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Characterization, cloning, and expression of two diagnostic antigens for Taenia solium tapeworm infection

Authors:
Min Levine at Centers for Disease Control and Prevention
Min Levine
J. C. Calderón S
J. C. Calderón S
J. C. Calderón S
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Patricia P Wilkins
Patricia P Wilkins
Patricia P Wilkins
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William S Lane at Harvard University
William S Lane
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Abstract

Adult and larval stages of Taenia solium cause 2 diseases in humans, i.e., taeniasis and cysticercosis, respectively. Diagnosis and treatment of taeniasis are the ultimate means to eliminate cysticercosis. A serological taeniasis diagnostic test has been developed for laboratory use. However, recombinant forms of the taeniasis diagnostic proteins are required to overcome the limited supply of native proteins and allow the development of a low-cost and field-applicable test with high sensitivity and specificity. Using 2-dimensional electrophoresis of T. solium excretory and secretory (TSES) products from hamster adult tape-worm in vitro cultures, we have identified 5 T. solium-specific protein spots, with molecular weights of 33 kDa (protein isoelectrofocusing point [pI]: 5.6, 5.3, 5.1) and 38 kDa (pI: 4.6, 4.5). Protein sequencing and molecular cloning of these proteins showed that although endowed with different pls, the proteins with the same molecular weights shared the same protein backbone, named TSES33 and TSES38. Their full-length complementary DNAs encode proteins with 267 and 278 amino acids, respectively. TSES33 and TSES38 were expressed in a baculovirus system. Both recombinant proteins were recognized by a panel of taeniasis, but not cysticercosis patient serum samples, indicating that they can potentially replace the native proteins in the development of a more efficacious taeniasis diagnostic test.
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Supplementary resources (2)

Taenia solium diagnostic protein TSES38 mRNA, complete cds
Nucleotide Sequence
July 2002
P.P. Wilkins · M. Lovegrove · M. Levine · V.C.W. Tsang
Taenia solium TSES33 mRNA, complete cds
Nucleotide Sequence
November 2002
M.Z. Levine · V.C.W. Tsang
... Over the past few years, we characterized the clinical correlation of each antigen family and confirmed the need to include all of these in the diagnostic approach in order to improve the overall interpretation of antibody seropositivity (16,17). Synthetic and recombinant proteins have also become increasingly available, with new production techniques and suppliers making mass production of these a viable option. ...
... The 8 kDa family and its synthetic forms, made from hydrophilic proteins lacking transmembrane regions and anchoring sites, suggested that these are extracellularly secreted proteins. The chemically synthesized recombinant forms, sTs18 var1, sTs14, sTsRS1, and sTsRS2var1, demonstrated different performances close to 70% of sensitivity and 97% of sensitivity, with some cross-reaction with the T24-42 family (16,28,34). ...
Multiantigen print immunoassay (MAPIA) for the diagnosis of neurocysticercosis: a single-center diagnostic optimization and accuracy study in Lima, Peru
Article
Full-text available
Neurocysticercosis (NCC) is the most common helminthic infection of the human central nervous system. The antibody detection assay of choice is the enzyme-linked immunoelectrotransfer blot assay using lentil-lectin purified parasite antigens (LLGP-EITB, Western blot), an immunoassay with exceptional performance in clinical samples. However, its use is mainly restricted to a few research laboratories because the assay is labor-intensive and requires sophisticated equipment, expertise, and large amounts of parasite material for preparation of reagents. We report a new immunoprint assay (MAPIA) that overcomes most of these barriers. We initially compared the performance of five different antigen combinations in a subset of defined samples in the MAPIA format. After selecting the best-performing assay format (a combination of rGP50 + rT24H + sTs14 antigens), 148 archived serum samples were tested, including 40 from individuals with parenchymal NCC, 40 with subarachnoid NCC, and 68 healthy controls with no evidence of neurologic disease. MAPIA using three antigens (rGP50 + rT24H + sTs14) was highly sensitive and specific for detecting antibodies in NCC. It detected 39 out of 40 (97.5%) parenchymal NCC cases and 40/40 (100%) subarachnoid cases and was negative in 67 out of 68 (98.53%) negative samples. MAPIA using three recombinant and synthetic antigens is a simple and economical tool with a performance equivalent to the LLGP-EITB assay for the detection of specific antibodies to NCC. The MAPIA overcomes existing barriers to adoption of the EITG LLGP and is a candidate for worldwide use.
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... Despite this, none of the developed tests have been evaluated for practical use in either health facilities or communities. Recently, a new, single-cassette, bi-strip, prototype point of care test (TS POC) based on the recombinant antigens rES33 [19] and rT24H [11], for simultaneous detection of anti-taeniosis (TS POC T) and anti-cysticercosis (TS POC CC) antibodies, respectively, has been developed by the Centers for Disease Control and Prevention (CDC, Atlanta, GA, USA) collaborating with the Technical University of Munich (TUM, Munich, Germany). The objective of this study was to evaluate the TS POC CC sensitivity and specificity for diagnosis of HCC in a community setting. ...
... The prototype TS POC is a standard lateral flow assay with two test strips in one cassette developed for diagnosis of cysticercosis (TS POC CC) and taeniosis (TS POC T) ( Figure 1) [22]. It is based on two previously characterized and used recombinant proteins, rT24H [23] and rES33 [11,19]. Each test strip has a separate sample port, test and control line and an absorbent pad. ...
Evaluation of an Antibody Detecting Point of Care Test for Diagnosis of Taenia solium Cysticercosis in a Zambian Rural Community: A Prospective Diagnostic Accuracy Study
Article
Full-text available
  • Nov 2021
The lack of cheap, easy-to-use, rapid diagnostic tests has led to the development of several rapid diagnostic tests for cysticercosis. The new prototype two-strip, Taenia solium point of care test (TS POC) detects antibodies against taeniosis (TS POC T) and cysticercosis (TS POC CC). This study evaluated the diagnostic performance of the TS POC CC in the Sinda district in eastern Zambia. A sample of 1254 participants was recruited and tested with the TS POC. Out of the 1249 participants with a valid TS POC result, 177 (14%) tested positive while 1072 (86%) tested negative. All individuals with a positive TS POC and a subset of negative TS POC participants were selected for serum sampling, and were subjected to the recombinant glycoprotein T24H enzyme-linked immunoelectrotransfer blot (rT24H EITB) and the serum B60/158 (serum Ag) enzyme-linked immunosorbent assay (Ag ELISA). Performance characteristics were estimated using a Bayesian approach with probabilistic constraints. Based on 255 complete cases, the estimated sensitivity and specificity of the TS POC CC test were 35% (95% CI: 14–63%) and 87% (95% CI: 83–90%), respectively. The diagnostic performance needs to be improved, possibly by titrating antigen and other reagents’ concentration in the strip to produce a performance similar to existing cysticercosis tests such as the rT24H EITB.
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... An antibody-detecting prototype test (TS POC) has been developed by a team of researchers from the Centers for Disease Control and Prevention (CDC), Atlanta, USA, in collaboration with the Department of Neurology, Klinikum rechts der Isar, Technical University of Munich (TUM), Germany. The TS POC test combines two well-validated and extensively used recombinant proteins in one multi-strip test kit: rT24H for the detection of CC antibodies (TS POC CC), and rES33 for the detection of T antibodies (TS POC T) [9,10]. Recombinant antigens were chosen for the present TS POC prototype to facilitate a future standardized low-cost production of this test for resource-poor settings. ...
... The TS POC is an antibody-detecting prototype test developed by a team of researchers from the CDC in collaboration with TUM and is based on two previously characterized and extensively used recombinant proteins, rES33 and rT24H [9,10]. This test is an inhouse produced standard lateral flow assay (LFA), which consists of a double-strip cassette that holds two separate strips: one strip for the detection of taeniosis antibodies (by using the rES33 protein) and one for cysticercosis antibodies (by using the rT24H protein). ...
Trial Design for a Diagnostic Accuracy Study of a Point-of-Care Test for the Detection of Taenia solium Taeniosis and (Neuro)Cysticercosis in Community Settings of Highly Endemic, Resource-Poor Areas in Zambia: Challenges and Rationale
Article
Full-text available
  • Jun 2021
Field-applicable, high-quality, and low-cost diagnostic tools are urgently needed for Taenia solium. The aim of this paper is to describe the design, challenges, and rationale for the design of a diagnostic accuracy study in low-resource community settings in Zambia. The trial was designed as a prospective study with a two-stage design to evaluate a new point-of-care test (TS POC) for the detection of taeniosis and (neuro)cysticercosis. Participants within randomly selected households were tested with the TS POC test (index test). Participants who tested TS POC positive for taeniosis and/or cysticercosis and a subset of the negatives were requested to give blood and stool samples for reference testing, and to undergo clinical examination and a cerebral CT scan. The difficulties of conducting a clinical trial in settings with limited research and neuroimaging infrastructure as well as peculiarities specifically related to the disease (low prevalence of taeniosis and the lack of a gold standard) were taken into consideration for the design of this study. The two-stage design increased the efficiency of the study by reducing the number of samples, clinical examinations, and CT scans. Simplified flows and sampling processes were preferred over complex follow-up and randomization systems, aiming to reduce bias and increase the generalizability of the study.
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... When employed to test sera with confirmed infection status, including sera from beef tapeworm carriers and Echinococcus infected persons, the assay obtained a Se/Sp of 95%/100%, respectively (Wilkins et al. 1999). However, use of local antigens limited the test's applicability outside the laboratory, and antigens have recently been generated in a baculo-virus system for application in different tests (Levine et al. 2004). rES33 and rES38 proteins are now being employed in an enzymelinked immunoelectrotransfer blot (EITB) format in a current eradication programme against cysticercosis in Peru, with both demonstrating great sensitivity of 97.0% and 98.0% (rES33) and specificity of 100% and 91.0% ...
Global Review of Human Taeniasis
Chapter
Full-text available
  • Mar 2023
Human taeniasis is a zoonotic cestodal infection caused by worms of Taeniidae family. Although the disease has widespread distribution, communities in the developing nations bear the most of its burden. This chapter covers the worldwide distribution, diagnostic tests adopted, treatment options, and control strategies of human taeniasis
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... The TS POC is an antibody detecting prototype test based on two previously characterized and extensively used recombinant proteins, rES33 and rT24H [20,21]. It is an in-house produced standard lateral flow assay (LFA) which consists of a double-strip cassette ( Figure 3) that holds two separate strips: one strip for the detection of taeniosis antibodies (by using the rES33 protein) and one for the detection of cysticercosis antibodies (by using the rT24H protein). ...
Challenges Encountered When Evaluating an Antibody-Detecting Point-of-Care Test for Taeniosis in an Endemic Community in Zambia: A Prospective Diagnostic Accuracy Study
Article
Full-text available
  • Nov 2021
Taenia solium taeniosis diagnosis is challenging because current tests perform sub-optimally and/or are expensive, require sophisticated equipment, infrastructure and trained manpower, and therefore are not community deployable. A recently-developed, multi-strip, T. solium point-of-care test (TS POC) for simultaneous detection of tapeworm (TS POC T) and cysticercus (TS POC CC) human antibodies was evaluated for diagnostic accuracy on consecutively recruited community participants in Sinda district, Zambia. All participants were tested using the TS POC test. All test-positives and 20% of the test-negative participants were invited to give a blood and stool sample for reference testing. Three different reference tests were used for taeniosis diagnosis: recombinant rES33 enzyme-linked immunoelectrotransfer blot (rES33 EITB), copro PCR and copro Ag ELISA. Bayesian analysis with probabilistic constraints was used to estimate sensitivity and specificity. In total, 1254 participants were tested with the TS POC test, of whom 13 tested positive using the TS POC T. Based on 161 participants with complete data, the estimated sensitivity and specificity for the TS POC T test were 38% (95% CI: 5–93%) and 99% (95% CI: 98–100%), respectively. The challenge of highly variable inter-assay performance is highlighted. We recommend either increasing the sensitivity or redesigning the test.
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... To summarize, the TS POC test is an antibody-detecting prototype developed by a team of researchers from the USA and Germany. The TS POC test consists of a double-strip cassette that holds one strip for the detection of antibodies against the adult stage (using the recombinant T antigen rES33), and one to detect antibodies against the larval stage of the parasite (using the recombinant CC antigen rT24H) [12,13]. Each strip has one test line, one control line, and a separate port for the sample application, enabling the simultaneous detection of T and CC antibodies. ...
Trial Design of a Prospective Multicenter Diagnostic Accuracy Study of a Point-of-Care Test for the Detection of Taenia solium Taeniosis and Neurocysticercosis in Hospital-Based Settings in Tanzania
Article
Full-text available
  • Aug 2021
Taenia solium diagnosis is challenging as trained personnel, good diagnostic tools, and infrastructure is lacking in resource-poor areas. This paper aims to describe the study trial design adopted to evaluate a newly developed rapid point-of-care test that simultaneously detects taeniosis and neurocysticercosis (TS POC) in three district hospitals in Tanzania. The two-stage design included three types of patients: patients with specific neurological signs and symptoms (group 1); patients with complaints compatible with intestinal worm infections (group 2); patients with other symptom(s) (group 3). For group 1, all patients were tested using the TS POC test (stage 1), after which all positive, and a subset of negative, patients were selected for laboratory reference tests, clinical examination, and a brain computed tomography (CT) scan (stage 2). For groups 2 and 3, a similar design was adopted, but clinical examination and a brain CT scan (stage 2) were only performed in patients who were TS POC test-positive for cysticercosis. Due to the lack of a gold standard, a Bayesian approach was used to determine test accuracy for taeniosis and cysticercosis. For neurocysticercosis, a composite case definition was used as the reference standard. If successful, this study will help the future developments (commercialization and implementation) of the rapid test and improve patient management and disease prevention.
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... The Taenia solium point of care test (TS POC) The TS POC (Fig. 1B below) is an in-house prototype rapid diagnostic test for the simultaneous detection of taeniosis (TST) and cysticercosis (TSCC) antibodies in a lateral-flow format based on two recombinant proteins, rES33 and rT24H, respectively [12,13]. The test kits (each comprising of one TS POC cassette and one desiccant sealed together in an aluminum pouch) were supplied together with chase buffer in dispensing dropper bottles (Fig. 1A) and additional calibrated squeezable micropipettes (Microsafe Capillary Tubes 20ul, SafeTec, PA, USA) (Fig. 1C) by the Klinikum Rechts der Isar, Technical University Munich, Germany, and the Division of Parasitic Diseases and Malaria, Center for Global Health, Center for Disease Control and Prevention (CDC), Atlanta, Georgia, USA, and shipped from the latter to the study sites. ...
Operational characteristics of an antibody detecting point of care test for Taenia solium infections in a community and hospital setting
Article
Full-text available
  • Jun 2021
  • BMC INFECT DIS
Background Diagnostic test evaluation includes measures of performance and assessment of operational characteristics. The latter focuses on end-user understanding of instructions to perform the test, ease of use, test turnaround time and ease of result interpretation. This study aimed to assess user comprehension of training for and ease of use of a Taenia solium point of care test (TS POC) evaluated in a community and hospital setting in Zambia and Tanzania, respectively. Methods The TS POC is a three-step in-house-produced rapid diagnostic test (RDT) for the simultaneous detection of taeniosis (TST) and cysticercosis (TSCC) antibodies. Data collected by administering questionnaires to 29 end-users and from the main evaluation database was analyzed quantitatively. Results End-users (28/29, 97%) perceived that the training they received for performing the test was sufficient. They performed 4080 tests, of which 80 were invalid. The community-based study and TST tests had higher invalid rates. The overall result interpretation was within the acceptable range of RDTs with an overall disagreement between readers of 3.3%. The Kappa coefficient of agreement was 85 and 82% for TSCC and TST, respectively. There was more disagreement among readers in the community-based study. Conclusion End-users rated the TS POC kit moderate in terms of ease of use citing long test turnaround time and difficulties in using the blood transfer device. Overall, the operational performance of the TS POC kit and end-users was within the established acceptable performance range.
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Evaluation of a rapid lateral flow assay for the detection of taeniosis and cysticercosis at district hospital level in Tanzania: A prospective multicentre diagnostic accuracy study
Preprint
Full-text available
  • Jun 2024
The TS POC test, Taenia solium point-of-care test, is a two-strip lateral flow assay using the recombinant antigen rES33 on the TS POC T test strip, and rT24H on the TS POC CC test strip, to detect antibodies against T. solium taeniosis and cysticercosis, respectively. The objective of this study was to assess the diagnostic performance of the TS POC test for the detection of T. solium taeniosis and cysticercosis in individuals attending district hospitals in Tanzania. In this prospective two-phase diagnostic accuracy study, we recruited participants aged 10 and above, excluding pregnant women and those with acute severe illness. Participants were consecutively recruited in three cohorts according to their signs/symptoms: compatible with neurocysticercosis (cohort 1), intestinal worm infections (cohort 2), and other symptoms (cohort 3). Lacking a gold standard test for both infections, evaluating the diagnostic accuracy measures was done using the results of different coprological and serological tests in a Bayesian Latent Class Model approach. The TS POC test was conducted on 601 participants in cohort 1, 1661 participants in cohort 2, and 662 participants in cohort 3. Most individuals tested negative on both TS POC test strips, with proportions of 83% (n = 496), 97% (n = 1613) and 97% (n = 641) in cohorts 1, 2 and 3, respectively. Sensitivity values for the TS POC T test strip were 50.2% [4.9 - 96.4], 40.8% [2.2 - 95.2], and 40.4% [2.3 – 95.0], while specificity values were 98.6% [97.1 - 99.6], 99.3% [98.7 - 99.7] and 99.4% [98.5 - 99.9], respectively. For the TS POC CC test strip, the sensitivity was 77.5% [37.8 - 99.2], 24.9% [95% CI 6.4 - 52.7] and 44.2% [6.6 - 91.5], and the specificity 92.3% [86.5 - 98.8], 99.1% [97.8 - 100], and 98.1% [96.1 - 99.7] across the respective cohorts. Although the TS POC test has a suboptimal sensitivity, it demonstrates a high specificity, which may have clinical utility to guide treatment and diagnostic decisions, or in epidemiological studies. An important strength of this study lies in its assessment of the TS POC test under real-world conditions, revealing divergent estimates across distinct cohorts. The study underscores the suboptimal performance of existing tests under field conditions, emphasizing the need for the development and validation of better diagnostic tests.
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Taeniasis and Cysticercosis
Chapter
  • Aug 2022
Taeniasis and cysticercosis are zoonotic diseases caused by Taenia saginata and Taenia solium. Tapeworms can infect the human intestine and have a wide geographic distribution. Taenia asiatica, another tapeworm species, was described in Southeast Asia. Larval stages of these cestodes (metacestodes or cysticerci) cause cysticercosis; T. saginata causes bovine cysticercosis, T. asiatica larvae develop in pig viscera, and T. solium may lead to cysticercosis in pig and human. Invasion of the central nervous system (CNS) by parasite larvae may cause neurocysticercosis (NCC), one of the most prevalent parasitic infections of the human CNS. Taeniasis and cysticercosis continue to cause health problems and livestock industry losses in endemic areas as well as in non-endemic regions associated with travel and migrations. There are few symptoms associated with taeniasis. On the other hand, neurocysticercosis is pleomorphic and may be life-threatening, depending on the location, number, stage of cysticerci, and host immune response. Diagnosis of taeniasis is generally done by microscopic examinations of stool; detection of cysticercosis is generally performed by neuroimaging and immunoassays. Both conventional coprological techniques and immunological assays show limitations, and new more specific and sensitive diagnostic tools have been developed such as specific monoclonal antibodies, recombinant antigens, synthetic peptides, and PCR. Considering the clinical impact, veterinary problems, and economic losses derived from taeniasis/cysticercosis, control programs have been implemented. Moreover, several vaccine candidates have been characterized to complement control measures.
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Epidemiology of taeniasis and cysticercosis in a Peruvian village. The Cysticercosis Working Group in Peru
Article
Full-text available
  • May 1992
  • AM J EPIDEMIOL
To determine the prevalence of cysticercosis in a rural area where the disease is endemic, the authors studied the seroepidemiology of human and porcine cysticercosis in a Peruvian jungle community (Maceda, Peru) in 1988 using an enzyme-linked immunoelectrotransfer blot (EITB) assay. Of the 371 sampled inhabitants, 30 (8%) were seropositive, most of whom were asymptomatic. After niclosamide therapy, four Taenia species worms were identified in the seropositive group, compared with one in the control group (p = 0.06). Pigs were frequently infected: 44 of 133 (33%) were found positive for Taenia by tongue examination and 57 of 133 (43%) were positive by EITB. In 69% of the sampled households that had pigs, there was at least one seropositive pig. The number of pigs diagnosed positive by the tongue examination was significantly greater in households that had latrines than in those that did not. Cysticercosis is a common but usually asymptomatic infection that affects both humans and pigs in the high jungle areas of Peru.
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Immunodiagnosis of taeniasis by coproantigen detection
Article
Full-text available
  • Jan 1991
Immunodiagnostic tests for Taenia-specific faecal antigen based on polyclonal rabbit antisera against Taenia saginata or Taenia solium proglottid extracts in capture-type ELISA assays have been developed. Taenia-specific antigen was detected in detergent-solubilized faecal extracts from T. solium- and T. saginata-infected hosts. Coproantigen from T. solium-infected hamsters did not cross-react with faeces from rodents infected with Hymenolepis diminuta, H. citelli, H. microstoma, Necator americanus, Strongyloides ratti or Nematospiroides dubius and faeces from uninfected animals. When the T. saginata-capture ELISA was tested with faecal samples positive for T. solium antigen, no cross-reactions were obtained. However, faecal samples from humans infected with T. solium or T. saginata, including some with extremely low egg counts, were cross-reactive by either test. Nevertheless, considerably higher O.D. values were obtained with stool samples from Taenia patients compared to Hymenolepis nana-infected or uninfected individuals. Two individuals, infected with Taenia sp. and positive for coproantigens by ELISA, became antigen-negative 6 days after treatment with Niclosamide. The possibility of developing species-specific immunodiagnostic tests for human taeniasis through coproantigen detection is discussed.
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Taenia solium cysticercosis: An under-recognized but serious public health problem
Article
  • Mar 1995
  • Parasitol Today
The true impact and scope of the disease cysticercosis have been obscured by the lack of sensitive and specific diagnostic tools for the collection of reliable epidemiological data. Diagnosis has hitherto been dependent on clinical observations, radiologic imaging, and serologic assays that employ crude, non-specific antigens. These methods suffer from high cost and inaccessibility, and lack reliability. Development of the cysticercosis-specific glycoprotein antigens and their use in immunoblot have given us a diagnostic tool with high sensitivity and exquisite specificity. As discussed here by Victor Tsang and Marianna Wilson, use of this assay in recent epidemiologic studies has demonstrated the serious impact of cysticercosis to public health and the economy of the pork industry.
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Taenia solium disease in humans and pigs: An ancient parasitosis disease rooted in developing countries and emerging as a major health problem of global dimensions
Article
  • Jan 2001
  • MICROBES INFECT
This article reviews current knowledge on human and porcine cysticercosis caused by Taenia solium. It highlights the conditions favorable for its prevalence and transmission, as well as current trends in research on its natural history, epidemiology, immunopathology, diagnosis, treatment and prevention. Our opinions on the most urgent needs for further research are also presented.
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An approach to correlate tandem mass spectral data of peptides with amino acid sequences in a protein database
Article
  • Nov 1994
A method to correlate the uninterpreted tandem mass spectra of peptides produced under low energy (10–50 eV) collision conditions with amino acid sequences in the Genpept database has been developed. In this method the protein database is searched to identify linear amino acid sequences within a mass tolerance of ± 1 u of the precursor ion molecular weight. A cross-correlation function is then used to provide a measurement of similarity between the mass-to-charge ratios for the fragment ions predicted from amino acid sequences obtained from the database and the fragment ions observed in the tandem mass spectrum. In general, a difference greater than 0.1 between the normalized cross-correlation functions of the first- and second-ranked search results indicates a successful match between sequence and spectrum. Searches of species-specific protein databases with tandem mass spectra acquired from peptides obtained from the enzymatically digested total proteins of E. coli and S. cerevisiae cells allowed matching of the spectra to amino acid sequences within proteins of these organisms. The approach described in this manuscript provides a convenient method to interpret tandem mass spectra with known sequences in a protein database.
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An Enzyme-Linked Immunoelectrotransfer Blot Assay and Glycoprotein Antigens for Diagnosing Human Cysticercosis (Taenia solium)
Article
  • Feb 1989
An enzyme-linked immunoelectrotransfer blot (EITB) assay was developed for immunodiagnosing human cysticercosis. The assay uses lentil-lectin, affinity-purified glycoprotein antigens. A battery of 532 serum and 46 cerebrospinal fluid (CSF) samples (148 cases of parasitologically confirmed cysticercosis, 54 healthy controls, and 18 types of heterologous infections [376 cases]) were used to ascertain the assay's efficacy. All but three of the samples from cases of confirmed cysticercosis were positive; none of the samples from healthy controls or heterologous infections reacted to any of the diagnostic bands. Thus, the assay is 98% sensitive and 100% specific. We identified seven major glycoprotein bands that are commonly recognized by virtually all serum and/or CSF samples from patients with confirmed cysticercosis. There was no significant difference in test performance when CSF was compared with serum. The EITB assay is highly reproducible and simple to perform, and the reagents (including the antigens blotted onto strips) are very stable.
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The Enzyme-Linked Immunoelectro-Transfer Blot Techniques (EITB) for Studying the Specificities of Antigens and Antibodies Separated by Gel Electrophoresis
Article
  • Feb 1983
  • METHOD ENZYMOL
This chapter describes the enzyme-linked immunoelectrotransfer blot techniques (EITB) for studying the specificities of antigens and antibodies separated by gel electrophoresis. The enzyme-linked immunoelectrotransfer blot technique (EITB) combines the high resolving power of gradient sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) and the high sensitivity of the enzyme-linked immunosorbent assay (ELISA) to produce an extremely powerful qualitative tool for studying antigen–antibody pairs. Using this procedure, antigens electrophoretically resolved on SDS–PAGE are transferred onto nitrocellulose or diazo sheets and identified by ELISA methods. The chapter discusses the general comments about the technique. The EITB is conducted in three stages: (a) the antigen mixture that can be extremely complex, such as solubilized whole cells, is first resolved by gel electrophoresis (two-dimensional gels can also be used); (b) the resolved gel is then electrophoretically blotted onto nitrocellulose sheets; and (c) the blotted nitrocellulose is then developed by ELISA.
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