Lopes Graciela Volz, Pissetti Caroline, da Cruz Payão Pellegrini Débora, da Silva Luis Eduardo, Cardoso Marisa
Departamento de Medicina Veterinária Preventiva, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil 90540-000.
Faculdade de Medicina Veterinária, Universidade Federal do Pampa, Campus Uruguaiana, Brazil 97500-970.
J Food Prot. 2015 Feb;78(2):407-13. doi: 10.4315/0362-028X.JFP-14-274.
Salmonella enterica subsp. enterica plays 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 Salmonella from pigs and pork products is a concern. A total of 225 Salmonella isolates 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/chloramphenicol), strA and strB (streptomycin), aph(3')-Ia (kanamycin), aac(3)-IIa and aac(3)-IVa (apramycin/gentamicin), aadA variant (streptomycin/spectinomycin), and dfrA1 (trimethoprim). Salmonella isolates 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.
肠炎沙门氏菌肠炎亚种在全球范围内作为食源性病原体发挥作用。食用受污染的猪肉与人类沙门氏菌病有关，猪和猪肉产品中沙门氏菌的抗菌药物耐药性增加令人担忧。对来自饲料厂、待宰环境以及猪和胴体肠道内容物的225株沙门氏菌分离株进行了抗菌药物敏感性调查。通过琼脂稀释法筛选环丙沙星的最低抑菌浓度（MIC），并通过PCR检测抗菌药物耐药基因。在测试的分离株中，171株（76%）对至少一种抗菌药物耐药，91株（40.4%）为多重耐药。对四环素（54.5%）、磺胺类药物（39.6%）和链霉素（33.7%）的耐药最为常见。32株（94.1%）对萘啶酸耐药的分离株对环丙沙星的敏感性降低。发现的耐药基因有blaTEM（氨苄青霉素）、tet(A)（四环素）、tet(B)（四环素/米诺环素）、sul1、sul2和sul3（磺胺类药物）、catA1（氯霉素）、floR（氟苯尼考/氯霉素）、strA和strB（链霉素）、aph(3')-Ia（卡那霉素）、aac(3)-IIa和aac(3)-IVa（阿普拉霉素/庆大霉素）、aadA变体（链霉素/壮观霉素）以及dfrA1（甲氧苄啶）。来自猪粪便和胴体的沙门氏菌分离株对大多数测试抗菌药物的耐药频率高于来自饲料厂的分离株。在来自待宰区以及猪和胴体肠道内容物的分离株中发现了常见的耐药基因谱，表明在农场中选择的耐药基因可能存在于猪肉中。
