Papa-Ezdra R, Cordeiro N F, Di Pilato V, Chiarelli A, Pallecchi L, Garcia-Fulgueiras V, Vignoli R
Departamento de Bacteriología y Virología, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay.
Department of Surgical Sciences & Integrated Diagnostics (DISC), University of Genoa, Genoa, Italy.
J Glob Antimicrob Resist. 2021 Sep;26:37-41. doi: 10.1016/j.jgar.2021.03.031. Epub 2021 May 18.
We sequenced two IncA/C plasmids harbouring bla in Klebsiella pneumoniae clinical isolates and compared their antibiotic resistance islands.
Transconjugants were obtained from two clinical K. pneumoniae isolates harbouring bla. Plasmid DNA from transconjugants underwent short-read whole-genome sequencing, reads were assembled, and gaps were closed by PCR and sequencing. Determination of plasmid replicons, antibiotic resistance genes, identification and characterisation of insertion sequence (IS) elements, and comparison with publicly available plasmid sequences were performed.
bla was located in a complex class 1 integron In35::ISCR1::bla, inserted in two different transposons designated Tn7057 and Tn7058, that reside in the resistance islands of plasmids pUR-KP0923 and pUR-KP1025, respectively. The general modules of both transposons were In35::ISCR1::bla-Tn1000-like-Tn2*-ISKpn11-12-13 variable module-ΔTn21. In Tn7057 there was ΔIS10R-catA2 associated with an additional ISKpn13. Both plasmids belonged to IncC type 2 and ST3. pUR-KP0923 was 167 138 bp in length and had a 37 926-bp resistance island at position 4 (RI-4). Plasmid pUR-KP1025 was 168 128 bp with a RI-4 of 36 222 bp.
This report describes the molecular nature of two transposons (Tn7057 and Tn7058) harbouring bla that reside in IncC type 2 ST3 plasmids. These transposons mediate resistance to oxyimino-cephalosporins, gentamicin and, in the case of Tn7057, chloramphenicol. CTX-M-2 is an important extended-spectrum β-lactamase (ESBL) to South American epidemiology. It is remarkable that despite being only two plasmid sequences, the information revealed here could contribute to a better understanding of the resistance islands from IncC type 2 plasmids.
我们对肺炎克雷伯菌临床分离株中携带bla的两个IncA/C质粒进行了测序，并比较了它们的抗生素耐药岛。
从两个携带bla的肺炎克雷伯菌临床分离株中获得接合子。对接合子的质粒DNA进行短读长全基因组测序，组装 reads，并通过PCR和测序填补缺口。进行质粒复制子的测定、抗生素耐药基因的检测、插入序列（IS）元件的鉴定和表征，并与公开可用的质粒序列进行比较。
bla位于一个复杂的1类整合子In35::ISCR1::bla中，插入到两个不同的转座子中，分别命名为Tn7057和Tn7058，它们分别存在于质粒pUR-KP0923和pUR-KP1025的耐药岛中。两个转座子的一般模块为In35::ISCR1::bla-Tn1000样-Tn2 *-ISKpn11-12-13可变模块-ΔTn21。在Tn7057中，有与另一个ISKpn13相关的ΔIS10R-catA2。两个质粒均属于IncC 2型和ST3。pUR-KP0923长度为167138 bp，在位置4（RI-4）处有一个37926 bp的耐药岛。质粒pUR-KP1025为168128 bp，RI-4为36222 bp。
本报告描述了两个携带bla的转座子（Tn7057和Tn7058）的分子性质，它们存在于IncC 2型ST3质粒中。这些转座子介导对氧亚氨基头孢菌素、庆大霉素的耐药性，对于Tn7057来说，还介导对氯霉素的耐药性。CTX-M-2是南美流行病学中一种重要的超广谱β-内酰胺酶（ESBL）。值得注意的是，尽管这里只有两个质粒序列，但所揭示的信息有助于更好地了解IncC 2型质粒的耐药岛。
