大肠杆菌肠道感染病理类型的特点是不同的粘附模式,包括最近描述的结块粘连表型。这里,我们鉴定并表征了导致大肠杆菌菌株4972的凝块粘附的遗传因素。在这种菌株中,发现粘附细菌的转录组和蛋白质组与上清液中的浮游细菌不同。相对于浮游细菌,转录组中共有622个基因在存在于团块中的细菌中差异表达。7个靶向破坏的基因在不同的致病型和非致病性大肠杆菌中具有可变的分布,pilV和spnT基因在大多数群体中频率最低或不存在。五个差异表达基因的缺失(Δ),flgH,ffp,pilV,spnT,和yggT,受影响的运动性,附着力,或抗生素压力。ΔflgH表现出80%的降低,ΔyggT表现出184%的附着力增加,在补充之后,附着力显著降低至13%。ΔflgH失去了运动性,并在补充时再生,而Δffp的运动性明显增加,重新引入相同的基因将其降低到野生型水平。Δffp和ΔspnT产生的团块具有更强的抗性并保护细菌,ΔspnT在氨苄青霉素胁迫保护方面显示出最佳的团块形成。ΔyggT对庆大霉素的耐受性最低,抗生素的压力完全消除了细菌。总的来说,我们能够研究团块形成对细胞表面粘附和抗菌耐受性的影响,与对所选择的抗生素敏感性的凝块形成至关重要的几个因素的贡献。
目的:该研究探索了大肠杆菌中类似生物膜的凝块粘附表型,以及抗生素敏感性的各种因素和含义。该表型使细菌能够在高浓度抗生素的冲击下存活。转录组和蛋白质组的分布允许在团块中的粘附细菌和上清液中的浮游细菌之间进行区分。粘附细菌和浮游细菌之间差异表达的基因的缺失突变体,即,flgH,ffp,pilV,spnT,和yggT,各自的互补在转型中巩固了他们在多种能力中的作用。ffp,一个没有特征的基因,在结块状态下参与运动和对氨苄青霉素的抗性。这项工作还首次确认了yggT基因在粘附中的作用及其参与对另一种氨基糖苷类抗生素的敏感性,即,庆大霉素.总的来说,该研究有助于生物膜样粘附表型的机制以及对抗菌治疗失败和大肠杆菌感染的理解。
Escherichia coli intestinal infection pathotypes are characterized by distinct adhesion patterns, including the recently described clumpy adhesion phenotype. Here, we identify and characterize the genetic factors contributing to the clumpy adhesion of E. coli strain 4972. In this strain, the transcriptome and proteome of adhered bacteria were found to be distinct from planktonic bacteria in the supernatant. A total of 622 genes in the transcriptome were differentially expressed in bacteria present in clumps relative to the planktonic bacteria. Seven genes targeted for disruption had variable distribution in different pathotypes and nonpathogenic E. coli, with the pilV and spnT genes being the least frequent or absent from most groups. Deletion (Δ) of five differentially expressed genes, flgH, ffp, pilV, spnT, and yggT, affected motility, adhesion, or antibiotic stress. ΔflgH exhibited 80% decrease and ΔyggT depicted 184% increase in adhesion, and upon complementation, adhesion was significantly reduced to 13%. ΔflgH lost motility and was regenerated when complemented, whereas Δffp had significantly increased motility, and reintroduction of the same gene reduced it to the wild-type level. The clumps produced by Δffp and ΔspnT were more resistant and protected the bacteria, with ΔspnT showing the best clump formation in terms of ampicillin stress protection. ΔyggT had the lowest tolerance to gentamicin, where the antibiotic stress completely eliminated the bacteria. Overall, we were able to investigate the influence of clump formation on cell surface adhesion and antimicrobial tolerance, with the contribution of several factors crucial to clump formation on susceptibility to the selected antibiotics.
OBJECTIVE: The study explores a biofilm-like clumpy adhesion phenotype in Escherichia coli, along with various factors and implications for antibiotic susceptibility. The phenotype permitted the bacteria to survive the onslaught of high antibiotic concentrations. Profiles of the transcriptome and proteome allowed the differentiation between adhered bacteria in clumps and planktonic bacteria in the supernatant. The deletion mutants of genes differentially expressed between adhered and planktonic bacteria, i.e., flgH, ffp, pilV, spnT, and yggT, and respective complementations in trans cemented their roles in multiple capacities. ffp, an uncharacterized gene, is involved in motility and resistance to ampicillin in a clumpy state. The work also affirms for the first time the role of the yggT gene in adhesion and its involvement in susceptibility against another aminoglycoside antibiotic, i.e., gentamicin. Overall, the study contributes to the mechanisms of biofilm-like adhesion phenotype and understanding of the antimicrobial therapy failures and infections of E. coli.