Pan-European analysis shows stable, low antimicrobial resistance in most bovine and porcine respiratory tract pathogens

Aims To survey antibiotic susceptibility of bacteria causing bovine and porcine respiratory tract infections in eight European countries and to compare retrospectively the resistance percentages between the countries participating in the VetPath programs. Methods and results Non-replicate nasopharyngeal/nasal or lung swabs were collected by harmonized sampling from animals with acute respiratory signs during the period 2019–2020. Pasteurella multocida , Mannheimia haemolytica , Histophilus somni from cattle ( n = 307), and P. multocida , Actinobacillus pleuropneumoniae , Glaesserella parasuis , Bordetella bronchiseptica and Streptococcus suis from pigs ( n = 659) were isolated by standard methods. S. suis was also isolated from meningitis cases. Minimum Inhibitory Concentrations (MICs) were assessed following CLSI standards and interpreted using veterinary breakpoints where available. H. somni isolates were fully susceptible against all tested antibiotics. Resistance in bovine P. multocida and M. haemolytica was absent or low, except for tetracycline (29.7 and 19.6% resistance for the two bacteria, respectively). Low macrolide and spectinomycin resistance were observed for M. haemolytica (1.5–2.3%) contrary to P. multocida (8.3–22.1%). Similar susceptibility patterns were observed in pigs. Resistance in P. multocida , A. pleuropneumoniae and S. suis to ceftiofur, enrofloxacin, florfenicol, and penicillin was absent or