Diversity of gene cassette promoter variants of class 1 integrons in uropathogenic Escherichia coli.
Diversity of gene cassette promoter variants of class 1 integrons in uropathogenic Escherichia coli.
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DOI：
10.1007/s00284-013-0399-1
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发表时间：
2013-11-01
影响因子：
2.6
通讯作者：
Lu, Yuan
中科院分区：
文献类型：
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作者：
Wei, Quhao;Jiang, Xiaofei;Lu, Yuan
1类整合子在细菌间抗生素抗性基因的出现和水平转移中发挥重要作用。 1类整合子的基因盒启动子变体Pc或Pc-P2不仅驱动下游基因盒的转录，还与捕获外源基因盒的切除和整合效率相关。在这项研究中，分析了 132 种尿路致病性大肠杆菌菌株中 1 类整合子的 Pc 或 Pc-P2 变异的多样性及其与抗生素耐药性表型的关联。在 95 个（72%）菌株中检测到 1 类整合子。检测到 16 个不同的基因盒、11 个不同的基因盒阵列和 6 个不同的 Pc 或 Pc-P2 变体。最常见的基因盒是那些赋予甲氧苄啶、氨基糖苷类和氯霉素抗性的基因盒。最常见的启动子是 PcH1，这是一种相对较弱的启动子。某些基因盒阵列或基因盒主要与不同菌株中的相同Pc或Pc-P2相关。与具有相对弱启动子的菌株相比，具有相对强启动子的1类整合子菌株对阿米卡星、氯霉素和妥布霉素具有更高的耐药率或更高的MIC(50)。据我们所知，这是首次报道尿路致病性大肠杆菌菌株中 1 类整合子 Pc 或 Pc-P2 变异的多样性。
Class 1 integrons play important roles in the emergence and horizontal transfer of antibiotic resistance genes among bacteria. The gene cassette promoter variants Pc or Pc-P2 of class 1 integrons not only drive the transcription of downstream gene cassettes, they also correlate with the excision and integration efficiency of the capture exogenous gene cassettes. In this study, the diversity of Pc or Pc-P2 variants of class 1 integrons and their association with antibiotic resistance phenotypes were analyzed in 132 uropathogenic Escherichia coli strains. Class 1 integrons were detected in 95 (72 %) strains. Sixteen different gene cassettes, 11 different gene cassette arrays and six different Pc or Pc-P2 variants were detected. The most prevalent gene cassettes were those that conferred resistance to trimethoprim, aminoglycosides, and chloramphenicol. The most prevalent promoter was PcH1, a relatively weak promoter. Certain gene cassette arrays or gene cassettes were mainly associated with the same Pc or Pc-P2 in different strains. Strains harboring class 1 integrons with relatively strong promoters had higher resistance rates to, or higher MIC(50) for, amikacin, chloramphenicol and tobramycin than those with relatively weak promoters. To the best of our knowledge, this is the first report of the diversity of class 1 integron Pc or Pc-P2 variants in uropathogenic E. coli strains.