Antimicrobial resistance in isolates of Salmonella spp. from pigs and the characterization of an S. Infantis gene cassette.
One hundred and seven Salmonella isolates of various serotypes were investigated for resistance to a panel of nine antimicrobial agents by standardized methods. Thirty four isolates were susceptible to the selected antimicrobial agents. Thirty-six (of 107) were resistant to three or more antimicrobial agents and defined as multidrug resistant (MDR). Salmonella Typhimurium was the most resistant serotype. All resistant isolates were examined for the presence of class 1 integrons. Thirty-two integron-associated gene cassettes (of varying sizes) were identified. A 1,000-bp amplicon similar to that flanking the distal region of the Salmonella Genomic Island (SGI)-1 in Salmonella Typhimurium was detected in a majority of the S. Typhimurium isolates in this study. In contrast, a 1,800-bp amplicon was identified in all Salmonella Infantis isolates. This amplicon was completely characterized in one isolate. The presence of class 1 integrons in Salmonella spp. in pigs may be important if these zoonotic pathogens were to enter the food chain.
O'Mahony
Rebecca
R
Center for Food Safety, School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
Saugy
Melanie
M
Leonard
Nola
N
Drudy
Denise
D
Bradshaw
Bernard
B
Egan
John
J
Whyte
Paul
P
O'Mahony
Michéal
M
Wall
Patrick
P
Fanning
Séamus
S
D000003:Abattoirs; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001483:Base Sequence; D015169:Colony Count, Microbial / Q000662:veterinary; D004269:DNA, Bacterial / Q000032:analysis / Q000737:chemistry*; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D024901:Drug Resistance, Multiple, Bacterial; D005784:Gene Amplification; D007494:Ireland / Q000453:epidemiology; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012475:Salmonella / Q000187:drug effects* / Q000235:genetics; D012481:Salmonella Infections, Animal / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology; D013552:Swine; D013553:Swine Diseases / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial