Latex Particles Sensitized with Proteins of Leptospira interrogans for Application in Immunoagglutination Assays

PROCHETTO, SANTIAGO D.; VANASCO, NORMA B.; GONZALEZ, VERÓNICA D.G.; LOTTERSBERGER, JAVIER; GARCIA, VALERIA S.; GUGLIOTTA, LUIS M.

INTERNATIONAL JOURNAL OF POLYMERIC MATERIALS

TAYLOR & FRANCIS AS

Lugar: Londres; Año: 2017 p. 791 - 797

0091-4037

Physical adsorption and chemical coupling of recombinant proteins of Leptospirainterrogans onto polystyrene and core-shell carboxylated particles were respectively investigated with the aim of producing latex-protein complexes to be used in immunoagglutination assays able to detect the Leptospirosis disease in either humans or animals. To this effect, a proteinlysate of crude extracts was evaluated, and sensitizations were carried out at different pHs, with the antigenic proteins approach to the particles surface favoured at pH close to their isoelectric point. In the covalent coupling experiments, high fractions of proteins were chemically-bound to carboxyl groups on the particles surface and higher densities of linked proteins were obtained for particles exhibiting greater carboxyl group densities. The produced latex-protein complexes weretested in immunoagglutination assays, by turbidimetry and a visual method, from a panel that included positive and negative bovine, canine and human sera. The area under ROC curves was used as an index of accuracy. The complexes obtained by covalent coupling of proteins on the latex of higher density of carboxyl groups allowed an acceptable discrimination between the studied positive and negative sera.