Desarrollo de una técnica de inmunoelectrotransferencia "Westernblot" para la detección de anticuerpos contra componentes proteínicos de Salmonella Typhi

Abstract

Since its development, inmunoblotting has been widely used as a tool in molecular biology studies as well as in the diagnosis of infectious diseases. Traditionally the demostration of antibodies against Salmonella typhi has focussed in those against polysaccharide components specially related to somatic antigen "O". Very few works, if any, have been done to investigate antibodies against other antigens such as protoplasmic proteins. The paper presented hereby intends to demonstrate the presence of such antibodies in experimentally immunized rabbits as well in volunteers vaccinated with oral anti-typhoid fever vaccine (T y 21 a strain). A sonicate protein mixture from Salmonella typhi was separated into fractions by polyacrylaminde-SDS electrophoresis; after transfer to nitrocellulose membranes, bands were immuno-stained with sera fromrabbits immunized with the sonicate mixture, or with sera from volunteers before and after immunization with the vaccine strain T y21a. The immune-staihing was performed with enzymatic reactions, using either anti-rabbit IgG conjugated with alkaline phosphatase, or anti-human IgG conjugated with alkaline phosphatase. A 38 kd band was consistently seen with sera from immunized rabbits and with sera from the vaccinated volunteers. No such a band was Seen in the controls. No cross reactions were observed, suggesting that immunobloting could be a usefull technnique for detec tion of antibodies against Salmonella typhi.