RT info:eu-repo/semantics/article T1 Altered indirect hemagglutination method for easy serotyping of Haemophilus parasuis A1 Lorenson, Monique Salete A1 Miani, Michela A1 Guizzo, João A1 Barasoul, B. A1 Martínez Martínez, Sonia A1 Rodríguez Ferri, Elías Fernando A1 Gutiérrez Martín, César Bernardo A1 Kreutz, Luiz Carlos A1 Frandoloso, Rafael A2 Sanidad Animal K1 Sanidad animal K1 Haemophilus parasuis K1 Tannic acid K1 Indirect hemagglutination K1 Serotyping K1 Diagnosis AB Glässer’s disease is an emergent bacterial disease that affects swine husbandries worldwide causingimportant economic losses. The aetiological agent, Haemophilus parasuis, is currently divided in fifteenserovars but an increasing number of non-typeable serovars have been reported. Indirecthemagglutination (IHA) is indicated as a serotyping method for H. parasuis. In the present study, wedescribe an additional step that aims to work around a possible obstacle in the original protocol that maycompromise the outcome of this assay. We observed that the choice of anticoagulant for blood collectioninfluences and/or impairs spontaneous adsorption of H. parasuis antigens on sheep red blood cells(SRBCs). However, regardless of the anticoagulant used, chemical treatment of SRBCs with tannic acidinduces a stable antigen adsorption (sensitization step). The addition of 1% BSA to SRBCs washingbuffer and to antisera dilution augments IHA specificity. Tannic acid treated SRBCs combined withthermo-resistant H. parasuis antigens increases the assay resolution. Thus, our results demonstrate animprovement in the technique of H. parasuis serotyping that will prove valuable to understand Glässer’sdisease epidemiology and to better characterize serovars involved in outbreaks PB FEPMVZ Editora YR 2017 FD 2017-07-26 LK http://hdl.handle.net/10612/6455 UL http://hdl.handle.net/10612/6455 NO Arquivo Brasileiro de Medicina Veterinária e Zootecnia, 2017, vol. 69, n. 1 NO P. 15-21 DS BULERIA. Repositorio Institucional de la Universidad de León RD 29-mar-2024