RT info:eu-repo/semantics/article T1 Brazilian Clinical Strains of Actinobacillus pleuropneumoniae and Pasteurella multocida: Capsular Diversity, Antimicrobial Susceptibility (In Vitro) and Proof of Concept for Prevention of Natural Colonization by Multi-Doses Protocol of Tildipirosin A1 Satomi Kuchiishi, Suzana A1 Ramos Prigol, Simone A1 Bresolin, Eduarda A1 Fernandes Lenhard, Bianca A1 Pissetti, Caroline A1 García Iglesias, María José A1 Gutiérrez Martín, César Bernardo A1 Martínez Martínez, Sonia A1 Kreutz, Luiz Carlos A1 Frandoloso, Rafael A2 Sanidad Animal K1 Veterinaria K1 Actinobacillus pleuropneumoniae K1 Pasteurella multocida K1 Glaesserella parasuis K1 Typing K1 Virulence genes K1 Antimicrobial susceptibility pattern K1 Tildipirosin K1 Colonization K1 Pig K1 3109 Ciencias Veterinarias AB [EN] One hundred Actinobacillus pleuropneumoniae (App) and sixty Pasteurella multocida subsp. multocida serogroup A (PmA) isolates were recovered from porcine pneumonic lungs collected from eight central or southern states of Brazil between 2014 and 2018 (App) or between 2017 and 2021 (PmA). A. pleuropneumoniae clinical isolates were typed by multiplex PCR and the most prevalent serovars were 8, 7 and 5 (43, 25% and 18%, respectively). In addition, three virulence genes were assessed in P. multocida isolates, all being positive to capA (PmA) and kmt1 genes, all negative to capD and toxA, and most of them (85%) negative to pfhA gene. The susceptibility of both pathogens to tildipirosin was investigated using a broth microdilution assay. The percentage of isolates susceptible to tildipirosin was 95% for App and 73.3% for PmA. The MIC50 values were 0.25 and 1 μg/mL and the MIC90 values were 4 and >64 μg/mL for App and PmA, respectively. Finally, a multiple-dose protocol of tildipirosin was tested in suckling piglets on a farm endemic for both pathogens. Tildipirosin was able to prevent the natural colonization of the tonsils by App and PmA and significantly (p < 0.0001) reduced the burden of Glaesserella parasuis in this tissue. In summary, our results demonstrate that: (i) tildipirosin can be included in the list of antibiotics to control outbreaks of lung disease caused by App regardless of the capsular type, and (ii) in the case of clinical strains of App and PmA that are sensitive to tildipirosin based on susceptibility testing, the use of this antibiotic in eradication programs for A. pleuropneumoniae and P. multocida can be strongly recommended. PB MDPI LK https://hdl.handle.net/10612/18449 UL https://hdl.handle.net/10612/18449 NO Kuchiishi, S. S., Ramos Prigol, S., Bresolin, E., Fernandes Lenhard, B., Pissetti, C., García-Iglesias, M.-J., Gutiérrez-Martín, C.-B., Martínez-Martínez, S., Kreutz, L. C., & Frandoloso, R. (2023). Brazilian Clinical Strains of Actinobacillus pleuropneumoniae and Pasteurella multocida: Capsular Diversity, Antimicrobial Susceptibility (In Vitro) and Proof of Concept for Prevention of Natural Colonization by Multi-Doses Protocol of Tildipirosin. Antibiotics, 12(12). https://doi.org/10.3390/ANTIBIOTICS12121658 DS BULERIA. Repositorio Institucional de la Universidad de León RD 27-jun-2024