Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK.
Microbiology (Reading). 2023 Apr;169(4). doi: 10.1099/mic.0.001324.
is a facultative anaerobe found in a wide range of environments. Commonly described as the laboratory workhorse, is one of the best characterized bacterial species to date, however much of our understanding comes from studies involving the laboratory strain K-12. Resistance-nodulation-division efflux pumps are found in Gram-negative bacteria and can export a diverse range of substrates, including antibiotics. K-12 has six RND pumps; AcrB, AcrD, AcrF, CusA, MdtBC and MdtF, and it is frequently reported that all strains possess these six pumps. However, this is not true of ST11, a lineage of , which is primarily composed of the highly virulent important human pathogen, O157:H7. Here we show that is absent from the pangenome of ST11 and that this lineage of has a highly conserved insertion within the gene, which when translated encodes 13 amino acids and two stop codons. This insertion was found to be present in 97.59 % of 1787 ST11 genome assemblies. Non-function of AcrF in ST11 was confirmed in the laboratory as complementation with from ST11 was unable to restore AcrF function in K-12 substr. MG1655 Δ Δ. This shows that the complement of RND efflux pumps present in laboratory bacterial strains may not reflect the situation in virulent strains of bacterial pathogens.
是一种兼性厌氧菌，存在于广泛的环境中。通常被描述为实验室的主力，是迄今为止特征描述最全面的细菌物种之一，但我们的大部分理解来自于涉及实验室菌株 K-12 的研究。耐药-结节-分裂外排泵存在于革兰氏阴性菌中，可以输出多种底物，包括抗生素。K-12 有六个 RND 泵；AcrB、AcrD、AcrF、CusA、MdtBC 和 MdtF，经常有报道称所有 菌株都具有这六个泵。然而，对于 ST11 来说并非如此，ST11 是 的一个谱系，主要由高度毒力的重要人类病原体 O157:H7 组成。在这里，我们表明 缺失于 ST11 的泛基因组中，并且该谱系的 基因内存在高度保守的插入，翻译时编码 13 个氨基酸和两个终止密码子。该插入在 1787 个 ST11 基因组组装中的 97.59%中存在。在实验室中证实了 ST11 中 AcrF 的失活，因为来自 ST11 的 AcrF 的互补无法在 K-12 substr.MG1655 ΔΔ 中恢复 AcrF 功能。这表明实验室细菌菌株中存在的 RND 外排泵的成分可能无法反映毒力细菌病原体菌株的情况。
