp. 1357-1364 ◽  
Author(s):  
Marie Tré-Hardy ◽  
Alain Wilmet ◽  
Ingrid Beukinga ◽  
Jean-Michel Dogné ◽  
Jonathan Douxfils ◽  
...  

AbstractObjectivesFaced with the COVID-19 pandemic and its impact on the availability and quality of both therapeutic and diagnostic methods, the Belgian authorities have decided to launch a procedure for additional evaluation of the performance of serological tests offered for sale on the national territory. This has been proposed with a double aim: (1) an in-depth verification of the analytical and clinical performances presented by the manufacturer and (2) an economy of scale in terms of centralized validation for all the laboratories using the tests subject to evaluation.MethodsA retrospective validation study was conducted including the serum of 125 patients in order to determine the analytical and clinical performances of the LIAISON®SARS-CoV-2 from DiaSorin® detecting anti-SARS-CoV-2 IgG and to compare its clinical performance with the enzyme-linked immunosorbent assay (ELISA) test from Euroimmun®, one of the first commercially available tests allowing the detection of anti-SARS-CoV-2 IgA and IgG.ResultsThe performances of the LIAISON®SARS-CoV-2 satisfied all the acceptance criteria and provided “real world” analytical and clinical performances very close to the ones reported by the manufacturer in its insert kit. Comparison between the LIAISON®SARS-CoV-2 and the ELISA method did not reveal any difference between the two techniques in terms of sensitivities and specificities regarding the determination of the IgG.ConclusionsThis study reports the validation of the LIAISON®SARS-CoV-2 allowing to detect IgG antibodies specifically directed against SARS-CoV-2. The analytical and clinical performances are excellent, and the automation of the test offers important rates, ideal for absorbing an extension of testing.


2016 ◽  
Vol 13 (4) ◽  
pp. 714-720
Author(s):  
Baghdad Science Journal

Toxoplasma gondii has a worldwide distribution and it is one of the most prevalent infectious agents in Iraq. The study was conducted on 200 serum samples of unmarried female university of students age ranged between 18 to 26 years to detect Toxoplasma gondii antibodies. The aim of this study was to detect T. gondii antibodies among unmarried female students in Iraqi universities using different serological tests. Seventy six (38%) serum samples out of 200 subjects were positive for toxoplasma antibodies by Latex agglutination test (LAT). Among 76 LAT sera positive ,only 58 (29%) serum samples were positive with toxoplasma IgG ELISA test , however , the results of IgM ELISA assay were positive only for 3 (1.5%) unmarried female sample .None of negative LAT serum samples gave positive results with neither IgG nor IgM ELISA.


2018 ◽  
Vol 62 (4) ◽  
pp. 477-483 ◽  
Author(s):  
Angelina Wójcik-Fatla ◽  
Jacek Sroka ◽  
Violetta Zając ◽  
Jacek Zwoliński ◽  
Anna Sawczyn-Domańska ◽  
...  

AbstractIntroduction: Exposure to zoonotic factors in veterinary practice is closely related to the nature of the work. The main aim of the study was to determine the risk of selected zoonotic infections among the occupational group of veterinarians in Poland.Material and Methods: Blood samples of 373 veterinarians (162 males and 211 females) from 12 provinces of Poland were collected by the venipuncture of a forearm for serological tests. Commercial immunoenzymatic tests (ELISA) were used for detection of specific IgG antibodies to Echinococcus granulosus, IgM and IgG to Leptospira spp., and IgM, IgA, and I and II phase IgG to Coxiella burnetii. Enzyme-linked fluorescence assays (ELFA) were used to detect IgM and IgG antibodies to Toxoplasma gondii.Results: Positive results were found in 209 (56.0%) veterinarians for at least one of the examined diseases. The overall proportion of participants found to have specific Toxoplasma gondii antibodies in the IgM and/or IgG assays amounted to 44.5%. The presence of Coxiella burnetii antibodies was found in 16 (4.3%) subjects, while Leptospira spp. antibodies were detected in 63 (16.9%) veterinarians. Among the 373 veterinarians examined, no Echinococcus granulosus antibodies were found.Conclusion: Results of the study seem to indicate a slightly elevated risk of Toxoplasma gondii infection and a moderate risk of infection with Leptospira spp. and Coxiella burnetii in veterinarians.


2009 ◽  
Vol 11 (8) ◽  
pp. 663-667 ◽  
Author(s):  
Danielle B. Bayliss ◽  
Jörg M. Steiner ◽  
Jan S. Sucholdolski ◽  
Steven V. Radecki ◽  
Melissa M. Brewer ◽  
...  

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.


1999 ◽  
Vol 82 (11) ◽  
pp. 1412-1416 ◽  
Author(s):  
Wojciech Zareba ◽  
John Horan ◽  
Arthur Moss ◽  
Joel Kanouse ◽  
◽  
...  

SummaryOur previous prospective study of post-infarction patients described a strong and significant association of increased plasma D-dimer concentrations in those who experienced a subsequent coronary death or non-fatal myocardial infarction. In the present study, we compare results on stored plasma obtained two months after the index myocardial infarction from 1,038 patients of this trial, using a simple automated latex agglutination (LA) assay in parallel with the standard ELISA test. Results show a somewhat higher mean value for the LA assay (702 ± 1092 vs. 638 ± 986 ng/ml, p = 0.0002), a strong linear correlation of the two assays (r = 0.86) and 88% agreement for values below 500 ng/ml by the ELISA test. D-dimer concentrations determined by each assay were highly correlated in patients with subsequent coronary artery events (p = 0.93) and quartile values for both the LA and ELISA were equally predictive of such events (p = 0.003 and p = 0.001, respectively). This is the first demonstration that a latex agglutination assay for D-dimer can be used to assess the prognostic risk of recurrent coronary thrombotic disease after myocardial infarction


Author(s):  
Jasem Saki ◽  
Karim Mowla ◽  
Reza Arjmand ◽  
Forough Kazemi ◽  
Somayeh Fallahizadeh

Introduction: Parasitic myositis is caused by some parasites such as T. gondii and T. canis. So, the aim of the study was to evaluate the prevalence T. gondii and T. canis in patients with myositis and healthy individuals. Methods: A total of 108 samples were randomly selected as the control (54 healthy individuals) and test (54 myositis patients) groups. IgG and IgM antibodies against T. gondii and IgG antibodies against T. canis were measured by the ELISA. The detection of chronic and acute toxoplasmosis was performed by the ELISA IgG avidity. The presence of T. gondii in blood was evaluated by the nested-PCR. Results: Of 108, 33 (30.6%) cases were detected positive for IgG against T. gondii that 19 (35.2%) and 14 (25.9%) were observed in myositis patients and healthy individuals, respectively (P=0.296). Of 19 positive cases, 12 (63.2%) and 7 (36.8%) cases were detected as chronic and acute toxoplasmosis, respectively, while, all positive cases in the control group had chronic toxoplasmosis (P=0.013). One (1.9%) sample was detected positive for anti- Toxoplasma gondii IgM and two (3.7%) samples were found positive for IgG against T. canis by the ELISA that these positive cases were observed only in myositis patients (P=1.000 P=0.495, respectively). B1 T. gondii gene was amplified in 12 (63.2%) and 1 (7.1%) in myositis patients and healthy subjects (P=0.001). Conclusions: Our findings showed that there was a relatively high prevalence of acute toxoplasmosis in myositis patients in comparison with the control subjects in southwest of Iran.


2021 ◽  
Vol 9 (5) ◽  
pp. 1097
Author(s):  
Labrini V. Athanasiou ◽  
Vasileios G. Papatsiros ◽  
Victoria M. Spanou ◽  
Eleni G. Katsogiannou ◽  
Anna Dedousi

Neospora caninum and Toxoplasma gondii affect both humans and animals worldwide. To investigate their seroprevalence and differences in seropositivity between pigs vaccinated and unvaccinated against porcine circovirus 2 (PCV2), as well as differences in muscle enzyme activity between seropositive and seronegative pigs, blood samples were collected from 380 sows. Antibodies against T. gondii and N. caninum were detected by an indirect immunofluorescence antibody (IFA) assay, while the activities of creatine kinase (CK) and aspartate aminotransferase (AST) were biochemically assessed. Out of the 364 sows finally included in the study, 4.4%, 3.5%, and 0.5% were seropositive to T. gondii, N. caninum, or both. A significantly higher percentage of seropositivity against T. gondii and/or N. caninum in PCV2 unvaccinated pigs compared with vaccinated pigs was observed. Increased serum activities of CK and AST were detected in 71.43% and 100% of only against T. gondii (T+) and 63.64% and 90.91% of only against N. caninum (N+) seropositive sows, respectively, and were significantly higher compared to seronegative animals. T. gondii and N. caninum seropositivity, especially in presumed immunocompromised pigs, and the evidence of muscle damage highlight their importance as a zoonotic pathogen and animal model of human infection, respectively.


2021 ◽  
pp. postgradmedj-2021-140176
Author(s):  
Bahar Hassanmirzaei ◽  
Zohreh Haratian ◽  
Ali Ahmadzadeh Amiri ◽  
Amir Ahmadzadeh Amiri ◽  
Navid Moghadam

Purpose of the studyPCR is the current standard test for the diagnosis of SARS-CoV-2 infection. However, due to its limitations, serological testing is considered an alternative method for detecting SARS-CoV-2 exposure. In this study, we measured the level of SARS-CoV-2 IgM and IgG antibodies of male professional football players and compared the results with the standard PCR test to investigate the association between the two tests.Study designParticipants were male professional football players and team officials. Nasopharyngeal swabs and peripheral blood samples were collected for the PCR and serological tests, respectively. Also, previous records of COVID-19 testing and symptoms were gathered. Those with previous positive PCR tests who tested negative for the second time were considered to be recovered patients.ResultsOf the 1243 subjects, 222 (17.9%) were seropositive, while 29 (2.3%) tested positive for the SARS-CoV-2 PCR test. Sixty percent of symptomatic cases with a negative PCR were found to be seropositive. The mean level of IgM was significantly higher in PCR-positive and symptomatic subjects, whereas the recovered cases showed significantly higher levels of IgG.ConclusionOur study revealed an inconsistency of results between the two tests; therefore, although application of serological assays alone seems insufficient in diagnosing COVID-19 disease, the findings are beneficial in the comprehension and the management of the disease.


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