Molecular characterization of the antimicrobial resistance of Riemerella anatipestifer isolated from ducks
Molecular characterization of the antimicrobial resistance of Riemerella anatipestifer isolated from ducks
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鸭疫里默氏菌耐药性的分子特征
DOI：
10.1016/j.vetmic.2012.03.005
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发表时间：
2012-08-17
影响因子：
3.3
通讯作者：
Zeng, Zhen-Ling
中科院分区：
文献类型：
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作者：
Sun, Na;Liu, Jian-Hua;Zeng, Zhen-Ling
采用琼脂稀释法测定了2008年和2010年在华南地区鸭源分离的103株鸭疫里默氏菌对23种抗菌药物的敏感性。103株鸭疫鼠分离株中链霉素、卡那霉素、庆大霉素、阿帕霉素、阿米卡星、新霉素、钠地酸和磺胺嘧啶的MIC50和MIC90值较高（32- >= 128 μ g/ml）。然而，在这些分离株中，氨苄西林和氟苯尼考的MIC90值相对较低（8 μ g/ml）。采用PCR检测抗性基因和整合子的存在。分别在1、2、24、35、11、4、67、16、26、10、6、9、36和2株分离株中检测到bla（TEM-1）、aph（3′）-VII、aadA1、aadA2、aac（3′）-IV、aac（3′）-IIc、aac（6′）-Ib、cat2、cmlA、floR、tet(A)、tet(B)、tet(C)、sul1和sul2基因。20株分离株含有一个或两个1类整合子，携带aadA2或aac(6')-II-catB3-aadA1基因盒。对43株纳啶酸mic值>= 32 μ g/ml的鸭疫鼠喹诺酮耐药决定区（QRDRs）进行突变分析，结果显示gyrA中最常见的突变位点为Ser83-Ile (n= 37)，其次为Asp87-His （n= 7）和Ser83-Arg （n= 5）。在5株环丙沙星MIC值为16 μ g/ml的分离株中观察到parC点突变（Arg120-Glu）。未检出质粒介导的喹诺酮类耐药基因。PFGE分析表明，多重耐药禽疫鼠分离株克隆传播发生在同一猪场或不同猪场之间。我们的研究结果首次报道了耐喹诺酮类药物耐药性的机制。(C) 2012 Elsevier B.V.版权所有
The antimicrobial susceptibility of 103 Riemerella anatipestifer isolates obtained from ducks during 2008 and 2010 in Southern China, to 23 antimicrobial agents was investigated using the agar dilution method. The MIC50 and MIC90 values of streptomycin, kanamycin, gentamicin, apramycin, amikacin, neomycin, nalidixic acid and sulfadimidine were high (32- >= 128 mu g/ml) among the 103 R. anatipestifer isolates. However, relatively low MIC90 values (8 mu g/ml) of ampicillin and florfenicol were observed among these isolates. The presence of resistance genes and integrons was determined using PCR. The genes bla(TEM-1), aph(3')-VII, aadA1, aadA2 aac(3')-IV, aac(3')-IIc, aac(6')-Ib, cat2, cmlA, floR, tet(A), tet(B), tet(C), sul1, and sul2 were detected in 1, 2, 24, 35, 11, 4, 67, 16, 26, 10, 6, 1, 9, 36 and 2 isolates, respectively. Twenty isolates contained one or two class 1 integrons carrying aadA2 or aac(6')-II-catB3-aadA1 gene cassette(s). Mutation analysis of the quinolone resistance-determining regions (QRDRs) of 43 R. anatipestifer isolates with nalidixic acid MICs >= 32 mu g/ml, showed that the most prevalent mutations in gyrA were those resulting in the amino acid exchanges Ser83-Ile (n= 37), followed by Asp87-His (n = 7) and Ser83-Arg (n 5). Point mutations in parC (Arg120-Glu) were observed in 5 isolates with a ciprofloxacin MIC of >16 mu g/ml. No plasmid-mediated quinolone resistance gene was detected. PFGE analysis showed that the clonal spread of multi-drug resistant R. anatipestifer isolates occurred in the same farm or between different farms. Our results reported, for the first time, the mechanism of quinolone resistance in R. anatipestfier. (C) 2012 Elsevier B.V. All rights reserved.