Department of Functional Biology, Section of Microbiology, University of Oviedo, Oviedo, Spain.
Plasmid. 2013 Jul;70(1):104-9. doi: 10.1016/j.plasmid.2013.03.002. Epub 2013 Mar 27.
pUO-StVR2 is a derivative of pSLT, the virulence plasmid specific of Salmonella enterica serovar Typhimurium, which confers multidrug resistance. This plasmid is widespread among closely related isolates of S. Typhimurium, and often coexists with other plasmids like pStR12. The latter belongs to incompatibility group IncI1, was assigned to ST48 by pMLST (plasmid multilocus sequence typing), and confers resistance to streptomycin/spectinomycin, chloramphenicol, trimethoprim and sulphonamides, with the responsible genes (aadA1/aadA2, cmlA1, dfrA12 and sul3) located on a sul3-class 1 integron. When using clinical isolates of S. Typhimurium containing one (pUO-StVR2) or both (pUO-StVR2 and pStR12) plasmids as donors and Escherichia coli K12 J53 resistant to rifampicin as recipient, the conjugation frequencies of pUO-StVR2 and pStR12 were 10⁻⁸ and 10⁻³-10⁻⁵ transconjugants/donor, respectively, while the transfer frequency of pUO-StVR2 increased 10² up to 10⁵ times through mobilization by pStR12, depending on the donor strain and experimental conditions. Mobilization of pUO-StVR2, a plasmid which encodes virulence and resistance functions, by compatible plasmids which coexist in the same bacterium can facilitate the spread of these properties in S. Typhimurium, one of the most common serovars of S. enterica.
pUO-StVR2 是沙门氏菌 Typhimurium 毒力质粒 pSLT 的衍生物,可赋予其多重耐药性。该质粒在沙门氏菌 Typhimurium 的密切相关分离株中广泛存在,并且经常与其他质粒如 pStR12 共存。后者属于不相容群 IncI1,通过 pMLST(质粒多位点序列分型)被分配到 ST48,对链霉素/壮观霉素、氯霉素、甲氧苄啶和磺胺类药物具有抗性,其负责基因(aadA1/aadA2、cmlA1、dfrA12 和 sul3)位于一个 sul3 类 1 整合子上。当使用含有一个(pUO-StVR2)或两个(pUO-StVR2 和 pStR12)质粒的沙门氏菌 Typhimurium 临床分离株作为供体,以及对利福平具有抗性的大肠杆菌 K12 J53 作为受体时,pUO-StVR2 和 pStR12 的接合频率分别为 10⁻⁸ 和 10⁻³-10⁻⁵转导子/供体,而通过 pStR12 的动员,pUO-StVR2 的转移频率增加了 10² 至 10⁵ 倍,这取决于供体菌株和实验条件。通过共存于同一细菌中的相容质粒对编码毒力和耐药性功能的 pUO-StVR2 的动员可以促进这些特性在沙门氏菌 Typhimurium 中的传播,沙门氏菌 Typhimurium 是沙门氏菌属中最常见的血清型之一。