Institute of Ecology and Genetics of Microorganisms Ural Branch Russian Academy of Sciences, 614081 Perm, Russia.
LLC Centralized Clinical Diagnostic Laboratory, 614025 Perm, Russia.
Int J Mol Sci. 2023 Sep 24;24(19):14497. doi: 10.3390/ijms241914497.
Biofilms as a form of adaptation are beneficial for bacterial survival and may be hot spots for horizontal gene transfer, including conjugation. The aim of this research was to characterize the biofilm biomass, viable cell ratios and conjugative transfer of the pOX38 plasmid, an F-plasmid derivative, from the N4i pOX38 strain (donor) into a uropathogenic DL82 strain (recipient) within dual-species biofilms with one of the following opportunistic pathogenic bacteria: , or . Dual-species biofilms of with or but not were more massive and possessed more exopolysaccharide matrix compared to single-species biofilms of donor and recipient cells. Correlation between biofilm biomass and exopolysaccharide matrix was rs = 0.888 in dual-species biofilms. In dual-species biofilm with the proportion of was the highest, while in the biofilm with and , the was less abundant. The conjugative frequencies of plasmid transfer in dual-species biofilms of with and were reduced. A decrease in conjugative frequency was also observed when cell-free supernatants (CFSs) of and were added to the conjugation mixture. Further, the activity of the autoinducer AI-2 in the CFSs of the conjugation mixture was reduced when bacteria or CFSs of and were added to the conjugation mixture. Hence, the intercellular and interspecies interactions in dual-species biofilms depend on the partners involved.
生物膜作为一种适应形式有利于细菌的生存，并且可能是水平基因转移（包括接合）的热点。本研究的目的是描述生物膜生物量、活细胞比例以及 pOX38 质粒（F 质粒衍生物）从 N4i pOX38 菌株（供体）到尿路致病性 DL82 菌株（受体）的接合转移，该质粒存在于与以下一种机会致病菌的双物种生物膜中： 、 或 。与单物种生物膜相比，与 或 但不是 的双物种生物膜的 更为密集，并且具有更多的胞外多糖基质。双物种生物膜中生物膜生物量与胞外多糖基质之间的相关性为 rs = 0.888。在与 形成的双物种生物膜中， 的比例最高，而在与 和 形成的生物膜中， 的丰度较低。与 和 形成的双物种生物膜中的质粒转移的接合频率降低。当将 和 的无细胞上清液（CFS）添加到 接合混合物中时，也观察到接合频率降低。此外，当将 和 的细菌或 CFS 添加到 接合混合物中时，该 接合混合物中 CFS 中的自诱导物 AI-2 的活性降低。因此，双物种生物膜中的细胞间和种间相互作用取决于所涉及的伙伴。
