Distribution of Toxoplasma serotypes among Colombian and French OT patients (OT-CO# and OT-FR#) were assessed for antibodies reacting to 5 strain-specific GRA6 and GRA7 polymorphic peptides derived from Type II or Type I/III parasites.

Peptide names were abbreviated as follows: “6” denoting peptides from GRA6; “7” from GRA7; “I/III” or “II” for the strain bearing the peptide allele; and “d” indicating a truncated diagnostic peptide. Reactivity at SAG1 served as a positive control to indicate the presence of anti-Toxoplasma antibodies. Type I/III infections produce antibodies that react with 1 or both 6-I/III and d6I/III peptides, Type II infections react with at least 1 of the 6-II, d6-II and 7-II peptides, Atypical (ATYP) infections identify strain-specific antibodies that react with both I/III and II peptides, or do not react (nonreactive “NR”) with any of the allele-specific peptides. For the purposes of statistical analyses, patients were classified as possessing either a Type II serotype or NE-II serotype (for all other reactivities). Fischer's exact test was applied for comparison between population and difference was highly significant (P*found with a majority of Type I alleles by genotyping; case COL#26**found with a combination of Type I, III, and atypical alleles by genotyping : case COL#38***6I/III refers to the C-terminal peptide from the Dense Granule protein GRA6 (peptide “CLHPERVNVFDY”)****D″ stands for a delimited version of the 6I/III peptide, by truncation of the terminal Y amino acid, used to confirm specificity*****SAG1 is a recombinant protein used to confirm seropositivity among the patient samples received for serotyping←Positive reactivity by ELISA-based assay (cut-off value = 1.4)