INRA, UMR1282 Infectiologie et Santé Publique, F-37380 Nouzilly, France.
J Antimicrob Chemother. 2012 Oct;67(10):2354-60. doi: 10.1093/jac/dks251. Epub 2012 Jul 6.
To determine the complete nucleotide sequence of the multidrug resistance IncA/C plasmid pR55 from a clinical Klebsiella pneumoniae strain that was isolated from a urinary tract infection in 1969 in a French hospital and compare it with those of contemporary emerging IncA/C plasmids.
The plasmid was purified and sequenced using a 454 sequencing approach. After draft assembly, additional PCRs and walking reads were performed for gap closure. Sequence comparisons and multiple alignments with other IncA/C plasmids were done using the BLAST algorithm and CLUSTAL W, respectively.
Plasmid pR55 (170 810 bp) revealed a shared plasmid backbone (>99% nucleotide identity) with current members of the IncA/C(2) multidrug resistance plasmid family that are widely disseminating antibiotic resistance genes. Nevertheless, two specific multidrug resistance gene arrays probably acquired from other genetic elements were identified inserted at conserved hotspot insertion sites in the IncA/C backbone. A novel transposon named Tn6187 showed an atypical mixed transposon configuration composed of two mercury resistance operons and two transposition modules that are related to Tn21 and Tn1696, respectively, and an In0-type integron.
IncA/C(2) multidrug resistance plasmids have a broad host range and have been implicated in the dissemination of antibiotic resistance among Enterobacteriaceae from humans and animals. This typical IncA/C(2) genetic scaffold appears to carry various multidrug resistance gene arrays and is now also a successful vehicle for spreading AmpC-like cephalosporinase and metallo-β-lactamase genes, such as bla(CMY) and bla(NDM), respectively.
从 1969 年法国一家医院泌尿道感染患者分离的肺炎克雷伯菌临床株中，确定多药耐药 IncA/C 质粒 pR55 的完整核苷酸序列，并与当代新兴 IncA/C 质粒进行比较。
使用 454 测序方法对质粒进行纯化和测序。在草图组装后，通过额外的 PCR 和步行读取来进行缺口闭合。使用 BLAST 算法和 CLUSTAL W 分别进行序列比较和与其他 IncA/C 质粒的多重比对。
质粒 pR55（170810 bp）与当前广泛传播抗生素耐药基因的 IncA/C(2) 多药耐药质粒家族的成员共享质粒骨架（>99%核苷酸同一性）。然而，在 IncA/C 骨架的保守热点插入位点插入了两个可能从其他遗传元件获得的特定多药耐药基因簇。一种新型转座子 Tn6187 显示出一种非典型的混合转座子结构，由两个汞抗性操纵子和两个转位模块组成，分别与 Tn21 和 Tn1696 相关，以及一个 In0 型整合子。
IncA/C(2) 多药耐药质粒具有广泛的宿主范围，并与人类和动物肠道细菌中抗生素耐药性的传播有关。这种典型的 IncA/C(2) 遗传支架似乎携带各种多药耐药基因簇，现在也是传播 AmpC 样头孢菌素酶和金属β-内酰胺酶基因（如 bla(CMY)和 bla(NDM)）的成功载体。
