鞭毛是影响粘附的艰难梭菌的主要运动结构,殖民,和人类胃肠道中艰难梭菌的毒力。FliL蛋白是与鞭毛基质结合的单个跨膜蛋白。本研究旨在探讨FliL编码基因鞭毛基体相关FliL家族蛋白(FliL)对艰难梭菌表型的影响。使用等位基因偶联交换(ACE)和标准分子克隆方法构建了FLIL基因缺失突变体(ΔFLIL)及其相应的互补菌株(::FLIL)。生理特性的差异,如生长概况,抗生素敏感性,耐pH值,运动性,并研究了突变体和野生型菌株(CD630)之间的孢子生产能力。成功构建了ΔfliL突变体和::fliL互补菌株。在比较菌株CD630的表型后,和::FLIL,结果表明,ΔfliL突变体的生长速率和最大生物量比CD630降低。ΔfIL突变体对阿莫西林的敏感性增加,氨苄青霉素,和诺氟沙星.其对卡那霉素和四环素类抗生素的敏感性下降,抗生素敏感性部分恢复到::FLIL菌株中CD630菌株的水平。此外,在ΔfliL突变体中,运动性显着降低。有趣的是,即使与CD630菌株相比,::flL菌株的运动性也显着增加。此外,在pH5或9时,ΔfliL突变体的pH耐受性分别显着增加或降低。最后,与CD630菌株相比,ΔfIL突变体的孢子形成能力大大降低,并在::fIL菌株中恢复。我们得出的结论是,fIL基因的缺失显着降低了艰难梭菌的游泳运动,这表明FLIL基因对艰难梭菌的运动至关重要。FIL基因缺失显著降低了孢子产量,细胞生长率,对不同抗生素的耐受性,酸度,艰难梭菌的碱性环境。这些生理特征与宿主肠道中的生存优势密切相关,这与它的致病性有关。因此,我们认为,FLIL基因的功能与其运动性密切相关,殖民,环境耐受性,和孢子的生产能力,从而影响艰难梭菌的致病性。
Flagella are the main motility structure of Clostridioides difficile that affects the adhesion, colonization, and virulence of C. difficile in the human gastrointestinal tract. The FliL protein is a single transmembrane protein bound to the flagellar matrix. This study aimed to investigate the effect of the FliL encoding gene flagellar basal body-associated FliL family protein (fliL) on the phenotype of C. difficile. The fliL gene deletion mutant (ΔfliL) and its corresponding complementary strains (: : fliL) were constructed using allele-coupled exchange (ACE) and the standard molecular clone method. The differences in physiological properties such as growth profile, antibiotic sensitivity, pH resistance, motility, and spore production ability between the mutant and wild-type strains (CD630) were investigated. The ΔfliL mutant and the : : fliL complementary strain were successfully constructed. After comparing the phenotypes of strains CD630, ΔfliL, and : : fliL, the results showed that the growth rate and maximum biomass of ΔfliL mutant decreased than that of CD630. The ΔfliL mutant showed increased sensitivity to amoxicillin, ampicillin, and norfloxacin. Its sensitivity to kanamycin and tetracycline antibiotics decreased, and the antibiotic sensitivity partially returned to the level of CD630 strain in the : : fliL strain. Moreover, the motility was significantly reduced in the ΔfliL mutant. Interestingly, the motility of the : : fliL strain significantly increased even when compared to that of the CD630 strain. Furthermore, the pH tolerance of the ΔfliL mutant significantly increased or decreased at pH 5 or 9, respectively. Finally, the sporulation ability of ΔfliL mutant reduced considerably compared to the CD630 strain and recovered in the : : fliL strain. We conclude that the deletion of the fliL gene significantly reduced the swimming motility of C. difficile, suggesting that the fliL gene is essential for the motility of C. difficile. The fliL gene deletion significantly reduced spore production, cell growth rate, tolerance to different antibiotics, acidity, and alkalinity environments of C. difficile. These physiological characteristics are closely related to the survival advantage in the host intestine, which is correlated with its pathogenicity. Thus, we suggested that the function of the fliL gene is closely related to its motility, colonization, environmental tolerance, and spore production ability, which consequently affects the pathogenicity of C. difficile.