title: Design and evaluation of a recombinant multi-epitope antigen for serodiagnosis of Toxoplasma gondii infection in humans.
abstract: BACKGROUND
  Serological investigation remains the primary approach to achieve satisfactory results in Toxoplasma gondii identification. However, the accuracy of the native antigen used in the current diagnostic kits has proven to be insufficient as well as difficult to standardize, so significant efforts have been made to find alternative reagents as capture antigens. Consequently, multi-epitope peptides are promising diagnostic markers, with the potential for improving the accuracy of diagnostic kits. In this study, we described a simple, inexpensive and improved strategy to acquire such diagnostic markers. The study was aimed at producing novel synthetic protein consisting of multiple immunodominant epitopes of several T. gondii antigens.
  
  
  RESULTS
  To accomplish our goals, a single synthetic gene of approximately 456 bp, which encodes potential epitopes of T. gondii antigens, was successfully constructed using gene assembly PCR. The constructed gene was cloned into a pET32a expression vector and transformed into BL21 E. coli. The entire protein was successfully expressed and purified. Subsequently, the preliminary diagnostic performance of expressed protein was evaluated by developing IgG enzyme-linked immunosorbent assay (ELISA) and Western blot analysis using human sera. The results showed 100 % sensitivity and specificity.
  
  
  CONCLUSIONS
  A purified protein expressing multi-immunodominant epitopes of T. gondii was generated. Further studies are required to evaluate the immunogenicity in animal models and to verify the immuno-reactivity of USM.TOXO1 as a diagnostic antigen.
authors.affiliation: Department of Medical Microbiology & Parasitology, School of Medical Sciences, Universiti Sains Malaysia, 16150, Kubang Kerian, Kelantan, Malaysia. Khalid541983@yahoo.com.
authors.forename: Khalid
authors.initials: K
authors.lastname: Hajissa
authors.affiliation: Department of Medical Microbiology & Parasitology, School of Medical Sciences, Universiti Sains Malaysia, 16150, Kubang Kerian, Kelantan, Malaysia. robaiza@usm.my.
authors.forename: Robaiza
authors.initials: R
authors.lastname: Zakaria
authors.affiliation: Biomedicine Program, School of Health Sciences, Universiti Sains Malaysia, 16150, Kubang Kerian, Kelantan, Malaysia. rapeah@usm.my.
authors.forename: Rapeah
authors.initials: R
authors.lastname: Suppian
authors.affiliation: Department of Medical Microbiology & Parasitology, School of Medical Sciences, Universiti Sains Malaysia, 16150, Kubang Kerian, Kelantan, Malaysia. zeehaida@usm.my.
authors.forename: Zeehaida
authors.initials: Z
authors.lastname: Mohamed
mesh_terms: D000953:Antigens, Protozoan / Q000097:blood* / Q000235:genetics / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D000939:Epitopes / Q000097:blood / Q000235:genetics / Q000276:immunology; D006801:Humans; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods*; D014122:Toxoplasma / Q000235:genetics / Q000276:immunology*; D014123:Toxoplasmosis / Q000097:blood* / Q000175:diagnosis* / Q000469:parasitology
chemical_list: D000953:Antigens, Protozoan; D000939:Epitopes