PDF(Pubmed)
Abstract：
In nature, Listeria may interact competitively and cooperatively with other organisms, resulting in unique spatial organization and functions for cells within the community. This study was undertaken to characterize the biofilm architecture of binary biofilms of Listeria monocytogenes and Lactobacillus species and to assess their effect on the survival of Listeria during exposure to hypochlorite. Three L. monocytogenes strains, ATCC 19115 (Lm5), ATCC 19117 (Lm7), and Coleslaw (LmC), were selected and combined individually with three Lactobacillus strains: L. fermentum (Lf), L. bavaricus (Lb), and L. plantarum (Lp). In binary Lm-Lp biofilms, the Lm cell counts were similar to single-species biofilms (8.5 log CFU/well), and the Lp cell numbers declined by 1.0 log CFU/well. In the presence of Lb, the Lm cell counts were reduced by 1.5 log CFU/well (p < 0.05), whereas the Lf cell counts increased at least by 3.5 log CFU/well. Confocal laser scanning microscopy (CLSM) determined that interspecies interactions significantly affected the spatial organization of three binary biofilms. Biofilm surface-to-volume ratio increased from 0.8 μm2/μm3 for Lm5 in the monoculture to 2.1 μm2/μm3 for Lm5-Lp in the dual-species model (p < 0.05), and was characterized by a thicker structure with a largely increased surface area. Biofilm roughness increased from 0.2 for Lm7 to 1.0 for Lm7-Lb biofilms (p < 0.05), which appeared as interspecific segregation. Biofilm thickness increased from 34.2 μm for LmC to 46.3 μm for LmC-Lf (p < 0.05), which produced flat and compact structures that covered the entire surface available. The biomass of the extracellular matrix was higher in the case of some binary biofilms (p < 0.05); however, this effect was dependent upon the species pair. When treated with hypochlorite, Lm5 in binary biofilms had an approximately 1.5 log CFU/well greater survival than individually. The unique spatial organization and greater protein production may explain the protective effect of Lp after hypochlorite exposure.
摘要：
在大自然中,李斯特菌可能与其他生物竞争和合作地相互作用，导致社区内细胞独特的空间组织和功能。进行这项研究是为了表征单核细胞增生李斯特菌和乳杆菌属的二元生物膜的生物膜结构，并评估它们在暴露于次氯酸盐期间对李斯特菌存活的影响。三个单核细胞增生李斯特菌菌株，ATCC19115(Lm5),ATCC19117(Lm7),和凉拌卷心菜(LmC)，选择并分别与三种乳杆菌菌株组合：发酵乳杆菌（Lf），L.巴伐利亚（Lb），和植物乳杆菌(Lp)。在二元Lm-Lp生物膜中，Lm细胞计数与单物种生物膜相似（8.5logCFU/孔），Lp细胞数下降了1.0logCFU/孔。在Lb面前,Lm细胞计数减少1.5logCFU/孔（p<0.05），而Lf细胞计数至少增加了3.5logCFU/孔。共聚焦激光扫描显微镜（CLSM）确定种间相互作用显着影响三个二元生物膜的空间组织。生物膜表面体积比从单质培养中Lm5的0.8μm2/μm3增加到双物种模型中Lm5-Lp的2.1μm2/μm3（p<0.05），其特征是较厚的结构，表面积大大增加。生物膜粗糙度从Lm7的0.2增加到Lm7-Lb生物膜的1.0（p<0.05），表现为种间隔离。生物膜厚度从LmC的34.2μm增加到LmC-Lf的46.3μm（p<0.05），它产生了扁平和紧凑的结构，覆盖了整个表面。在某些二元生物膜的情况下，细胞外基质的生物量较高（p<0.05）；然而，这种影响取决于物种对。用次氯酸盐处理时，二元生物膜中的Lm5具有比单独的大约1.5logCFU/高得多的存活率。独特的空间组织和更大的蛋白质产量可以解释次氯酸盐暴露后Lp的保护作用。
