Krzyżek Paweł, Opalińska Agnieszka, Migdał Paweł, Tusiewicz Kaja, Szpot Paweł, Zawadzki Marcin, Krzyżanowska Barbara, Kulus Michał Jerzy, Podhorska-Okołów Marzenna, Sobieszczańska Beata
Department of Microbiology, Faculty of Medicine, Wroclaw Medical University, Wroclaw, Poland.
Laboratory of Nanostructures, Institute of High Pressure Physics, Polish Academy of Sciences, Warsaw, Poland.
J Antimicrob Chemother. 2025 Jul 1;80(7):2032-2043. doi: 10.1093/jac/dkaf172.
Bacterial extracellular vesicles (EVs) may reduce the effectiveness of various antimicrobials; however, the impact of antibiotics on the secretion and properties of EVs produced by Helicobacter pylori has not been established.
Using clinical H. pylori strains and culture in EV-depleted media, the influence of ¼ × MIC of clarithromycin, metronidazole and levofloxacin on EV features was determined. Physicochemical properties of EVs were measured using nanoparticle tracking analysis and dynamic light scattering. Determination of fatty acid profiles of EVs and bacterial cells was performed with GC triple-quadrupole tandem MS. Bacteria and EVs were observed by scanning and transmission electron microscopy, respectively.
Antibiotic stress induced in H. pylori affects the secretion intensity and physicochemical features of EVs secreted by this bacterium in a strain- and antibiotic-dependent manner. Exposure to ¼ × MIC of metronidazole or levofloxacin increased the secretion of EVs and contributed to significant changes in their fatty acid profile, whereas treatment with ¼ × MIC of clarithromycin did not induce such changes. Regardless of the culture conditions and the strain analysed, the existence of a conservative process of selective packaging of C17:0 fatty acids into EVs and a substantial limitation of this phenomenon for C14:0, C18:1 and C19c:0 was demonstrated.
This is the first study showing the modulatory effect of antibiotic stress on the secretion and physicochemical features of EVs produced by H. pylori, as well as the first to suggest the involvement of EVs in maintaining the appropriate membrane fatty acid composition of this bacterium.
细菌细胞外囊泡（EVs）可能会降低多种抗菌药物的有效性；然而，抗生素对幽门螺杆菌产生的EVs的分泌及特性的影响尚未明确。
使用临床幽门螺杆菌菌株并在无EVs的培养基中培养，测定克拉霉素、甲硝唑和左氧氟沙星的1/4×最低抑菌浓度（MIC）对EVs特性的影响。使用纳米颗粒跟踪分析和动态光散射测量EVs的物理化学性质。采用气相色谱三重四极杆串联质谱法测定EVs和细菌细胞的脂肪酸谱。分别通过扫描电子显微镜和透射电子显微镜观察细菌和EVs。
幽门螺杆菌受到的抗生素应激以菌株和抗生素依赖的方式影响该细菌分泌的EVs的分泌强度和物理化学特征。暴露于1/4×MIC的甲硝唑或左氧氟沙星会增加EVs的分泌，并导致其脂肪酸谱发生显著变化，而用1/4×MIC的克拉霉素处理则不会引起此类变化。无论培养条件和分析的菌株如何，均证明存在将C17:0脂肪酸选择性包装到EVs中的保守过程，且该现象对于C14:0、C18:1和C19c:0有实质性限制。
这是第一项显示抗生素应激对幽门螺杆菌产生的EVs的分泌和物理化学特征具有调节作用的研究，也是第一项提示EVs参与维持该细菌适当膜脂肪酸组成的研究。
