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Human toxocariasis which is caused mainly by the larvae of Toxocara canis and Toxocara cati , is a worldwide zoonotic disease that can be a potentially serious human infection. The enzyme-linked immunosorbent assay (ELISA) using T. canis excretory–secretory (TES) antigens harvested from T. canis larvae is currently the serological test for confirming toxocariasis. An alternative to producing large amounts of Toxocara TES and improved diagnosis for toxocariasis is through the development of highly specific recombinant antigens such as the T. canis second stage larva excretory–secretory 30 kDa protein (recTES-30). The aim of this study was to evaluate the sensitivity and specificity of a rapid diagnostic kit (RDT, named as iToxocara kit) in comparison to recTES-30 ELISA in Serendah Orang Asli village in Selangor, Malaysia. A total of 133 subjects were included in the study. The overall prevalence rates by ELISA and RDT were 29.3% and 33.1%, respectively, with more positive cases detected in males than females. However, no association was found between toxocariasis and gender or age. The percentage sensitivity, specificity, positive predictive value and negative predictive value of RDT were 85.7%, 90.1%, 80% and 93.2%, respectively. The prevalence for toxocariasis in this population using both ELISA and RDT was 27.1% (36/133) and the K-concordance test suggested good agreement of the two tests with a Cohen's kappa of 0.722, P < 0.01. In addition, the followed-up Spearman rank correlation showed a moderately high correlation at R = 0.704 and P < 0.01. In conclusion, the RDT kit was faster and easier to use than an ELISA and is useful for the laboratory diagnosis of hospitalized cases of toxocariasis. [ABSTRACT FROM AUTHOR]

The Trichinella spiralis 31 kDa protein (Ts31) was screened from the excretory-secretory (ES) proteins of muscle larvae (ML) by immunoproteomics using serum from mice infected with T. spiralis at 18 days post infection (dpi). The aim of this study was to characterize the Ts31 protein and to evaluate the potential of the recombinant Ts31 protein (rTs31) for serodiagnosis of human trichinellosis. Ts31 gene was cloned and rTs31 was produced in an E. coli expression system. An anti-rTs31serum recognized the native protein migrating in a 25–55 kDa range by Western blotting of ML crude or ES antigens. Expression of Ts31 gene was observed at all developmental stages of T. spiralis (adult worms, newborn larvae, pre-encapsulated larvae and ML). An immunolocalization analysis identified Ts31 in the cuticle and stichocytes of the parasite. The sensitivity of rTs31-ELISA and ES antigen ELISA for detecting anti- Trichinella IgG antibodies in sera of patients with trichinellosis was 97.83% (45/46) and 86.78% (39/46), respectively ( P > 0.05); The specificity of rTs31-ELISA was 99.13% (114/115), which was significantly higher than 85.22% (98/115) of ES antigen ELISA ( P < 0.01). The rTs31 protein of T. spiralis could be considered as a potential diagnostic antigen for trichinellosis. [ABSTRACT FROM AUTHOR]

Abstract: Schistosomiasis remains a serious worldwide public health problem. Improving the diagnostic assay for surveillance and monitoring will contribute to hastening the possible elimination of the disease in endemic regions. Therefore, this study aims to develop magnetic affinity enzyme-linked immunoassay (MEIA) for serological diagnosis of schistosomiasis based on recombinant 26kDa glutathione-S-transferase of Schistosoma japonicum (rSj26GST). BALB/c mice infected with S. japonicum cercariae (40 per mouse) were used. After infecting for 6 weeks, the antibody was detected by MEIA. All of the infected mouse sera were effectively determined by MEIA. Compared with the enzyme-linked immunosorbent assay (ELISA), MEIA has a higher ratio of the mean positive value to the mean negative value (P/N) at the same dilution ratio (3.92 versus 2.66). MEIA was further applied for diagnosis of human schistosomiasis. Sera from 28 schistosomiasis-confirmed patients with low-intensity infection, 15 treated patients, and 20 non-endemic negative controls, were used to assess the assay. The results showed that MEIA and ELISA had similarity in positive detection rates. However, the higher P/N of MEIA was observed at the same dilution ratio. MEIA had high negative rate in detection of specific IgG in the treated patients. Moreover, there was no cross reaction with the sera of paragonimiasis patients. These results suggested that MEIA based on rSj26GST is a simple, rapid, convenient assay for the diagnosis of schistosomiasis. [Copyright &y& Elsevier]

Abstract: In order to evaluate the potential use of TS14 antigen in an enzyme-linked immunosorbent assay (ELISA) for immunodiagnosis of neurocysticercosis (NC), its open reading frame (ORF) was amplified by RT-PCR from mRNA isolated from Taenia solium cysticerci. The ORF was subcloned into the expression vector pET-28a, and was used to transform Escherichia coli BL21 (DE3) cells to produce TS14 antigen. The His-tagged expressed protein was purified on a nickel affinity column. Using the HIS TS14 as antigen, ELISA was positive for 100% of cerebrospinal fluid (CSF) and 97% of serum samples from NC patients. No positive results were observed with sera and CSF samples from control groups. Cross-reactivity with sera from patients with schistosomiasis and Chagas’ disease was not observed. Serum samples from patients with taeniasis were evaluated and 2 of 13 cases showed reactivity in this assay. Our data indicate the usefulness of HIS TS14 in ELISA for an accurate and rapid assay for diagnosis of NC and seroepidemiological studies. [Copyright &y& Elsevier]