Antimicrobial resistance patterns of Salmonella isolated from finishing pigs and environmental samples

The aim of this study was to determine the antimicrobial resistance patterns of Salmonella isolates from pigs and environmental samples collected from modern swine facilities in Brazil. Sixteen samples from a total of 1,026 were positive to Salmonella and six serotypes were identified: Salmonella Typhimurium (1), Salmonella Agona (5), Salmonella Sandiego (4), Salmonella Rissen (1), Salmonella Senftenberg ( 4) and Salmonella Javiana (I). Resistance patterns were different among serotypes, but different isolates from a single serotype had the same antimicrobial pattern. The highest percentage of resistance was to tetracycline (100%), streptomycin (100%), nalidixic acid (100%), cefotaxime (12.5) and tobramycin ( 12.5). All serotypes were I 00% susceptible to ceftriaxone, norfloxacin, ciprofloxacin, ampicillin, gentamycin and chloramphenicol. Intermediate resistance to neomycin (93.5%), amikacin (12.5%) and trimethoprim (12.5%) was seen. The high resistance to tetracycline and streptomycin may be due to its extensive use in pig production