中国四省份禽肉中耶尔森菌的耐药性及其耐药基因研究

Antimicrobial susceptibility and drug-resistance genes of Yersinia spp. of retailed poultry in 4 provinces of China

目的 了解我国4省份禽肉中分离小肠结肠炎耶尔森菌、中间型耶尔森菌和弗氏耶尔森菌的耐药特征和耐药基因的携带情况。方法 本研究采用的22株小肠结肠炎耶尔森菌、2株中间型耶尔森菌和1株弗氏耶尔森菌来源于2016年全国污染物监测网，其中1株分离自宁夏回族自治区，3株分离自山东省，16株分离自河北省，5株分离自黑龙江省。采用肉汤稀释法测定25株分离菌对14类25种临床常用抗生素的药物敏感性，将菌株的全基因组序列与抗生素抗性基因数据库（ARDB）比对，对基因组中的耐药基因进行预测。结果 25株耶尔森菌对氨苄西林、阿莫西林/克拉维酸和头孢唑啉全部耐药，其中22株小肠结肠炎耶尔森菌中对头孢西丁、氨苄西林/舒巴坦、呋喃妥因和甲氧苄啶/磺胺甲噁唑的耐药率分别为63.7%（14株）、22.8%（5株）、4.6%和4.6%（1株）。25株菌全部耐3类及以上抗生素（多重耐药株），耐4类及以上抗生素的比例为64.0%（16株），且4株分离自鸡肉的小肠结肠炎耶尔森菌对头孢曲松、环丙沙星出现了中介耐药。25株菌株中有20株携带有相同的6种耐药基因（簇），分别为mdtG、ksgA、bacA、blaA、rosAB和acrB，有5株分离自新鲜鸡肉的小肠结肠炎耶尔森菌还携带有耐药基因dfrA1、catB2和ant3ia。结论 我国部分地区生禽肉中耶尔森菌的耐药性严重，携带有多种耐药基因。

Objective To monitor the antimicrobial resistance and drug-resistance genes of Yersinia enterocolitis, Y. intermedia and Y. frederiksenii recovered from retailed fresh poultry of 4 provinces of China.Methods The susceptibility of 25 isolated Yersinia spp. to 14 classes and 25 kinds of antibiotics was determined by broth microdilution method according to CLSI （Clinical and Laboratory Standards Institute）. The antibiotic resistance genes were predicted with antibiotic resistance genes database （ARDB） using whole genome sequences of Yersinia spp.Results In all 22 Y. enterocolitis tested, 63.7% （14 isolates）, 22.8% （5 isolates）, 4.6% and 4.6% of 1 isolates exhibited the resistance to cefoxitin, ampicillin-sulbactam, nitrofurantoin and trimethoprim-sulfamethoxazole, respectively. All the 25 isolates were multi-drug resistant to more than 3 antibiotics, while 64.0% of isolates were resistant to more than 4 antibiotics. A few Y. enterocolitis isolates of this study were intermediate to ceftriaxone and ciprofloxacin. Most Yersinia spp. isolates contained antibiotic resistance genes mdtG, ksgA, bacA, blaA, rosAB and acrB, and 5 isolates recovered from fresh chicken also contained dfrA1, catB2 and ant3ia.Conclusion The multi-drug resistant Yersinia spp. isolated from retailed fresh poultry is very serious in the 4 provinces of China, and their contained many kinds of drug-resistance genes.