Inc A/C Plasmids Are Prevalent in Multidrug-Resistant Salmonella enterica Isolates
Inc A/C Plasmids Are Prevalent in Multidrug-Resistant Salmonella enterica Isolates
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DOI：
10.1128/aem.02228-08
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发表时间：
2009-04-01
影响因子：
4.4
通讯作者：
Meinersmann, Richard J.
中科院分区：
文献类型：
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作者：
Lindsey, Rebecca L.;Fedorka-Cray, Paula J.;Meinersmann, Richard J.
细菌质粒是染色体外双链DNA的片段，其可以包含对宿主生物体有益的多种基因，如负责抗菌素耐药性的基因。本研究的目的是表征收集的437沙门氏菌肠道分离株从不同的动物来源，其抗菌药物耐药表型和质粒复制子类型，并在某些情况下，脉冲场凝胶电泳（PFGE），努力了解更多关于多药耐药的分布与复制子类型。使用由三个多重PCR组成的基于PCR的复制子分型试验，根据肠杆菌科中26种已知质粒类型的不相容性（Inc）复制子类型检测其中18种。连锁分析是用遗传图谱、复制子类型、血清型和Inc A/C完成的。Inc A/C质粒在多重耐药分离株中普遍存在，但沙门氏菌鼠伤寒血清型除外。聚类分析的基础上PFGE的一个子集的216株显示155个独特的类型，这表明一个可变的人口，但不同的集群与公司A/C质粒的分离株是显而易见的。还观察到血清型与Inc复制子类型B/O、I1、Frep和HI 1的显著连锁。目前的研究表明，沙门氏菌，Inc A/C质粒和多重耐药基因的组合是非常古老的。我们的研究结果表明，一些菌株，特别是血清型鼠伤寒和密切相关的类型，可能曾经携带的质粒，但耐药基因转移到染色体与随后的质粒丢失。
Bacterial plasmids are fragments of extrachromosomal double-stranded DNA that can contain a variety of genes that are beneficial to the host organism, like those responsible for antimicrobial resistance. The objective of this study was to characterize a collection of 437 Salmonella enterica isolates from different animal sources for their antimicrobial resistance phenotypes and plasmid replicon types and, in some cases, by pulsed-field gel electrophoresis (PFGE) in an effort to learn more about the distribution of multidrug resistance in relation to replicon types. A PCR-based replicon typing assay consisting of three multiplex PCRs was used to detect 18 of the 26 known plasmid types in the Enterobacteriaceae based on their incompatibility (Inc) replicon types. Linkage analysis was completed with antibiograms, replicon types, serovars, and Inc A/C. Inc A/C plasmids were prevalent in multidrug-resistant isolates with the notable exception of Salmonella enterica serovar Typhimurium. Cluster analysis based on PFGE of a subset of 216 isolates showed 155 unique types, suggesting a variable population, but distinct clusters of isolates with Inc A/C plasmids were apparent. Significant linkage of serovar was also seen with Inc replicon types B/O, I1, Frep, and HI1. The present study showed that the combination of Salmonella, the Inc A/C plasmids, and multiple-drug-resistant genes is very old. Our results suggest that some strains, notably serovar Typhimurium and closely related types, may have once carried the plasmid but that the resistance genes were transferred to the chromosome with the subsequent loss of the plasmid.