| Abstrakt: |
Salmonella entericasubsp. entericaplays a role as a foodborne pathogen worldwide. The consumption of contaminated pork has been associated with human salmonellosis and the increase in antimicrobial resistance among Salmonellafrom pigs and pork products is a concern. A total of 225 Salmonellaisolates from feed mills, the lairage environment, and the intestinal contents of pigs and carcasses were investigated for their antimicrobial susceptibility. A MIC for ciprofloxacin was screened by agar dilution, and antimicrobial resistance genes were investigated by PCR assays. Among the tested isolates, 171 (76%) showed resistance to at least one antimicrobial agent, and 91 (40.4%) were multiresistant. Resistance occurred most frequently to tetracycline (54.5%), sulfonamides (39.6%), and streptomycin (33.7%). Thirty-two (94.1%) nalidixic acid-resistant isolates exhibited decreased susceptibility to ciprofloxacin. The resistance genes found were blaTEM(ampicillin), tet(A)(tetracycline), tet(B) (tetracycline/minocycline), sul1, sul2,and sul3(sulfonamides), catA1(chloramphenicol), floR(florfenicol/chloramphen- icol), strAand strB(streptomycin), aph(3')-Ia(kanamycin), aac (3)-IIaand aac (3)-IVa(apramycin/gentamicin), aadAvariant (streptomycin/spectinomycin), and dfrA1(trimethoprim). Salmonellaisolates from pig feces and carcasses displayed a higher frequency of resistance to most antimicrobials tested than isolates from feed mills. Common resistance gene profiles were found in isolates from the lairage and the intestinal content of pigs and carcasses, demonstrating that resistance genes selected on farms may be found in pork. |
