Resistance‐Nodulation‐Division (RND) efflux pumps are relevant determinants of Stenotrophomonas maltophilia multidrug resistance as they can extrude a broad range of antibiotics and compounds involved in virulence and physiological functions. S. maltophilia, an environmental bacterium, was shown to be associated with amoebae and able to multiply inside them. To explore whether S. maltophilia RND efflux pumps play a role when interacting with amoebae, we evaluated the effect of amoebal culture and co‐culture supernatants on the growth of S. maltophilia and the expression of sme efflux pump genes. Acanthamoeba castellanii and Willaertia magna were used as amoebal models and strain S. maltophilia BurE1 as bacterial one. Our data showed that both bacterial growth and sme gene expression were not modified by amoebal culture supernatants. On the contrary, co‐culture supernatants negatively impacted the growth of BurE1 and induced the expression of three out of eight efflux pump genes, i.e. smeE, smeN and smeZ. Finally, we evidenced the production of A. castellanii secondary metabolites, putatively belonging to the diterpene family, in the amoebal supernatant and in the co‐culture supernatant of A. castellanii and BurE1. Whether these compounds act directly as substrates of the efflux pumps and/or inducers of the sme genes need further investigations.

中文翻译：

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在变形虫和细菌共培养上清液的存在下，嗜麦芽窄食单胞菌的生长和编码基因的Sme外排泵的表达：对变形虫次生代谢产物的作用。

抵抗结瘤分区（RND）外排泵是嗜麦芽窄食单胞菌多药耐药性的相关决定因素，因为它们可以挤出涉及毒力和生理功能的多种抗生素和化合物。嗜环境链球菌，一种环境细菌，被证明与变形虫相关，并能够在其中繁殖。为了探讨嗜麦芽孢杆菌RND外排泵在与变形虫相互作用时是否发挥作用，我们评估了变形虫培养物和共培养上清液对嗜麦芽孢杆菌生长和sme外排泵基因表达的影响。棘阿米巴Castellanii和Willaertia magna将其用作变形虫模型，将嗜麦芽孢杆菌BurE1菌株用作细菌。我们的数据表明，细菌生长和sme基因表达都没有被变形虫上清液修饰。相反，共培养上清BurE1的增长造成负面影响，并引发三个出八外排泵基因的表达，即中小企业E，中小企业N和中小企业Z.最后，我们证明了生产A.阿米巴次生代谢产物，假定属于双萜家族，在变形虫上清液和A. castellanii共培养上清液中和BurE1。这些化合物是否直接充当外排泵的底物和/或sme基因的诱导剂还需要进一步研究。