National Research Council, ISPAAM, Traversa la Crucca 3, località Baldinca, 07040 Li Punti, Sassari, Italy.
Antonie Van Leeuwenhoek. 2010 Feb;97(2):143-53. doi: 10.1007/s10482-009-9396-6. Epub 2009 Nov 15.
Bacteria not proficient in nitrogen fixing symbiosis were proven able to invade root nodules of three wild legumes of the genus Hedysarum in Algeria and to be multiplying in these in place of the natural rhizobium symbionts. The involved species featured taxa known as human pathogens including: Enterobacter cloacae, Enterobacter kobei, Escherichia vulneris, Pantoea agglomerans and Leclercia adecarboxylata. A direct screening of the phenotypic determinants of virulence using human cultured cells tested positive for the traits of cytotoxicity, vital stain exclusion and adhesion to epithelia. Antibiogram analyses revealed also a complex pattern of multiple antibiotic resistances. The data suggest that legume root nodules can be a site of survival and of active multiplication for populations of mammalian pathogens, which could thus alternate between the target animal and a number of neutral plant hosts. The worldwide distribution of as yet uninvestigated legumes raises the concern that these represent a general niche that could enhance the hazards posed by microorganisms of clinical nature.
已证明不擅长固氮共生的细菌能够入侵阿尔及利亚三种野生胡芦巴属豆科植物的根瘤，并在这些根瘤中替代天然根瘤菌共生体进行繁殖。涉及的物种包括被认为是人类病原体的分类群，如阴沟肠杆菌、科氏肠杆菌、脆弱埃希氏菌、成团泛菌和产脱羧酶勒克氏菌。使用人类培养细胞直接筛选毒力表型决定因素的结果为细胞毒性、活细胞染色排除和上皮细胞黏附呈阳性。抗生素分析图谱还揭示了一种多重抗生素耐药的复杂模式。这些数据表明，豆科植物根瘤可能是哺乳动物病原体种群的存活和活跃繁殖的场所，这些病原体可以在目标动物和许多中性植物宿主之间交替。尚未研究的豆科植物在全球范围内的分布引起了人们的关注，这些植物可能代表了一个普遍的生态位，从而增加了具有临床意义的微生物带来的危害。
