Infectious bacterial enteritis causes severe losses to the swine industry worldwide. The objective of this study was to determine the epidemiology of bacterial agents that are associated with the occurrence of diarrhea in pigs at different age groups, and to verify the profile of resistance of strains of Escherichia coli and Salmonella spp to the main antimicrobial agents. The main bacterial species diagnosed were Escherichia coli, Clostridium spp, Salmonella spp, Brachyspira hyodysenteriae, Brachyspira pilosicoli and Lawsonia intracellularis. The E. coli virulence factors of higher prevalence in preweaning piglets were F5 / (K99) 20%, F6 / (987P) 16.3%, F42 6.8% and F41 5.7%, whereas at the nursery and with finishing pigs, the prevalent strain was the fimbria F4 (K88) 11.2% e 5.4%, respectively. E. coli and Salmonella spp were highly resistant to oxytetracycline (94%) and tetracycline (90%), with the former having a low resistance to neomycin (55%) and ceftiofur (57%), and the latter to gentamicin (3.5%) and amoxicillin (4.8%).
swine; digestive system; resistance to antimicrobials; diarrhea; virulence factors