Monoclonal antibodies (MAb) against Taenia crassiceps and Taenia solium cysticerci were produced and showed cross-reactivity with a 14-kDa protein from T. solium and with 18-and 14-kDa proteins from T. crassiceps. These MAbs and antibodies from cerebrospinal fluid (CSF) as well as serum samples from patients with neurocysticercosis (NC) reacted with 18-and 14-kDa T. crassiceps proteins purified by immunoaffinity chromatography using a Sepharose column coupled with MAbs (anti-excretory/secretory or anti-vesicular fluid antigens). Immunoaffinity-purified 18-and 14-kDa proteins were used in the design of a diagnostic enzymelinked immunosorbent assay (ELISA) to detect antibodies in 23 CSF and 20 serum samples from patients with NC, showing 100% sensitivity. The test specificity was determined using 42 noninflammatory CSF samples and 70 inflammatory CSF samples from patients with other neurological disorders (OND), showing 100% and 99.1% (confidence interval, 97.3% to 100%) specificity, respectively. A false-positive CSF sample result in the OND group was from a human immunodeficiency virus-positive patient with meningoencephalitis. By using serum samples from 194 healthy individuals, the specificity was 100%. Analysis of an additional 16 serum samples from individuals with other parasitic diseases (13 with intestinal parasitosis and 3 with schistosomiasis) showed negative results. Three (10%) serum samples from patients with hydatidosis were positive in our ELISA and in ELISA with T. solium cysticerci antigens. Two of them were also positive by immunoblotting. The use of 18-and 14-kDa T. crassiceps immunoaffinity-purified proteins for detection of anti-cysticercus antibodies in CSF and/or serum samples using an ELISA system showed a good performance and high specificity for serum samples, dispensing with the use of confirmatory tests, such as immunoblotting, for checking specificity.

In order to evaluate the taeniosis-cysticercosis complex in a population of a peasants ' settlement, located at Teodoro Sampaio, state of São Paulo, Brazil (longitude 52°36'12", latitude 22°17'12") The taeniosis-cysticercosis complex is an important cause of morbidity and mortality, widespread not only in most underdeveloped countries, but also in industrialized ones (Raether & Hanel 2003). There is strong evidence supporting the high prevalence of Taenia infection in humans from resource-poor areas, especially in rural areas with deficient sanitation, low hygienic standards, and unusual customs, such as consumption of raw pork (Phiri et al. 2003).Taenia solium and Taenia saginata are two taenids of great economic and medical importance, causing bovine and porcine cysticercosis and taeniosis in humans. The encysted larva, known as cysticercus from T. saginata and T. solium are found in cattle and swine, respectively, and the adult tapeworm of T. saginata and T. solium are found in man. The cycle is completed when eggs in proglottids shed from the human tapeworm are disseminated to the environment through feces, followed by the ingestion by cattle or swine, and then the viable cysts are eaten by man in undercooked beef (Lees et al. 2002). People are also infected by ingestion of T. solium or T. saginata eggs by contact with carriers or contaminated foods. Cysticercosis is an infection caused by cysticercus, the larval stage of Cestoda Family Taeniidae. Neurocysticercosis (NC), the nervous-system form of cysticercosis is caused by larvae of tapeworm T. solium (Carpio 2002).In Brazil, several previous studies have shown that NC in humans is an important public-health problem; although, very few reports on the prevalence and distribution of porcine cysticercosis have been published (Sakai et al. 2001). In the state of São Paulo, the frequency of anti-T. solium cysticercus antibodies in humans was determined in few counties (Vaz et al. 1990, Bragazza et al. 2002. Nonetheless, studies about the prevalence of T. saginata infection in humans or the presence of T. saginata cysticercus in cattle are scarce (Ungar & Germano 1992). Dias et al. (1991) found in 311 samples of stools of humans living in the state of São Paulo an occurrence of 0.5% in Taenia sp. eggs; of which 273 were identified as T. saginata proglottidis.The ELISA screening test is commonly used for the serological diagnosis of cysticercosis, although it crossreacts with cestoda parasites such as Hymenolepis nana and Echinococcus granulosos (Garcia et al. 2003, Ishida et al. 2003. Low-molecular-weight glycoproteins obtained from T. solium by affinity chromatography, considerably improved the specificity of ELISA screening tests, but a large amount of antigens is required (Tsang et al. 1989). Recently, it has successfully been reported the use of low-molecular-weight peptides obtained from the vesicular fluid of T. crassiceps antigens (Tcra-VF) and T. crassiceps cysticercus glycoproteins (Tcra-GP and Tcra(18-14)-GP in ELISA and immunoblot assays , Ishida e...

Glycoproteins from the total vesicular fluid of Taenia crassiceps (VF-Tc) were prepared using three different purification methods, consisting of ConA-lectin affinity chromatography (ConA-Tc), preparative electrophoresis (SDS-PAGE) (14 gp-Tc), and monoclonal antibody immunoaffinity chromatography (18/14-Tc). The complex composition represented by the VF-Tc and ConA-Tc antigens revealed peptides ranging from 101- to 14-kDa and from 92- to 12-kDa, respectively. Immunoblotting using lectins confirmed glucose/mannose (glc/man) residues in the 18- and 14-kDa peptides, which are considered specific and immunodominant for the diagnosis of cysticercosis, and indicated that these fractions are glycoproteins. Serum antibodies from a patient with neurocysticercosis that reacted to the 14 gp band from T. crassiceps (Tc) were eluted from immunoblotting membranes and showed reactivity to 14 gp from Taenia solium. In order to determine the similar peptide sequence, the N-terminal amino acid was determined and analyzed with sequences available in public databases. This sequence revealed partial homology between T. crassiceps and T. solium peptides. In addition, mass spectrometry along with theoretical M(r) and pI of the 14 gp-Tc point suggested a close relationship to some peptides of a 150-kDa protein complex of the T. solium previously described. The identification of these common immunogenic sites will contribute to future efforts to develop recombinant antigens and synthetic peptides for immunological assays.

Background: The goal of this study was to estimate the seroprevalence of Toxocara spp., Toxoplasma gondii, and Taenia solium metacestode infection and determine some of the associated risk factors for people living in the Dona Carmen settlement, Pontal of Paranapanema, Sã o Paulo, Brazil. Methods: Serum samples from 194 subjects were tested and participants answered a questionnaire. An enzyme-linked immunosorbent assay (ELISA) system based on Toxocara spp. excretory-secretory antigens obtained from the cultured second-stage larvae of Toxocara canis or vesicular fluid (VF) antigen from Taenia crassiceps metacestode was used to detect anti-Toxocara spp. IgG and IgE and anti-T. solium metacestode, respectively. For cysticercosis, the reactive ELISA samples were assayed by Western blotting using 18 kDa and 14 kDa proteins purified from VF. For T. gondii-specific IgG and IgM antibodies, anti-SAG-1, GRA-1, and GRA-7 epitope specificity was determined by ELISA. Results: Toxoplasma gondii IgG antibodies were found in 102/194 individuals (52.6%) with increased infections in females (P 5 0.02) and those with #US$300 monthly income (P 5 0.01). Positive IgM antibodies were detected in 21/194 individuals (10.8%). Antibodies specific to Toxocara spp. were found in 28/194 subjects (14.4%). All the individuals with Toxocara spp. also had T. gondii-specific IgG antibodies. Taenia solium metacestode antibodies were detected in 11 subjects (5.7%), but none were reactive based on Western blotting. Conclusion: In spite of environmental, educational, and socioeconomic factors favoring parasite infection, the seropositivity rates of T. gondii, Toxocara spp., and T. solium metacestode-specific IgG antibodies are similar to the rates found in studies conducted in different populations in Brazil.

Seroprevalence of Toxocara and Taenia solium and risk factors for infection with these parasites were explored in a long-term rural settlement in São Paulo state, Brazil. An ELISA for the detection of anti-Toxocara IgG and IgE and anti-T. solium cysticerci was standardized using Toxocara excretory-secretory antigens (TES) obtained from the cultured second-stage larvae of T. canis and by vesicular fluid antigen from Taenia crassiceps cysticerci (VF). For cysticercosis, the reactive ELISA samples were assayed by Western blot using 18 kDa and 14 kDa proteins purified from VF. Out of 182 subjects, 25 (13.7%) presented anti-Toxocara IgG and a positive correlation between total IgE and the reactive index of specific anti-TES IgE (P=0.0265) was found amongst the subjects found seropositive for anti-Toxocara IgG. In these individuals 38.0% showed ocular manifestations. The frequency of anti-T. solium cysticerci confirmed by Western blot was 0.6%. Seropositivity for Toxocara was correlated with low educational levels and the owning of dogs. Embryonated eggs of Toxocara spp. were found in 43.3% of the analysed areas.

Seven swine were experimentally infected with Taenia solium eggs and blood samples from each animal were periodically collected. At the end of the experiment (t140) the animals did not show clinical aspects of cysticercosis or parasites in tongue inspection. All animals were slaughtered and cut into thin slices in searching for cysts. The number of cysts found in each animal varied from 1 to 85. Enzyme-linked immunosorbent assay (ELISA) tests for antibody (Ab) detection and for antigen (Ag) detection were performed, which presented respectively 71 and 57% of positivity. By immunoblot (IB), using 18/14 (T. crassiceps Ag) or lentil-lectin-purified glycoproteins from T. solium Ag (LLGP) as Ag, five (71%) and six (86%) animals were positive, respectively. The association between Ag-ELISA with any IB (18/14 or LLGP) allowed the detection of all animals at 140 days post-experimental infection (days p.e.i.). The use of IB 18/14 combined to the Ag-ELISA allowed the detection of all animals since 70 days p.e.i., and the association between IB LLGP and Ag-ELISA allowed the detection of all animals since 112 days p.e.i. While all animals could be considered healthy by conventional screening tests, the use of immunoassays for detecting Ab and Ag showed better accuracy; therefore it would be more useful than usual clinical examination for screening cysticercosis in slightly infected pigs. Key words: swine cysticercosis -larval antigens -antibodies -enzyme-linked immunosorbent assay -immunoblotCysticercosis is a frequent infection in pigs and humans of developing countries. The cyst is the larval stage in the tissue of pigs that ingested viable eggs of Taenia solium. When humans ingest raw or undercooked pork meat containing T. solium cysts, they develop adult tapeworm in their small intestine (Garcia & del Bruto 2000, Verastegui et al. 2003. The contact of swine and people with human feces, the lack of pork meat inspection, and the consumption of uncooked or undercooked pork meat are factors promoting and maintaining such disease transmission (Sarti et al. 1988, Garcia et al. 1991, PrestesCarneiro et al. 2006.The inspection of pork meat for human consumption, showing about 70% of sensitivity , Ngowi et al. 2004, reduces the transmission risk mainly when animals present high degree of infection, which is more likely to occur in clandestinely raised animals. On the other hand, the inspection in low parasite burden animals showed to be less efficient since a detailed postmortem exam of the meat would cause commercial losses (Gonzalez et al. 1990, Pinto et al. 2000.Immunoassays for antibody (Ab) detection can be useful on a stage previous then slaughter, identifying the non-infected animals from those probably infected. Several authors have being using enzyme-linked immunosorbent assay (ELISA) and immunoblot (IB) in serum samples from naturally infected animals (Gonzalez et al. 1990, Pathak et al. 1994, Sciutto et al. 1998) and experimentally infected animals (Aluja et al. 1996, Sciutto et al. 1998) with sensitivity and specifi...

INTRODUCTION: Human serofrequency of antibodies against Taenia solium antigens was determined and risk factors for cysticercosis transmission were identified. METHODS: Individuals (n=878) from periurban and rural locations of Lages, SC, were interviewed to gather demographic, sanitary and health information. Interviews and blood sample collections by finger prick on Whatman filter paper were performed from August 2004 to May 2005. Observation determined that 850 samples were suitable for analysis and were tested by ELISA using vesicular fluid of Taenia crassiceps heterologous antigen. To ensure the reliability of the results, 77 samples of the dried blood were matched with sera. The reactive samples were submitted to a serum confirmatory immunoblot (IB) test using purified Taenia crassiceps glycoproteins. RESULTS: The ELISA results for the dried blood and serum samples were statistically consistent. ELISA was positive in 186 (21.9%) out of 850 individuals. A group of 213 individuals were asked to collect vein blood for IB (186 with positive result in ELISA and 27 with inappropriate whole blood samples) and 130 attended the request. The IB was positive in 29 (3.4%) out of 850 individuals. A significant correlation (p = 0.0364) was determined among individuals who tested positive in the IB assay who practiced both pig rearing and kitchen gardening. CONCLUSIONS: ELISA with dried blood eluted from filter paper was suitable for cysticercosis population surveys. In Lages, human infection was associated with pig rearing and kitchen gardening. The prevalence index was compatible with other Latin American endemic areas.

Seven swine were experimentally infected with Taenia solium eggs and blood samples from each animal were periodically collected. At the end of the experiment (t140) the animals did not show clinical aspects of cysticercosis or parasites in tongue inspection. All animals were slaughtered and cut into thin slices in searching for cysts. The number of cysts found in each animal varied from 1 to 85. Enzyme-linked immunosorbent assay (ELISA) tests for antibody (Ab) detection and for antigen (Ag) detection were performed, which presented respectively 71 and 57% of positivity. By immunoblot (IB), using 18/14(T. crassiceps Ag) or lentil-lectin-purified glycoproteins from T. solium Ag (LLGP) as Ag, five (71%) and six (86%) animals were positive, respectively. The association between Ag-ELISA with any IB (18/14 or LLGP) allowed the detection of all animals at 140 days post-experimental infection (days p.e.i.). The use of IB 18/14 combined to the Ag-ELISA allowed the detection of all animals since 70 days p.e.i., and the association between IB LLGP and Ag-ELISA allowed the detection of all animals since 112 days p.e.i. While all animals could be considered healthy by conventional screening tests, the use of immunoassays for detecting Ab and Ag showed better accuracy; therefore it would be more useful than usual clinical examination for screening cysticercosis in slightly infected pigs.