Molecular characterisation of multidrug-resistant Salmonella enterica serotype Infantis from humans, animals and the environment in Italy
Molecular characterisation of multidrug-resistant Salmonella enterica serotype Infantis from humans, animals and the environment in Italy
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DOI：
10.1016/j.ijantimicag.2011.07.001
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发表时间：
2011-11-01
影响因子：
10.8
通讯作者：
Luzzi, Ida
中科院分区：
文献类型：
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作者：
Dionisi, Anna Maria;Lucarelli, Claudia;Luzzi, Ida
2005-2006年期间，意大利出现了从人源和非人源分离出的对氨苄西林(A)、氯霉素(C)、链霉素(S)、磺胺（Su）、四环素(T)、卡那霉素(K)和甲氧苄啶/磺胺甲恶唑（sst）耐药的肠沙门氏菌血清型婴儿菌株。本研究的目的是分析抗生素耐药的分子基础，并评价不同来源的多重耐药婴儿链球菌的克隆来源。本研究选取70株对抗菌药物敏感或耐药的婴儿链球菌。采用聚合酶链反应（PCR）和偶联实验对多重耐药菌株的耐药基因进行鉴定和定位。基于pcr的复制子分型对共轭质粒进行了表征。采用脉冲场凝胶电泳（PFGE）检测所有菌株，采用BioNumerics软件进行聚类分析。具有抗性(R)型acssutksst的菌株含有bla（TEM-1）、strA-B、sul2、tet(B)、catA1和aphA-1抗性基因，以及含有folA、catB3、aadA4和sul1基因盒的2.2 kb 1类整合子。一个独特的质粒，属于HI1不相容组，包含了所有的抗性基因。聚类分析表明，所有抗acssutksst菌株均属于一个大聚类(a)，遗传相似度为90%左右。含有所有抗性基因磁带的质粒的存在以及PFGE的分子分型表明，2005-2006年在意大利发生了婴幼儿s型acssutksst群的循环。具有多药耐药性的质粒的存在可能促进了一组类似分离株通过各种来源的传播。(C) 2011 Elsevier B.V.与International Society of Chemotherapy。版权所有。
During 2005-2006, Salmonella enterica serotype Infantis strains isolated from human and non-human sources and resistant to ampicillin (A), chloramphenicol (C), streptomycin (S), sulphonamide (Su), tetracycline (T), kanamycin (K) and trimethoprim/sulfamethoxazole (Sxt) emerged in Italy. The aim of this study was to analyse the molecular basis of antibiotic resistance and to evaluate the clonal origin of multiresistant S. Infantis strains isolated from different sources. Seventy S. Infantis strains, susceptible or resistant to antimicrobial drugs, were chosen for this study. Polymerase chain reaction (PCR) and conjugation experiments were performed to identify and localise the resistance genes in multidrug-resistant strains. PCR-based replicon typing was carried out for characterisation of conjugative plasmids. All strains were tested by pulsed-field gel electrophoresis (PFGE) according to the PulseNet protocol, and cluster analysis was performed using BioNumerics software. Strains with resistance (R)-type ACSSuTKSxt harboured bla(TEM-1), strA-B, sul2, tet(B), catA1 and aphA-1 resistance genes as well as a 2.2-kb class 1 integron containing folA, catB3, aadA4 and sul1 gene cassettes. A unique plasmid, belonging to the HI1 incompatibility group, harboured all the resistance genes. Cluster analysis showed that all ACSSuTKSxt-resistant strains belonged to a large cluster (A) with >90% genetic similarity. The presence of a plasmid harbouring all the resistance gene cassettes as well as molecular typing by PFGE demonstrated the circulation of a cluster of S. Infantis R-type ACSSuTKSxt during 2005-2006 in Italy. The presence of a plasmid conferring multidrug resistance could have facilitated the spread of a group of similar isolates through a variety of sources. (C) 2011 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.