RT Journal Article T1 Antimicrobial susceptibility and genetic characterization of Trueperella pyogenes isolates from pigs reared under intensive and extensive farming practices A1 Galán-Relaño, Ángela A1 Gómez-Gascón, Lidia A1 Luque, Inmaculada A1 Barrero-Dominguez, Belén A1 Cardoso-Toset, Fernando A1 Tarradas, Carmen A1 Fernández-Garayzábal Fernández, José Francisco A1 Vela Alonso, Ana Isabel A1 Casamayor Sanz, Almudena AB Trueperella pyogenes is an opportunistic pathogen associated with a variety of diseases and responsible for important economic losses for pig production. Minimal Inhibitory Concentration (MIC) and Pulsed Field Gel Electrophoresis (PFGE) typing analysis were used to determine the MIC distribution and to genetically characterize a total of 180 T. pyogenes isolates obtained from slaughtered pigs reared under intensive (TpIN, n = 89) and extensive (TpEX, n = 91) farming practices. Low MIC90 values for penicillin and amoxicillin (0.008 and 0.06 μg/ml, respectively), ceftiofur, gentamicin and enrofloxacin (1 μg/ml, respectively) were obtained, so they could be of choice for the empiric treatment of T. pyogenes infections. Except for the penicillin, amoxicillin and ceftiofur, a statistically significant difference was observed in the MIC distribution of all antimicrobials analysed between TpIN and TpEX isolates. Also, MIC90 values were higher in TpIN than in TpEX isolates for neomycin and streptomycin (32 μg/ml vs 8 μg/ml), sulfamethoxazole/trimethoprim (30.4/1.6 μg/ml vs 1.90/0.10 μg/ml) and tylosin (≥1024 μg/ml vs 1 μg/ml). A relatively lower genetic diversity was detected in TpIN in comparison with TpEX isolates (GD 0.42 and GD 0.47, respectively). All isolates were distributed in three clusters (A, B, C). TpIN isolates were statistically associated with cluster A (P = 0.0002; OR 3.21; CI95 1.74–5.93), whereas the TpEX were distributed throughout the dendrogram, showing more genetic diversity. These data suggest that the antimicrobial susceptibility and genetic variability of the T. pyogenes isolates could be influenced by the management systems. SN 1873-2542 YR 2019 FD 2019 LK https://hdl.handle.net/20.500.14352/94011 UL https://hdl.handle.net/20.500.14352/94011 LA eng NO Ministerio de Agricultura, Pesca y Alimentación (20140020001824) DS Docta Complutense RD 10 sept 2024