Transcriptomics of Haemophilus (Glässerella) parasuis serovar 5 subjected to culture conditions partially mimetic to natural infection for the search of new vaccine antigens

11 p.Haemophilus (Glässerella) parasuis is the etiological agent of Glässer’s disease in pigs. Control of this disorder has been traditionally based on bacterins. The search for alternative vaccines has focused mainly on the study of outer membrane proteins. This study investigates the transcriptome of H. (G.) parasuis serovar 5 subjected to in vitro conditions mimicking to those existing during an infection (high temperature and iron-restriction), with the aim of detecting the overexpression of genes coding proteins exposed on bacterial surface, which could represent good targets as vaccine candidates. The transcriptomic approach identified 13 upregulated genes coding surface proteins: TbpA, TbpB, HxuA, HxuB, HxuC, FhuA, FimD, TolC, an autotransporter, a protein with immunoglobulin folding domains, another large protein with a tetratricopeptide repeat and two small proteins that did not contain any known domains. Of these, the first six genes coded proteins being related to iron extraction. Six of the proteins have already been tested as vaccine antigens in murine and/or porcine infection models and showed protection against H. (G.) parasuis. However, the remaining seven have not yet been tested and, consequently, they could become useful as putative antigens in the prevention of Glässer’s disease. Anyway, the expression of this seven novel vaccine candidates should be shown in other serovars different from serovar 5.S

Essential oil of ocotea odorifera: An alternative against sitophilus zeamais

Nowadays, the maize weevil Sitophilus zeamais-Motsch 1855 is the most relevant pest found during storage of maize grains. Aiming at protecting the agricultural crops, high amounts of synthetic pesticides are used around the world. In this sense, this work aimed at evaluating the insecticidal and repellent effect of essential oil of Ocotea odorifera (Vellozo) Rohwer (Lauraceae) (O. odorifera (sassafras)) leaves against the maize weevil in maize grains. The essential oil's chemical composition showed that sassafras contains camphor (43%) and safrole (42%) as major compounds. Our results show that sassafras oil was insecticidal and repellent to maize weevil. About 100% mortality was achieved using a concentration of 0.32μl cm-2, after 24 h of exposure. The LD50 value was 14.1μl or 0.09μl cm-2 and the study of the effect on insect mortality at the lethal doses (LD50) showed that after 72h mortality was 100%. The values of the preference index varied from -0.39 (0.065μl cm-2) to -0.63 (0.659μl cm-2), demonstrating that the plant oil presents repellent activity. The repellency bioassay simulating small bins showed the repellent effect level from 0.64 (0.36μl cm-3) to 0.94 (2.9μl cm-3). The essential oil of sassafras presented insecticidal and repellency against maize weevil. Although from an economical point of view synthetic chemicals are still more frequently used as repellents, natural products (essential oils) have the potential to provide efficient and safer repellents for humans and the environment