Dipartimento di Bioscienze, Università degli Studi di Milano, Milano, Italy.
Istituto di Tecnologie Biomediche-CNR, Segrate, Italy.
Sci Rep. 2018 Nov 15;8(1):16912. doi: 10.1038/s41598-018-35087-y.
Pseudomonas spp. are endowed with a complex pathway for glucose uptake that relies on multiple transporters. In this work we report the construction and characterization of Pseudomonas aeruginosa single and multiple mutants with unmarked deletions of genes encoding outer membrane (OM) and inner membrane (IM) proteins involved in glucose uptake. We found that a triple ΔgltKGF ΔgntP ΔkguT mutant lacking all known IM transporters (named GUN for Glucose Uptake Null) is unable to grow on glucose as unique carbon source. More than 500 genes controlling both metabolic functions and virulence traits show differential expression in GUN relative to the parental strain. Consistent with transcriptomic data, the GUN mutant displays a pleiotropic phenotype. Notably, the genome-wide transcriptional profile and most phenotypic traits differ between the GUN mutant and the wild type strain irrespective of the presence of glucose, suggesting that the investigated genes may have additional roles besides glucose transport. Finally, mutants carrying single or multiple deletions in the glucose uptake genes showed attenuated virulence relative to the wild type strain in Galleria mellonella, but not in Caenorhabditis elegans infection model, supporting the notion that metabolic functions may deeply impact P. aeruginosa adaptation to specific environments found inside the host.
铜绿假单胞菌具有复杂的葡萄糖摄取途径，依赖于多种转运蛋白。在这项工作中，我们报告了铜绿假单胞菌单突变体和多突变体的构建和特性，这些突变体的基因缺失了编码参与葡萄糖摄取的外膜（OM）和内膜（IM）蛋白的无标记基因。我们发现，一个三重ΔgltKGFΔgntPΔkguT 突变体缺乏所有已知的 IM 转运蛋白（命名为葡萄糖摄取缺失的 GUN），无法以葡萄糖作为唯一碳源生长。超过 500 个控制代谢功能和毒力特性的基因在 GUN 中与亲本菌株相比表现出差异表达。与转录组数据一致，GUN 突变体表现出多种表型。值得注意的是，无论是否存在葡萄糖，GUN 突变体和野生型菌株之间的全基因组转录谱和大多数表型特征都不同，这表明所研究的基因除了葡萄糖转运外可能还有其他作用。最后，携带葡萄糖摄取基因单或多缺失的突变体在金斑蝶幼虫中的毒力相对野生型菌株减弱，但在秀丽隐杆线虫感染模型中没有减弱，这支持了代谢功能可能深刻影响铜绿假单胞菌适应宿主内特定环境的观点。
