Area de Bioquímica y Biología Molecular, Universidad de La Rioja, 26006 Logroño, Spain.
Int J Antimicrob Agents. 2010 May;35(5):492-6. doi: 10.1016/j.ijantimicag.2010.01.012. Epub 2010 Feb 25.
The prevalence and characterisation of integrons and the genetic environment of sulphonamide resistance genes were studied in 135 Escherichia coli isolates recovered from blood cultures in a Spanish hospital during 2007. Class 1 and 2 integrons were identified in 54 isolates (intI1, 52 isolates; intI2, 1 isolate; and intI1+intI2, 1 isolate). Of the 53 intI1-positive isolates, 36 (67.9%) contained the classic class 1 integron including the qacEDelta1-sul1 region, and 11 different gene cassette arrangements were demonstrated in 33 of these isolates. Seventeen intI1-positive isolates lacked the qacEDelta1-sul1 region, and 8 gene cassette arrangements were demonstrated in 12 of these isolates. Seventy-one isolates showed a sulphonamide-resistant phenotype, 63 of which contained sul genes. The sul1 gene was associated with intI1 in 36 of 42 sul1-positive isolates, and the sul3 gene was associated with non-classic class 1 integrons in 5 of 7 sul3-positive isolates. Finally, sul2 was found associated with strA-strB genes in 32 of 35 sul2-positive isolates, identifying 11 genetic structures, 1 of them presenting the IS150 element disrupting the strB gene; this structure was included in GenBank with accession no. FJ705354. Almost one-half of the E. coli isolates from blood cultures contained integrons and sul genes. Moreover, sul genes were detected in different structures, one of them new, and could be important determinants in antibiotic resistance dissemination.
135 株 2007 年从西班牙一家医院血培养中分离的大肠埃希菌中，研究了整合子的流行情况及其特征，以及磺胺类耐药基因的遗传环境。在 54 株分离株中鉴定出了 1 类和 2 类整合子（intI1，52 株；intI2，1 株；intI1+intI2，1 株）。在 53 株 intI1 阳性分离株中，36 株（67.9%）含有经典 1 类整合子，包括 qacEDelta1-sul1 区，在其中 33 株分离株中证实了 11 种不同的基因盒排列。17 株 intI1 阳性分离株缺乏 qacEDelta1-sul1 区，在其中 12 株分离株中证实了 8 种基因盒排列。71 株分离株表现出磺胺类耐药表型，其中 63 株含有 sul 基因。在 42 株 sul1 阳性分离株中，sul1 基因与 intI1 相关，在 5 株 sul3 阳性分离株中，sul3 基因与非经典 1 类整合子相关。最后，在 32 株 sul2 阳性分离株中发现 sul2 与 strA-strB 基因相关，确定了 11 种遗传结构，其中 1 种结构包含破坏 strB 基因的 IS150 元件；该结构包含在 GenBank 中，登录号为 FJ705354。血培养中分离的近一半大肠埃希菌含有整合子和 sul 基因。此外，还在不同的结构中检测到了 sul 基因，其中一种是新的，可能是抗生素耐药性传播的重要决定因素。
