scholarly journals Taenia saginata Metacestode Antigenic Fractions without Affinity to Concanavalin A Are an Important Source of Specific Antigens for the Diagnosis of Human Neurocysticercosis

2010 ◽  
Vol 17 (4) ◽  
pp. 638-644 ◽  
Author(s):  
Heliana B. Oliveira ◽  
Gleyce A. Machado ◽  
José R. Mineo ◽  
Julia M. Costa-Cruz
Keyword(s):  
Sensitivity And Specificity ◽  
Concanavalin A ◽  
Taenia Solium ◽  
Specific Antigen ◽  
Enzyme Linked Immunosorbent Assay ◽  
Taenia Saginata ◽  
Serum Samples ◽  
Unbound Fraction ◽  
Immunoblot Assay ◽  
Homologous Antigen

ABSTRACT Taenia saginata metacestode antigens have been constituted a useful alternative antigen for neurocysticercosis (NC) serodiagnosis, particularly due to an increasing difficulty to obtain Taenia solium homologous antigen. Cross-reactivity with Echinococcus granulosus infection occurs in homologous and heterologous antigens and could be avoided by using different purified methods. The present study evaluated antigen fractions obtained from saline extracts of T. saginata metacestodes purified by affinity chromatography with jacalin or concanavalin A (ConA) lectins to detect IgG antibodies by enzyme-linked immunosorbent assay (ELISA) and immunoblot analysis to diagnose human NC. Serum samples were collected from 142 individuals: 40 of them were diagnosed with NC, 62 presented Taenia sp. and other parasites, and 40 were apparently healthy individuals. The jacalin- and ConA-unbound fractions demonstrated sensitivity and specificity higher than those of bound fractions. Among unbound fractions, ConA demonstrated statistically higher sensitivity and specificity by ELISA (90% and 93.1%, respectively). By immunoblot assay, the 64- to 68-kDa component from the ConA-unbound fraction showed 100% sensitivity and specificity, making this component suitable for use as a specific antigen for diagnosis of NC. To our knowledge, this is the first report showing the relevance of using the unbound ConA fraction of T. saginata metacestodes to diagnose NC. In conclusion, the results obtained herein clearly demonstrate that antigenic fractions without affinity to ConA, obtained from T. saginata metacestodes, are an important source of specific peptides and are efficient in the diagnosis of NC when tested by immunoblot assay.

scholarly journals Molecular characterization and diagnostic potential of serine proteinase inhibitors from Taenia solium

2017 ◽  
Vol 3 ◽  
Author(s):  
Guangxue Liu ◽  
Panhong Liang ◽  
Li Mao ◽  
Shaohua Zhang ◽  
Lijie Wang ◽  
...  
Keyword(s):  
Proteinase Inhibitors ◽  
Taenia Solium ◽  
Specific Antigen ◽  
Serine Proteinase ◽  
Bioinformatic Analysis ◽  
Enzyme Linked Immunosorbent Assay ◽  
Reaction Centre ◽  
Serum Samples ◽  
Diagnostic Potential ◽  
Wide Range

Abstract Serine protease inhibitors (serpins) play essential physiological roles in a wide range of biological processes. Serpins are researched limited in Taenia solium, although some are considered to participate in host immune responses. Tsserpins were identified as typical serpins due to the primary structure of characteristic features: the serpin motif, serpin signature and reaction centre loop (RCL). RCLs of four serpin genes (TsB6, Ts4848, Ts12383 and Ts570) contained the conserved sequences of inhibitory serpins, which may involve in immune regulation. TsEP45 differed greatly from the patterns of representative serpins, suggesting that TsEP45 may be non-inhibitory. The bioinformatic analyses were supposed that Tsserpins might be a potential antigen for diagnosis. The five recombinant Tsserpin proteins were expressed and identified reacting with Cysticercus cellulosae-positive serum samples. The indirect enzyme-linked immunosorbent assay (iELISAs) based on Tsserpins were developed and validated, one of the five Tsserpins, TsEP45, showed excellent diagnostic results with 93·33% sensitivity and 94·12% specificity, respectively. This performance was in perfect accordance with the results of the bioinformatic analysis. This study provided a comprehensive demonstration of sequences and structural-based analysis of Tsserpins. The iELISAs based on five Tsserpins were developed and compared. TsEP45 was the potential species-specific antigen for developing iELISA to detect porcine cysticercosis.

scholarly journals Hydrophobic fraction of Taenia saginata metacestodes, rather than hydrophilic fraction, contains immunodominant markers for diagnosing human neurocysticercosis

2010 ◽  
Vol 43 (3) ◽  
pp. 254-259 ◽  
Author(s):  
Flávia de Assunção Gonçalves ◽  
Gleyce Alves Machado ◽  
Heliana Batista Oliveira ◽  
Maria Teresa Nunes Pacheco Rezende ◽  
José Roberto Mineo ◽  
...  
Keyword(s):  
Taenia Solium ◽  
Taenia Saginata ◽  
Serum Samples ◽  
Igg Antibody ◽  
Saline Extract ◽  
Normal Individuals ◽  
Homologous Antigen ◽  
Immunoblotting Assay ◽  
Inspection Service ◽  
Hydrophobic Fraction

INTRODUCTION: Considering that alternative antigens for diagnosing neurocysticercosis continue to be a challenge because of the increasing difficulty in obtaining parasites from naturally infected pigs for preparation of Taenia solium homologous antigen, the aim of the present study was to evaluate the detergent (D) and aqueous (A) fractions from saline extract of Taenia saginata metacestodes for diagnosing neurocysticercosis. METHODS: Taenia saginata was obtained from naturally infected bovines in the Triângulo Mineiro region, State of Minas Gerais, Brazil. The carcasses came from cold storage units and had been slaughtered in accordance with the inspection technique recommended by the Federal Inspection Service. The D and A fractions were obtained by using Triton X-114 (TX-114). Serum samples were obtained from 40 patients with a diagnosis of neurocysticercosis, 45 with other parasitic diseases and 30 from apparently normal individuals. IgG antibody levels were evaluated using the ELISA and immunoblotting assays. RESULTS: The ELISA sensitivity and specificity were 95% and 73.3%, when using saline extract; 95% and 82.6% for the D fraction; and 65% and 61.3% for the A fraction, respectively. The immunoblotting assay confirmed the ELISA results, such that the D fraction was more efficient than the other extracts, and the 70-68kDa component was immunodominant among neurocysticercosis patients. CONCLUSIONS: These results demonstrated that the D fraction from Taenia saginata metacestodes obtained using TX-114 can be used as a heterologous antigenic fraction in the immunoblotting assay for serologically diagnosing human neurocysticercosis, given its ability to select immunodominant antigens.

scholarly journals Enzyme-Linked Immunosorbent Assay Using Recombinant SAG1 Antigen To Detect Toxoplasma gondii-Specific Immunoglobulin G Antibodies in Human Sera and Saliva

2013 ◽  
Vol 20 (4) ◽  
pp. 468-473 ◽  
Author(s):  
Nouha Chahed Bel-Ochi ◽  
Aïda Bouratbine ◽  
Mohamed Mousli
Keyword(s):  
Toxoplasma Gondii ◽  
Sensitivity And Specificity ◽  
Specific Antigen ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Native Form ◽  
Content Type ◽  
Percent Agreement ◽  
Human Sera ◽  
Commercial Kits

ABSTRACTSerologic detection ofToxoplasma gondiiIgG antibodies is widely accepted as a means to determine immune status and susceptibility toToxoplasmainfection during pregnancy. However, current commercial kits present some drawbacks, such as a requirement for whole-parasite antigen preparation or interassay variability. To address these problems, the purpose of this study was to produce a whole sequence of the recombinantT. gondiiSAG1 antigen (rSAG1) to assess its diagnostic performance inToxoplasmaIgG screening and to explore a saliva-based method as a noninvasive alternative to serum-based testing. rSAG1 was expressed in recombinant bacteria as inclusion bodies, purified through one-step affinity chromatography, and refolded in native form by dialysis. A large amount was obtained, and the specific antigen immunoreactivity was confirmed by immunoblotting. Two rSAG1-based enzyme-linked immunosorbent assays (ELISAs) applied to paired serum and saliva samples were designed. The rSAG1-based ELISA evaluation consisted of testing intrinsic sensitivity and specificity of 49 serum samples from patients immune to toxoplasmosis and 42 serum samples from nonimmune controls identified by routinely used kits. To assess agreement between serum-based and saliva-based tests, the positive percent agreement (PPA) and negative percent agreement (NPA) between the 2 tests were estimated. The rSAG1 serum-based ELISA detected specific IgG with 100% sensitivity and specificity. The PPA and NPA between the serum-based and saliva-based tests varied according to the selected optical density threshold in saliva. Thus, for a selected cutoff of 0.14, the PPA was 100% and the NPA was 88.1%, whereas for a selected cutoff of 0.29, the PPA was 67.3% and the NPA was 100%.

scholarly journals Use of Taenia crassiceps Cysticercus Antigen Preparations for Detection of Antibodies in Cerebrospinal Fluid Samples from Patients with Neurocysticercosis (Taenia solium)

2002 ◽  
Vol 9 (1) ◽  
pp. 190-193 ◽  
Author(s):  
Alessandra Xavier Pardini ◽  
Regina Helena Peralta ◽  
Adelaide José Vaz ◽  
Luis dos Ramos Machado ◽  
José Mauro Peralta
Keyword(s):  
Cerebrospinal Fluid ◽  
Affinity Chromatography ◽  
Molecular Mass ◽  
Sensitivity And Specificity ◽  
Concanavalin A ◽  
Taenia Solium ◽  
Enzyme Linked Immunosorbent Assay ◽  
Good Reproducibility ◽  
Taenia Crassiceps ◽  
Glycoprotein Antigen

ABSTRACT Antigen extracts obtained from the vesicular fluid of Taenia crassiceps cysticerci and from fractions purified by affinity chromatography with the lectin concanavalin A and the glycoprotein antigen separated by electrophoresis were used for the detection of Taenia solium anticysticercus antibodies. The sensitivity and specificity obtained for all antigens were 100% in enzyme-linked immunosorbent assay with good reproducibility. Using immunoblotting of the three antigens, low-molecular-mass peptides (18 and 14 kDa) were characterized only in cerebrospinal fluid samples from patients with neurocysticercosis. The results confirm that antigen fractions purified from T. crassiceps cisticerci are important sources of specific peptides and proved to be efficient in detecting anti-T. solium antibodies.

scholarly journals Evaluation of two Taenia solium cysticercal antigenic preparations (vesicular fluid and a glycoprotein fraction with affinity for lentil lectin) for the immunodiagnosis of neurocysticercosis by enzyme-linked immunosorbent assay (ELISA)

2011 ◽  
Vol 69 (3) ◽  
pp. 470-474 ◽  
Author(s):  
Lisandra Akemi Suzuki ◽  
Cláudio Lúcio Rossi
Keyword(s):  
Sensitivity And Specificity ◽  
Immunosorbent Assay ◽  
Taenia Solium ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Lectin Affinity Chromatography ◽  
Serum Samples ◽  
Lentil Lectin ◽  
Significant Difference ◽  
Parasite Extract

OBJECTIVE: To evaluate the performance of two antigenic preparations (vesicular fluid - VF and a glycoprotein fraction, LLa-Gp fraction, purified from a whole parasite extract by lentil lectin affinity chromatography) from Taenia solium cysticerci for the immunodiagnosis of neurocysticercosis. METHOD: Fifty-six cerebrospinal fluid (CSF) samples (22 from patients with neurocysticercosis and 34 from patients with other neurological disorders) and 57 serum samples (22 from patients with neurocysticercosis, 18 from patients with other infections and 17 from presumably healthy persons) were assayed for anticysticercal IgG antibodies with an enzyme-linked immunosorbent assay (ELISA). RESULTS: The VF ELISA showed 100% sensitivity and specificity in CSF and serum samples, whereas the sensitivity and specificity of the LLa-Gp ELISA were, respectively, 90.9% and 97.1%, with the CSF samples and 95.5% and 100% with serum samples. There was no significant difference in the sensitivity and specificity of the two antigenic preparations used to screen CSF and serum samples. CONCLUSION: Considering the complexity and high cost of obtaining the LLa-Gp fraction, VF could be more suitable for screening specific antibodies by ELISA in CSF and serum samples from patients with neurocysticercosis.

scholarly journals Immunodiagnosis of human neurocysticercosis by using semi-purified scolex antigens from Taenia solium cysticerci

2007 ◽  
Vol 40 (2) ◽  
pp. 163-169 ◽  
Author(s):  
Francesco Iudici Neto ◽  
Geraldo Pianetti-Filho ◽  
Ricardo Nascimento Araújo ◽  
Evaldo Nascimento
Keyword(s):  
Sensitivity And Specificity ◽  
Excellent Agreement ◽  
Taenia Solium ◽  
Polyacrylamide Gel ◽  
Parasitic Diseases ◽  
Serum Samples ◽  
Serological Screening ◽  
Crude Antigen ◽  
Normal Individuals ◽  
Confirmatory Tests

Crude antigen and semi-purified proteins from scolices of Taenia solium cysticerci were evaluated for the immunodiagnosis of human neurocysticercosis neurocysticercosis. Semi-purified proteins obtained by electrophoresis on polyacrylamide gel and by electroelution were tested by means of the immunoenzymatic reaction against sera from normal individuals and from patients with neurocysticercosis or other parasitic diseases. The 100kDa protein provided 100% sensitivity and specificity in the immunodiagnosis. When 95 or 26kDa proteins were used, 95 and 100% sensitivity and specificity were obtained, respectively. The assays involving crude antigen and sera from normal individuals or from patients with neurocysticercosis, diluted to 1:256, gave excellent agreement with those in which 100, 95 or 26kDa proteins were tested against the same serum samples diluted to 1:64. (Kappa: 0.95 to 1.00). Crude scolex antigen may be useful for serological screening, while 100, 95 or 26kDa protein can be used in confirmatory tests on neurocysticercosis-positive cases.

scholarly journals Evaluation of an enzyme immunoassay for clinical diagnosis of neurocysticercosis in symptomatic patients

2010 ◽  
Vol 43 (6) ◽  
pp. 647-650 ◽  
Author(s):  
Reynaldo Mendes de Carvalho Junior ◽  
Dorcas Lamounier Costa ◽  
Savyo Carvalho Soares ◽  
Carlos Henrique Nery Costa
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Sensitivity And Specificity ◽  
Cerebral Spinal Fluid ◽  
Taenia Solium ◽  
Enzyme Linked Immunosorbent Assay ◽  
Parasitic Disease ◽  
Multivariate Logistic Regression ◽  
Human Central Nervous System ◽  
Elisa Kit

INTRODUCTION: Neurocysticercosis is an infection of the human central nervous system caused by the metacestode larvae of Taenia solium. Neurocysticercosis is the most common parasitic disease in developing countries. Epilepsy is the most common clinical manifestation. Difficulties in confirming the diagnosis motivated the evaluation of the enzyme-linked immunosorbent assay on cerebral spinal fluid (CSF). METHODS: Twenty-two patients with NCC and 44 control patients were studied. CSF was analyzed using a commercial ELISA kit developed for NCC. Sensitivity and specificity were measured and a multivariate logistic regression was performed. RESULTS: Sensitivity and specificity of ELISA were 31.8% and 100%, respectively, with accuracy of 77.3%. Only the size of the lesions proved to be important for performance of the test. CONCLUSIONS: The results showed that ELISA contributes to the diagnosis of neurocysticercosis if the result is negative or if the patient has a lesion of 2 cm or more.

scholarly journals Quantitative Approach for the Serodiagnosis of Canine Lyme Disease by the Immunoblot Procedure

2000 ◽  
Vol 38 (7) ◽  
pp. 2628-2632 ◽  
Author(s):  
Marta A. Guerra ◽  
Edward D. Walker ◽  
Uriel Kitron
Keyword(s):  
Logistic Regression ◽  
Lyme Disease ◽  
Natural Infection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Immunoblot Assay ◽  
Serological Status ◽  
Low Probability ◽  
Positive Results ◽  
Logistic Regression Equation

Serum samples obtained from healthy, asymptomatic dogs in areas of Wisconsin and northern Illinois where Lyme disease is endemic or nonendemic were assayed for antibodies to Borrelia burgdorferi by enzyme-linked immunosorbent assay (ELISA), and positive results were confirmed by immunoblot assay. We found that 56.9% (562 of 1,077) of the samples were positive by ELISA and 82.0% (461 of 562) were positive by immunoblotting. A logistic regression model was developed to distinguish between nonvaccinated dogs naturally infected with B. burgdorferi from areas where the disease is endemic and dogs from areas where the disease is nonendemic that were vaccinated against Lyme disease. Of the 18 protein bands analyzed, 8 were found to be significantly different (P < 0.05) between the two groups. p93, p34, p31, and p28 occurred with increased frequency in vaccinated dogs, while p58, p37, p35, and p30 occurred more frequently in naturally infected dogs. The logistic regression equation obtained was used to determine the probability of natural infection among vaccinated dogs residing in areas where the disease is endemic. Of 125 samples, 87.2% had a very low probability of natural infection and only 2.4% were highly likely to be infected. Logistic regression is a useful method for distinguishing between vaccinated and naturally infected dogs and predicting the serological status of vaccinated dogs from areas where Lyme disease is endemic.

scholarly journals Diagnosis of Visceral Leishmaniasis by Enzyme-Linked Immunosorbent Assay Using Urine Samples

2002 ◽  
Vol 9 (4) ◽  
pp. 789-794 ◽  
Author(s):  
Mohammad Zahidul Islam ◽  
Makoto Itoh ◽  
S. M. Shamsuzzaman ◽  
Rusella Mirza ◽  
Farzana Matin ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Sensitivity And Specificity ◽  
Immunosorbent Assay ◽  
Leishmania Donovani ◽  
Laboratory Diagnosis ◽  
Urine Samples ◽  
Enzyme Linked Immunosorbent Assay ◽  
Healthy Controls ◽  
Serum Samples ◽  
Crude Antigen

ABSTRACT A diagnostic method has been developed to detect anti-Leishmania donovani immunoglobulin G (IgG) in urine by enzyme-linked immunosorbent assay (ELISA). In measuring anti-L. donovani IgG, IgA, and IgM in urine, the method performed best in the detection of IgG. The sensitivity and specificity of the assay were determined with panels of urine samples from 62 visceral leishmaniasis (VL) patients, 59 healthy controls from areas of endemicity, 53 healthy controls from areas of nonendemicity, 59 malaria patients, 13 tuberculosis patients, 23 cutaneous leishmaniasis patients, and 7 patients with other diseases. Using L. donovani promastigote crude antigen, the test had 93.5% sensitivity (58 positives of 62 VL patient samples) and 89.3% specificity (191 negatives of 214 non-VL patient samples). The ELISA with acetone-treated L. donovani promastigote antigen raised the sensitivity and specificity to 95.0 and 95.3%, respectively. Western blot analysis revealed that most of the samples that cross-reacted with crude antigen in ELISA did not recognize any antigenic component of L. donovani crude antigen. We also checked 40 serum samples from the same group of VL patients for anti-L. donovani IgG and got 90.0% sensitivity with both crude and acetone-treated antigens. As collection of urine is much easier than collection of serum, the detection of anti-L. donovani IgG in urine with acetone-treated antigen will be useful in epidemiological studies. It could be an adjunct of laboratory diagnosis.

scholarly journals Evaluation of a Blocking ELISA Using a Urease Conjugate for the Detection of Antibodies to Pseudorabies Virus

2000 ◽  
Vol 12 (3) ◽  
pp. 266-268 ◽  
Author(s):  
Maria Gabriela Echeverría ◽  
Edgardo Omar Nosetto ◽  
Maria Elisa Etcheverrigaray
Keyword(s):  
Sensitivity And Specificity ◽  
Immunosorbent Assay ◽  
Pseudorabies Virus ◽  
Visual Assessment ◽  
Field Conditions ◽  
Virus Neutralization ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Blocking Elisa ◽  
Elisa Format

A blocking enzyme-linked immunosorbent assay (ELISA) using a urease conjugate (U-B-ELISA) was evaluated for screening sera for antibodies to pseudorabies virus under field conditions. A total of 764 serum samples were analyzed by U-B-ELISA. Of these, 264 were evaluated by both virus neutralization and U-B-ELISA, and the results were compared. U-B-ELISA showed 98.5% and 98.9% sensitivity and specificity, respectively. This test combines the sensitivity and specificity of the blocking ELISA format while allowing visual assessment of results.

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