Staphylococcus epidermidis causes infections associated with orthopedic implants due to its ability to establish persistent biofilms, making infections chronic and hard to treat. Extracellular vesicles (EVs) are part of the bacterial communication system, but the role of S. epidermidis-derived EVs in biofilm formation processes and survival is completely unknown. The aims of this study were (i) to investigate the effect of subinhibitory concentrations of antibiotics on vesiculation in S. epidermidis and evaluate the role of EVs in bacterial survival and adhesion under antimicrobial selective pressure and (ii) to evaluate whether EVs derived from a gentamicin-resistant S. epidermidis strain influence the susceptibility and adhesion of a gentamicin-susceptible strain. A gentamicin-susceptible (GEN^S) strain isolated from implant-associated osteomyelitis was cultured with EVs previously isolated from the same strain growing with subinhibitory concentrations of GEN (0, 0.03, and 0.06 μg × mL^–1) or with EVs from a gentamicin-resistant (GEN^R) strain. EVs were characterized regarding their size, number and protein content. The growth of S. epidermidis cultured with increasing concentrations of GEN (<=> MIC of 0.12 μg × mL^–1) was recorded, viability was determined by quantitative culturing and fluorescence staining, and biofilm biomass on polystyrene was quantified by crystal violet staining. Cells grown in subinhibitory concentrations of GEN produced a larger number of EVs of similar size but with greater protein content than cells grown in control (Ctrl) conditions (0 GEN). Under antimicrobial pressure, EVs promoted different mechanisms of antimicrobial tolerance depending on the EV and GEN concentrations. Cell adhesion to polystyrene decreased in the presence of 0 and 0.03 μg × mL^–1 GEN upon EV stimulation. Compared with Ctrl cells, cells treated with EVs from a GEN^R strain showed increased cell division during the exponential growth phase, faster maximal growth rate, shorter doubling time (8–33 min), and dramatically inhibited cell adhesion. These findings suggest that vesiculation in S. epidermidis is a survival response to subinhibitory concentrations of gentamicin. EVs may contribute to bacterial survival through their involvement (1) in the modulation of the growth rate, affecting cell division, and (2) in cell adhesion, decreasing cell attachment to polystyrene and glass.

表皮葡萄球菌由于其能够建立持久性生物膜的能力而导致与整形外科植入物有关的感染，从而使感染变得慢性且难以治疗。细胞外囊泡（EVs）是细菌通讯系统的一部分，但其作用是表皮葡萄球菌生物膜形成过程和存活过程中衍生的电动汽车是完全未知的。这项研究的目的是（i）研究亚抑制浓度的抗生素对大鼠囊泡的影响。表皮葡萄球菌 并评估电动汽车在抗菌选择压力下在细菌存活和黏附中的作用，以及（ii）评估电动汽车是否源自对庆大霉素有抗药性 表皮葡萄球菌菌株影响庆大霉素敏感性菌株的敏感性和粘附性。庆大霉素敏感性（GEN^小号）从植入物相关性骨髓炎中分离出的菌株与先前从同一菌株中分离出的EV一起培养，该菌株生长时产生亚抑制浓度的GEN（0、0.03和0.06μg×mL ^–1）或耐庆大霉素的EV（GEN^[R）应变。对电动汽车的大小，数量和蛋白质含量进行了表征。的成长表皮葡萄球菌记录以浓度递增的GEN（MIC = 0.12μg×mL ^–1）培养的细胞，通过定量培养和荧光染色确定活力，并通过结晶紫染色对聚苯乙烯上的生物膜生物量进行定量。与在对照（Ctrl）条件（0 GEN）下生长的细胞相比，以亚抑制浓度的GEN生长的细胞可产生大量相似大小但具有更大蛋白质含量的EV。在抗菌压力下，电动汽车根据电动汽车和GEN浓度促进了不同的抗菌耐受机制。在EV刺激下，当存在0和0.03μg×mL ^–1 GEN时，细胞对聚苯乙烯的粘附力降低。与Ctrl单元格相比，用GEN的EV处理的单元格^[R菌株在指数生长期显示细胞分裂增加，最大生长速度更快，加倍时间更短（8-33分钟），并显着抑制细胞粘附。这些发现表明，在表皮葡萄球菌对庆大霉素亚抑制浓度的生存反应。电动汽车可能通过参与以下因素而有助于细菌存活：（1）调节生长速度，影响细胞分裂，（2）参与细胞粘附，减少细胞与聚苯乙烯和玻璃的附着。