Lin Cheng-Chung, Chen Ter-Hsin, Wang Yu-Chih, Chang Chao-Chin, Hsuan Shih-Ling, Chang Yi-Chih, Yeh Kuang-Sheng
Graduate Institute of Veterinary Pathobiology, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan.
J Food Prot. 2009 Jan;72(1):14-20. doi: 10.4315/0362-028x-72.1.14.
One hundred thirty-three Salmonella strains isolated from the viscera of swine, chicken, and carcasses of swine and chicken in Taiwan from 2004 to 2006 were identified to serotype level and analyzed for their susceptibility to ciprofloxacin. In total, 76 (57%) strains of the Salmonella isolates exhibited high-level resistance to ciprofloxacin, having MICs ranging from 16 to 64 microg/ml. DNA sequence analysis revealed that mutations in the quinolone resistance-determining regions of gyrA (Ser83Phe, Asp87Gly or Asp87Asn), parC (Ser80Arg, or Ser80Ile or Glu84Lys), and parE (Ser458Pro) genes were associated with the Salmonella strains that demonstrated resistance to ciprofloxacin. A mismatch amplification mutation assay (MAMA)-PCR was developed to identify mutations in parC at codons 80 and 84. Specific PCR products were only recovered from ciprofloxacin-resistant Salmonella strains but not from the susceptible strains. MAMA-PCR targeting the mutations in parC correlated with what DNA sequencing revealed. In conclusion, monitoring ciprofloxacin-resistant Salmonella from animal sources should be performed on a regular basis. MAMA-PCR targeting parC could provide a fast method for those laboratories interested in quickly characterizing the resistance profile and with little access to DNA sequencing facilities.
对2004年至2006年从台湾地区猪、鸡的内脏以及猪和鸡的 carcasses 中分离出的133株沙门氏菌菌株进行血清型鉴定，并分析它们对环丙沙星的敏感性。总共，76株（57%）沙门氏菌分离株对环丙沙星表现出高水平耐药，其 MIC 范围为16至64微克/毫升。DNA 序列分析表明，gyrA（Ser83Phe、Asp87Gly 或 Asp87Asn）、parC（Ser80Arg、Ser80Ile 或 Glu84Lys）和 parE（Ser458Pro）基因的喹诺酮耐药决定区的突变与对环丙沙星耐药的沙门氏菌菌株相关。开发了一种错配扩增突变分析（MAMA）-PCR 来鉴定 parC 基因第80和84密码子处的突变。仅从环丙沙星耐药的沙门氏菌菌株中回收了特异性 PCR 产物，而从敏感菌株中未回收。针对 parC 突变的 MAMA-PCR 与 DNA 测序结果相关。总之，应定期监测动物源环丙沙星耐药沙门氏菌。针对 parC 的 MAMA-PCR 可为那些希望快速表征耐药谱且很少有机会使用 DNA 测序设施的实验室提供一种快速方法。
