Caracterización molecular de cepas del virus de la fiebre aftosa aisladas durante los años 1993-1994 en la Argentina / Molecular characterization of aphthous fever virus isolated during the years 1993-1994 in Argentina

Nucleotide sequence and phylogenetic analysis of the VP1 structural protein have been used extensively as diagnostic and epidemiological tools for foot and mouth disease virus (FMDV). In this report we have applied this methodology to the analysis of the VP1 coding sequence from FMDV strains isolated in Argentina during 1993-1994. The results demonstrated that the field isolates were related to the vaccine strains used at that time. However the involvement of the vaccine virus appeared to be different for outbreaks caused by FMD viruses type O or C. These data provide a database essential for determining the origin of new epizootics.

Expresión y caracterización de dos proteínas estructurales del virus de la diarrea viral bovina (VDVB) / Expression and characterization of 2 bovine viral diarrhea virus structural proteins (]BVDV)

The BVDV glycoproteins gp48 and gp53 were expressed in the baculovirus eukaryotic system. Both recombinant proteins were recognized in western blot analysis by monoclonal antibodies and polyclonal serum. Immunofluorescent test demonstrated that gp53 was localized on the cell surface whereas gp48 was in the cytoplasm. The expressed proteins were extracted by non-denaturing detergent treatment. Rabbit antiserum raised against gp53 recombinant protein efficiently neutralized the virus. These results demonstrate that the recombinant proteins have immunological properties similar to those of the native viral protein and that they can be useful as diagnostic reagents.

Comparación de distintos métodos para la medición de la respuesta inmune humoral de ratones vacunados con el virus de la fiebre aftosa / [Comparison of various methods for the measurement of the humoral immune response in mice vaccinated with aphthous fever virus]

Kinetics of the humoral immune primary response and seven-day secondary response of adult CF1 mice to FMDV O1 Campos adjuvanted in aluminium hydroxide-saponin (AHS) or in oil emulsion (OE) were evaluated by means of ELISA and passive hemagglutination (PH). Analysis of the response to AHS vaccine showed that ELISA measured maximal titres of primary response at 23 days post-vaccination (dpv), and at day 17 of secondary response, while PH detected maximal titres for primary as well as secondary response around day 60 pv. Mice immunized with OE vaccine studied by ELISA presented a plateau of primary response around 40 dpv, while secondary response was maximal around 80 dpv. The same sera tested by PH showed the highest titres for primary response on day 50 pv and secondary response was maximal on day 40 pv. A criterion for the evaluation of vaccination efficiency in the murine model is proposed based on the methods employed in the determination of antibody level.

Comparación de distintos métodos para la medición de la respuesta inmune humoral de ratones vacunados con el virus de la fiebre aftosa / [Comparison of various methods for the measurement of the humoral immune response in mice vaccinated with aphthous fever virus]

Kinetics of the humoral immune primary response and seven-day secondary response of adult CF1 mice to FMDV O1 Campos adjuvanted in aluminium hydroxide-saponin (AHS) or in oil emulsion (OE) were evaluated by means of ELISA and passive hemagglutination (PH). Analysis of the response to AHS vaccine showed that ELISA measured maximal titres of primary response at 23 days post-vaccination (dpv), and at day 17 of secondary response, while PH detected maximal titres for primary as well as secondary response around day 60 pv. Mice immunized with OE vaccine studied by ELISA presented a plateau of primary response around 40 dpv, while secondary response was maximal around 80 dpv. The same sera tested by PH showed the highest titres for primary response on day 50 pv and secondary response was maximal on day 40 pv. A criterion for the evaluation of vaccination efficiency in the murine model is proposed based on the methods employed in the determination of antibody level.

Neutralización del virus de la fiebre aftosa O1 Campos por anticuerpos inducidos por un péptido sintético / Neutraliztion of fost-and-mouth diseases virus O1 Campos by antibodies induced by synthetic peptide

Un hexadecapéptido correspondiente a la secuencia 144-159 de la proteína estructural VP1 del virus de la fiebre aftosa (CFA), cepa O1K, fue sintetizado por métodos químicos. El mismo, acoplado covalentemente a distintas proteínas portadoras, demostró su capacidad de inducir anticuerpos neutralizantes del VFA cepa O1 Campos (O1Ca) en ratones adultos. La protección fue del 100% cuando se lo acopló a la hemocianina de un molusco (KLH) y fue inoculado en cantidad de 60 microng, dividida en dos dosis y adyuvada con mezcla oleosa. Las proteínas utilizadas como portadoras: albúmina bovina, purificado proteico de Mycobacterium (PPD), gliadina y células de Brocelas produjeron una respuesta inmune menor que la KLH